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Introduction

This privacy notice describes the handling of all personal data we process. The Department for Environment, Food and Rural Affairs (Defra) is the controller.

Department for Environment, Food and Rural Affairs
Seacole Building
2 Marsham Street
London
SW1P 4DF

If you need further information about how we use your personal data and your associated rights you can contact the DWI Enquires Team at dwi.enquiries@defra.gov.uk or at the above address.

The data protection officer for Defra is responsible for checking that we comply with legislation. You can contact them at DefraGroupDataProtectionOfficer@defra.gov.uk or at the above address.

This policy only relates to the personal data that DWI collects and processes, or otherwise controls. We are not responsible for external organisations that may link to DWI’s web pages. For more information concerning external agencies and stakeholders please visit the relevant privacy statement on their own web pages.

Who we are

The DWI is committed to the responsible handling and security of personal data. Your privacy is important to us and protected in law through the UK General Data Protection Regulation (UK GDPR) and the Data Protection Act (DPA 2018).

Our website address is: https://www.dwi.gov.uk.

What is personal data?

Personal data is data which identifies an individual directly or indirectly, by reference to an identifier such as their name or a reference number.

When will we collect your information?

The DWI may collect your personal data in a number of ways. Below are some examples

  • Visitors to our website
  • In response to queries you raise
  • Correspondence and other forms of contact with the DWI for general purposes
  • Correspondence and other forms of contact with the DWI in connection with the DWI’s statutory duties as the drinking water quality regulator, for example when a consumer contacts us because they are unhappy with their water supplier’s investigation into a drinking water quality concern.
  • Under certain circumstances, water suppliers provide consumer contact data to the DWI, for example if consumers have complained to their water supplier because of a drinking water quality problem. The DWI may contact affected consumers about the issue to obtain further information.
  • Data submitted by local authorities on private water supplies in their area.
  • Job applicants and our current and former employees, liaison contacts, contractors and secondees.

Why we use your information

We process your personal data to carry out our statutory duties as the regulator of public drinking water supplies in England and Wales to provide assurance that they are safe and acceptable to consumers.

How and when we might share your personal data

We will only share personal data with third parties for the purposes of our public tasks, as set out in the Water Industry Act 1991, to comply with a legal requirement or in exceptional circumstances to protect individuals from harm or injury. We may share your personal data with other organisations in the Defra group, such as the Environment Agency, other Government departments, other regulators and other public bodies. This will only be necessary for the performance of tasks carried out in the public interest as permitted by legislation.  For example, with prosecuting lawyers in their role of supporting us when we suspect an offence has taken place under the Water Industry Act 1991 or the Water Supply (Water Quality) Regulations 2016 (England) as amended and Water Supply (Water Quality) Regulations 2018 (Wales) as amended. Where personal data is provided in the form of a formal witness statement, it may be made public during court proceedings.  Other personal data may be disclosed to the defence as unused material, as required by law.

Transfers of personal data outside of the UK

We do not transfer any personal data outside of the UK.

Information processed through different media

Telephone calls

Telephone calls to and from the DWI are not recorded. We do have a voicemail system where messages for call back are received. Once the information has been retrieved for assigning to the relevant DWI Team, they are then deleted from the voicemail system.

Emails

Emails to the DWI are normally received by our Enquiries Team at dwi.enquiries@defra.gov.uk. The emails are processed in order for us to respond and deal with your query. Once your enquiry is complete, we will keep your personal data in accordance with our retention schedule.

Analytical Cookies

If you visit our website, we will set a temporary cookie to determine if your browser accepts cookies. This cookie contains no personal data and is discarded when you close your browser.

Google’s privacy policy

How to contact us

For enquiries, for example to tell us your details are inaccurate or incomplete, to ask to see the data we hold about you, or to withdraw your consent or request your personal data be deleted, please contact our Enquiries Team at dwi.enquiries@defra.gov.uk.

To make a complaint about how your personal data has been handled please follow Defra’s complaints process.

To report a data breach, contact the Defra Helpline on 03459 33 55 77 (UK) or +44 20 7238 6951 (from outside the UK) or online. If you are unhappy with our response or if you need any advice you should contact the Information Commissioner’s Office (ICO) who are the supervisory authority: The ICO can be contacted using the following link: ICO.

HomePage V2

The Drinking Water Inspectorate (DWI) was formed in 1990 to provide independent reassurance that water supplies in England and Wales are safe and drinking water quality is acceptable to consumers.

Drinking Water 2021

Safe, clean drinking water is vital to public health and the wellbeing of our society, now and into the future. This is the central tenet of the vision and strategy of the Drinking Water Inspectorate. Drinking Water 2021 published in July 2022.

Triennial Reports 2017-2019

Three yearly report for both England and Wales on the quality of drinking water to inform consumers

05

Regions in England and Wales

25

Water Companies

Use our map to find your local water company

Find contact details, report a problem, look at incidents in your area.

See ongoing improvement in your area, how your water company is improving and find the water quality in your area.

Find your local company

Contact Us


Water quality

If you are concerned about the quality of your drinking water you should contact your water company in the first instance. A number for your water company can be found here.

 

Learn more about your water


The Drinking Water Inspectorate provides information and advice to consumers on the quality of drinking water.

Advice for finding a plumber
Algae in drinking water
Animals in drinking water
Bills and compensation
Blue water/Copper in drinking water
Boil water notice
Bottled water
Chlorine

View all leaflets

Drinking Water Inspectorate

The Drinking Water Inspectorate (DWI) was formed in 1990 to provide independent reassurance that water supplies in England and Wales are safe and drinking water quality is acceptable to consumers.

Drinking Water 2023

Safe, clean drinking water is vital to public health and the wellbeing of our society, now and into the future. This is the central tenet of the vision and strategy of the Drinking Water Inspectorate. Drinking Water 2023 published in July 2024.

Triennial Reports 2020-2022

Three yearly report for both England and Wales on the quality of drinking water to inform consumers.

05

Regions in England and Wales

25

Water Companies

Use our map to find your local water company

Find contact details, report a problem, look at incidents in your area.

See ongoing improvement in your area, how your water company is improving and find the water quality in your area.

Find your local company

Contact Us


Water quality

If you are concerned about the quality of your drinking water you should contact your water company in the first instance. A number for your water company can be found here.

 

Learn more about your water


The Drinking Water Inspectorate provides information and advice to consumers on the quality of drinking water.

Advice for finding a plumber
Algae in drinking water
Animals in drinking water
Bills and compensation
Blue water/Copper in drinking water
Boil water notice
Bottled water
Chlorine

View all leaflets

SVT (Severn Trent Water Ltd)

Report Data Range: For the whole year 2021

Table 1: Quality of water leaving service treatment works – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

Nitrite (Total)

A013B

0.1 mg NO2/l

1,567

0

<0.005

<0.013

0

Totals

1,567

0

Table 2: Quality of water leaving service treatment works – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

22,760

1

0

0

1

Total Coliforms (Confirmed)

C001

0 number/100 ml

22,760

6

0

0

6

Totals

45,520

7

Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

22,759

N/A

0

2

Residual Disinfectant – Free

C009

No abnormal change

22,762

N/A

0.17

1.04

Residual Disinfectant – Total

C010

No abnormal change

520

N/A

0.1742

0.5958

Turbidity – Indicator

A002A

1 NTU

22,755

2

<0.12

<0.24

Totals

68,796

2

Table 4: Quality of water leaving service reservoirs – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of reservoirs failing standard

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

22,481

1

0

0

1

Total Coliforms (Confirmed)

C001

0 number/100 ml

22,481

3

0

0

0

Totals:

44,962

4

Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

22,481

N/A

0

53

Residual Disinfectant – Free

C009

No abnormal change

22,481

N/A

0.06

0.61

Residual Disinfectant – Total

C010

No abnormal change

1,420

N/A

0.13

0.84

Totals:

46,382

0

Table 6: Quality of water leaving bulk supply points – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of supply point with failures

1 2-Dichloroethane (Total)

F001

3 µg/l

1,003

0

<0.24

<0.3

0

Benzene (Total)

F002

1 µg/l

1,003

0

<0.06

<0.12

0

Boron

D005A

1 mg B/l

1,003

0

<0.011

0.153

0

Cyanide (Total)

B003

50 µg CN/l

1,003

0

<3.6

<3.6

0

Mercury (Total)

B005

1 µg Hg/l 

1,003

0

<0.034

<0.034

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

470

0

0

0.09287

0

Pesticides 2 4-D

P020

0.1 µg/l

267

0

<0.009

<0.011

0

Pesticides 2 4-DB

P082

0.1 µg/l

267

0

<0.016

<0.016

0

Pesticides 2,3,6-Tba

P074

0.1 µg/l

267

0

<0.027

<0.027

0

Pesticides Aldrin

P002

0.03 µg/l

284

0

<0.003

<0.003

0

Pesticides Asulam

P133

0.1 µg/l

299

0

<0.013

<0.013

0

Pesticides Atrazine

P004

0.1 µg/l

333

0

<0.011

0.02866

0

Pesticides Azoxystrobin

P227

0.1 µg/l

267

0

<0.004

<0.004

0

Pesticides Benazolin (Total)

P138

0.1 µg/l

267

0

<0.007

0.00932

0

Pesticides Bentazone

P006

0.1 µg/l

339

0

<0.006

0.0152

0

Pesticides Boscalid

P231

0.1 µg/l

267

0

<0.007

<0.007

0

Pesticides Bromoxynil

P008

0.1 µg/l

267

0

<0.011

<0.011

0

Pesticides Carbendazim (Total)

P150

0.1 µg/l

267

0

<0.011

<0.011

0

Pesticides Carbetamide 

P010

0.1 µg/l

267

0

<0.012

<0.012

0

Pesticides Chloridazon

P162

0.1 µg/l

283

0

<0.004

0.005

0

Pesticides Chlormequat

P163

0.1 µg/l

268

0

<0.003

0.00531

0

Pesticides Chlortoluron

P014

0.1 µg/l

267

0

<0.012

<0.012

0

Pesticides Clopyralid

P018

0.1 µg/l

299

0

<0.009

0.043

0

Pesticides Cyproconazole

P207

0.1 µg/l

267

0

<0.007

<0.007

0

Pesticides Diazinon

P024

0.1 µg/l

267

0

<0.01

<0.01

0

Pesticides Dicamba

P025

0.1 µg/l

267

0

<0.015

<0.015

0

Pesticides Dichlorprop

P026

0.1 µg/l

267

0

<0.009

<0.009

0

Pesticides Dieldrin

P028

0.03 µg/l

285

0

<0.008

<0.008

0

Pesticides Diflufenican

P157

0.1 µg/l

267

0

<0.01

<0.01

0

Pesticides Dimethenamid – P

P265

0.1 µg/l

267

0

<0.006

<0.006

0

Pesticides Diuron

P032

0.1 µg/l

267

0

<0.013

<0.013

0

Pesticides Epoxyconazole

P217

0.1 µg/l

275

0

<0.007

<0.007

0

Pesticides Ethofumersate

P221

0.1 µg/l

267

0

<0.015

<0.015

0

Pesticides Flufenacet

P230

0.1 µg/l

267

0

<0.005

0.00532

0

Pesticides Fluroxypyr

P040

0.1 µg/l

267

0

<0.006

0.013

0

Pesticides Flusilazole

P159

0.1 µg/l

99

0

<0.009

<0.009

0

Pesticides Flutriafol

P039

0.1 µg/l

275

0

<0.015

<0.015

0

Pesticides Fosthiazate

P254

0.1 µg/l

48

0

<0.012

<0.012

0

Pesticides Glyphosate

P042

0.1 µg/l

268

0

<0.015

<0.03

0

Pesticides Heptachlor

P043

0.03 µg/l

284

0

<0.003

<0.003

0

Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

P044

0.03 µg/l

284

0

0

0

0

Pesticides Isoproturon

P048

0.1 µg/l

267

0

<0.011

<0.011

0

Pesticides Linuron

P051

0.1 µg/l

267

0

<0.012

<0.012

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

267

0

<0.006

0.01664

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

275

0

<0.005

0.014

0

Pesticides Metalaxyl

P209

0.1 µg/l

283

0

<0.007

0.015

0

Pesticides Metaldehyde

P226

0.1 µg/l 

316

0

<0.006

0.052

0

Pesticides Metamitron

P194

0.1 µg/l

283

0

<0.012

<0.012

0

Pesticides Metazachlor

P203

0.1 µg/l 

267

0

<0.011

0.012

0

Pesticides Metribuzin

P152

0.1 µg/l

267

0

<0.004

<0.004

0

Pesticides Oxadixyl

P154

0.1 µg/l

291

0

<0.004

0.07924

0

Pesticides Pendimethalin

P118

0.1 µg/l

267

0

<0.012

<0.012

0

Pesticides Propiconazole

P068

0.1 µg/l

267

0

<0.014

<0.014

0

Pesticides Propyzamide

P071

0.1 µg/l

275

0

<0.011

<0.011

0

Pesticides Prosulfocarb

P243

0.1 µg/l

267

0

<0.005

<0.005

0

Pesticides Quinmerac

P224

0.1 µg/l

283

0

<0.009

<0.009

0

Pesticides Simazine

P073

0.1 µg/l

270

0

<0.011

<0.011

0

Pesticides Tebuconazole

P177

0.1 µg/l

267

0

<0.006

<0.006

0

Pesticides Terbutryn

P077

0.1 µg/l

267

0

<0.009

<0.009

0

Pesticides Triadimefon

P078

0.1 µg/l

267

0

<0.012

<0.012

0

Pesticides Tri-allate

P079

0.1 µg/l

268

0

<0.003

<0.003

0

Pesticides Triclopyr

P131

0.1 µg/l

267

0

<0.011

<0.011

0

Totals

20,496

0

Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Chloride

D002A

250 mg Cl/l

1,003

0

8.804

167.44

Gross Alpha

F004

0.1 Bq/l

49

18

<0.025

0.48

Gross Beta

F005

1 Bq/l

49

0

0.028

0.177

Sulphate

A007

250 mg SO4/l

1,003

0

6.112

149.412

Total Organic Carbon

A017

No abnormal change

1,003

N/A

<0.8

3.396

Tritium

F006

100 Bq/l

33

0

<3

<3

Totals

3,140

18

Table 9: Quality of water at consumer’s tap (zones) – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of zones failing standard

1 2-Dichloroethane (Total)

F001

3 µg/l

136

0

<0.24

<0.3

0

Antimony

B008A

5 µg Sb/l

1,572

0

<0.04

0.49

0

Arsenic (Total)

B001A

10 µg As/l

1,572

0

0.07

6.4535

0

Benzene (Total)

F002

1 µg/l

136

0

<0.06

<0.12

0

Benzo[a]Pyrene (Total)

D007

0.01 µg/l

1,572

0

<0.00074

<0.001

0

Boron

D005A

1 mg B/l

136

0

<0.011

0.08763

0

Bromate

F003

10 µg BrO3/l

1,572

0

<0.53

2.26

0

Cadmium (Total)

B002

5 µg Cd/l

1,572

0

<0.02

0.6208

0

Chromium (Total)

B004

50 µg Cr/l

1,572

0

<0.3

<2.1

0

Copper (Total)

A024A

2 mg Cu/l

1,572

0

<0.0014

0.565814

0

Cyanide (Total)

B003

50 µg CN/l

136

0

<3.6

<3.6

0

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

21,663

1

0

0

1

Enterococci (Confirmed)

C003

0 number/100 ml

1,572

1

0

0

1

Fluoride (Fluoridated)

A027A

1.2 mg F/l

205

56

0.08

1.0694

23

Fluoride (Total)

A027

1.5 mg F/l

1,572

0

<0.08

1.02

0

Lead (10 – will apply 25.12.2013)

B007B

10 µg Pb/l

1,572

5

<0.13

6.1888

5

Mercury (Total)

B005

1 µg Hg/l 

136

0

<0.034

<0.034

0

Nickel (Total) 

B006A 

20 µg Ni/l

1,572

2

<0.5

9.454

2

Nitrate (Total)

A012

50 mg NO3/l

1,788

0

<2.01

41.5233

0

Nitrite – Consumer’s Taps

A013A

0.5 mg NO2/l

1,788

0

<0.005

0.02611

0

Nitrite/Nitrate formula

A013C

1 mg/l

1,788

0

<0.04

0.83

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

136

0

0

0.1103

0

Pesticides 2 4-D

P020

0.1 µg/l

136

0

<0.009

0.01063

0

Pesticides 2 4-DB

P082

0.1 µg/l

136

0

<0.016

<0.016

0

Pesticides 2,3,6-Tba

P074

0.1 µg/l

136

0

<0.027

<0.027

0

Pesticides Aldrin

P002

0.03 µg/l

136

0

<0.003

<0.003

0

Pesticides Asulam

P133

0.1 µg/l

136

0

<0.013

<0.013

0

Pesticides Atrazine

P004

0.1 µg/l

136

0

<0.011

<0.011

0

Pesticides Azoxystrobin

P227

0.1 µg/l

136

0

<0.004

<0.004

0

Pesticides Benazolin (Total)

P138

0.1 µg/l

136

0

<0.007

<0.007

0

Pesticides Bentazone

P006

0.1 µg/l

136

0

<0.006

<0.02364

0

Pesticides Boscalid

P231

0.1 µg/l

136

0

<0.007

<0.007

0

Pesticides Bromoxynil

P008

0.1 µg/l

136

0

<0.011

<0.011

0

Pesticides Carbendazim (Total)

P150

0.1 µg/l

136

0

<0.011

<0.011

0

Pesticides Carbetamide 

P010

0.1 µg/l

136

0

<0.012

<0.012

0

Pesticides Chloridazon

P162

0.1 µg/l

136

0

<0.004

<0.004

0

Pesticides Chlormequat

P163

0.1 µg/l

136

0

<0.003

0.02367

0

Pesticides Chlortoluron

P014

0.1 µg/l

136

0

<0.012

<0.012

0

Pesticides Clopyralid

P018

0.1 µg/l

136

0

<0.009

0.02

0

Pesticides Cyproconazole

P207

0.1 µg/l

136

0

<0.007

<0.007

0

Pesticides Diazinon

P024

0.1 µg/l

136

0

<0.01

<0.01

0

Pesticides Dicamba

P025

0.1 µg/l

136

0

<0.015

<0.02445

0

Pesticides Dichlorprop

P026

0.1 µg/l

136

0

<0.009

<0.009

0

Pesticides Dieldrin

P028

0.03 µg/l

136

0

<0.008

<0.008

0

Pesticides Diflufenican

P157

0.1 µg/l

136

0

<0.01

<0.01

0

Pesticides Dimethenamid – P

P265

0.1 µg/l

136

0

<0.006

<0.006

0

Pesticides Diuron

P032

0.1 µg/l

136

0

<0.013

<0.013

0

Pesticides Epoxyconazole

P217

0.1 µg/l

136

0

<0.007

<0.007

0

Pesticides Ethofumersate

P221

0.1 µg/l

136

0

<0.015

<0.015

0

Pesticides Flufenacet

P230

0.1 µg/l

136

0

<0.005

0.00852

0

Pesticides Fluroxypyr

P040

0.1 µg/l

136

0

<0.006

0.013

0

Pesticides Flusilazole

P159

0.1 µg/l

47

0

<0.009

<0.009

0

Pesticides Flutriafol

P039

0.1 µg/l

136

0

<0.015

<0.015

0

Pesticides Fosthiazate

P254

0.1 µg/l

136

0

<0.012

<0.012

0

Pesticides Glyphosate

P042

0.1 µg/l

136

0

<0.015

<0.03

0

Pesticides Heptachlor

P043

0.03 µg/l

136

0

<0.003

<0.003

0

Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

P044

0.03 µg/l

136

0

0

0

0

Pesticides Isoproturon

P048

0.1 µg/l

136

0

<0.011

<0.0011

0

Pesticides Linuron

P051

0.1 µg/l

136

0

<0.012

<0.012

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

136

0

<0.006

0.00863

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

136

0

<0.005

0.00926

0

Pesticides Metalaxyl

P209

0.1 µg/l

136

0

<0.007

<0.01141

0

Pesticides Metaldehyde

P226

0.1 µg/l 

136

0

<0.006

0.05463

0

Pesticides Metamitron

P194

0.1 µg/l

136

0

<0.012

<0.012

0

Pesticides Metazachlor

P203

0.1 µg/l 

136

0

<0.011

0.02178

0

Pesticides Metribuzin

P152

0.1 µg/l

136

0

<0.004

<0.00463

0

Pesticides Oxadixyl

P154

0.1 µg/l

136

0

<0.004

0.07963

0

Pesticides Pendimethalin

P118

0.1 µg/l

136

0

<0.012

<0.012

0

Pesticides Propiconazole

P068

0.1 µg/l

136

0

<0.014

<0.014

0

Pesticides Propyzamide

P071

0.1 µg/l

136

0

<0.011

0.01363

0

Pesticides Prosulfocarb

P243

0.1 µg/l

136

0

<0.005

<0.005

0

Pesticides Quinmerac

P244

0.1 µg/l

136

0

<0.009

<0.01719

0

Pesticides Simazine

P073

0.1 µg/l

136

0

<0.011

<0.011

0

Pesticides Tebuconazole

P177

0.1 µg/l

136

0

<0.006

<0.006

0

Pesticides Terbutryn

P077

0.1 µg/l

136

0

<0.009

<0.009

0

Pesticides Triadimefon

P078

0.1 µg/l

136

0

<0.012

<0.012

0

Pesticides Tri-allate

P079

0.1 µg/l

136

0

<0.003

<0.003

0

Pesticides Triclopyr

P131

0.1 µg/l

136

0

<0.011

<0.011

0

Polycyclic Aromatic Hydrocarbons (Total by Calculation)

B011F

0.1 µg/l

1,572

0

0

0.0022262

0

Selenium (Total)

B009

10 µg Se/l

1,572

0

<0.07

1.6381

0

Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

D009B

10 µg/l

1,572

0

0

0.3927

0

Trihalomethanes (Total by Calculation)

D011

100 µg/l

1,572

0

0

65.091

0

Totals

59,155

65

Table 10: Quality of water at consumer’s tap (zones) – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 percentile (representing a minimum)

99 percentile (representing a maximum)

No. of zones failing standard

Aluminium (Total)

A021

200 µg Al/l

6,582

0

<14

19

0

Colour

A001

20 mg/l Pt/Co

7,652

0

<0.7

2.59

0

Iron (Total)

A022

200 µg Fe/l

6,582

13

<8

84

10

Manganese (Total)

A023

50 µg Mn/l

6,582

1

<0.7

5.6

1

Odour

A003

0 Dilution number at 25°C

7,652

4

0

0

3

Sodium (Total)

A009

200 mg Na/l

1,572

1

6.1

94.553

1

Taste (Taste Quant)

A004

0 Dilution number at 25°C

7,652

2

0

0

2

Tetrachloromethane (Total)

D008

3 µg/l

1,572

0

<0.19

<0.2

0

Turbidity

A002

4 NTU

7,652

0

<0.12

0.24

0

Totals

53,498

21

Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Ammonium (Total)

A014

0.5 mg NH4/l

7,652

0

<0.029

<0.064

Chloride

D002A

250 mg Cl/l

136

0

8.944

140.36

Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

6,582

0

0

0

Coliform Bacteria (Indicator)

C001A

0 number/100 ml

21,663

44

0

0

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

7,652

N/A

0

37

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

7,652

0

124.4

780

Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

A006

6.5 – 9.5 pH Value

7,652

1

6.93

8.27

Residual Disinfectant – Free

C009

No abnormal change

21,663

N/A

0.04

0.63

Residual Disinfectant – Total

C010

No abnormal change

864

N/A

0.12

0.7335

Sulphate

A007

250 mg SO4/l

136

0

6.059

123.082

Total Organic Carbon

A017

No abnormal change

136

N/A

<0.8

3.463

Totals

81,788

45

Anglian Water Services Limited – AMP8 Warren Hill PFAS

Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

Reference: ANH-2024-00001

Version Number: 1

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Anglian Water Services Limited, with registered number 02366656 (hereinafter called ‘the Company’).

Assets Affected:

  • Southfields Source CSTH0WV
  • Southfields Bore 3 ASTH3CV
  • Southfields Bore 4 ASTH4CV
  • Southfields WTW TSTHF
  • Warren Hill 1 Reservoir TWH1
  • Newmarket PWSZ ZFS03
  • Cheveley PWSZ ZFE36
  • Bottisham PWSZ ZFE35

Details of this Notice:

  1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a regulation 28(1) report of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated 2 July 2024, which states that there is or has been a significant risk of supplying water from Southfields borehole sources (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
  2. Consequently, this Notice is served on the Company by the Inspectorate on behalf of the Secretary of State, under regulation 28(4) for the assets listed above, for risks associated with:

Description of Risk

Hazard/ Hazardous Event/ Parameter

Hazard I D

Increasing PFAS to Tier 2 target breach.

H067 Per- and polyfluoroalkyl substances (PFAS)

Various including:

Southfields WTW ANH-TSTHF-H067-TR3605

Table 1: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.

  1. The Company are required to satisfy the following requirements.

The date given is that until or by which the requirements must be maintained or satisfied, as appropriate.

Requirements:

(a) To maintain the following measures for the period specified in each case:

  1. Regular review and update of the ground water risk assessments.
    Date: Ongoing for the duration of this Notice
  2. Operational and regulatory monitoring for PFAS at the raw water source, and final water at Southfields WTW and Warren Hill Reservoir No 1.
    Date: Ongoing for the duration of this Notice
  3. Tier 2 sample results on the final water investigated in line with company procedures.
    Date: Ongoing for the duration of this Notice
  4. Understand the PFAS risks from the catchment investigations and continue to understand catchment management opportunities and control measures.
    Date: Ongoing for the duration of this Notice

(b) To review, revise or make operational the following measures, by the dates specified in each case:

  1. The Company will take all reasonable steps to ensure that the PFAS levels do not exceed Tier 3 on the final water and any steps necessary must be taken to protect public health. If the concentration in any water sample exceeds the Tier 3, in water supplied to consumers, reasonable measures will be taken to protect public health in consultation with local health professionals.
    Date: Ongoing for the duration of this Notice
  2. Report any Tier 2 PFAS triggers on the Warren Hill 1 Reservoir or Southfields WTW final water to; DWI, UKHSA and Local Authorities as per the reporting requirements.
    Date: Ongoing for the duration of this Notice
  3. Continually appraise the risk of PFAS as a hazard as part of the Regulation 27 Risk Assessment for the supply systems supplied by Southfields raw water Sources, Southfields WTW treated water and Warren Hill 1 Reservoir final water, according to a Drinking Water Safety Plan approach, and ensure that Regulation 28 documents are regularly reviewed and updates provided as necessary.
    Date: Ongoing for the duration of this Notice
  4. Complete the planning, design and procurement arrangements to provide GAC treatment on the Southfields raw water sources.
    Date: 31 July 2027
  5. Complete construction, installation and commissioning of GAC treatment on the Southfields raw water sources.
    Date: 31 March 2030

(c) To audit whether the measures have been effective by the following means:

  1. Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
    Date: 31 October 2024
  2. Implement, and keep under continuous review, the audit strategy defined in measure (c)1.
    Date: Following completion of measure (c)1. onwards.

(d) Not to supply water for regulation 4(1) purposes from Southfields borehole sources, or not to so supply unless the specified conditions below are satisfied:

  1. Not applicable.

(e) To provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risks:

  1. Provide a progress report annually.
    Date: by 31 January each year.
  2. Provide a report confirming completion of the planning, design and procurement arrangements to provide GAC treatment for the Southfields raw water sources.
    Date: 31 August 2027
  3. Provide a report confirming the completion of construction, installation and commissioning of the GAC treatment at the Southfields raw water sources. Commissioning must include the following to account for the changes made:
    • An appropriate maintenance regime for any installed processes.
    • Full integration of the new (or modified) processes into the site control and monitoring systems.
    • Updating of the Site-Specific Disinfection Policy and any associated site-specific procedures.
    • Updating of the Site Operating Manual and removal of all out-of-date material from circulation.
    • Provisions of adequate training for all relevant personnel on the operation, repair and maintenance of the installed (or modified) process and the revised procedures, policies and manual.
      Date: 30 April 2030
  1. Review the risk assessments for Southfields raw water sources as required by Regulation 27(4).
    Date: 30 April 2030
  2. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 30 November 2024
  3. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  4. Submit a report in the event that any completed measures of this Notice need to be altered in any way, for any reason.
    Date: Ongoing for the duration of this Notice
  5. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 April 2031

Further Details of this Notice:

  1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
  2. Under regulation 28(6) the Inspectorate, on behalf of the Secretary of State, may by notice served on the Company, revoke or vary this Notice.
  3. Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991 (as amended).

Signed

Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
12 August 2024
Reference: ANH-2024-00001

 

The Drinking Water Inspectorate (DWI) was formed in 1990 to provide independent reassurance that water supplies in England and Wales are safe and drinking water quality is acceptable to consumers.

We are a team of 49 staff with specialist knowledge of drinking water quality and supply, regulation, data management, and public health.

Marcus Rink, Chief Inspector

Marcus Rink is the Chief Inspector of Drinking Water, appointed in August 2015. As Chief Inspector he provides independent scrutiny of the water industry ensuring the safety and quality of water and public confidence through a robust regulatory framework. His role encompasses a range of statutory and non-statutory functions, discharging the duties of the Secretary of State for England and the Welsh Government to ensure companies meet their regulatory requirements and local authorities take action in respect of water supplies.

Laura Moss, Deputy Chief Inspector

Laura Moss is currently the Deputy Chief Inspector of Drinking Water Quality for England and Wales. Prior to that she had been a Principal Inspector with the Drinking Water Inspectorate since 2007, regulating drinking water quality in the public water supply industry in England and Wales, and more recently providing technical advice to local authorities carrying out their regulatory duties for private water supplies.

Nicholas Adjei, Deputy Chief Inspector

Nicholas Adjei is currently Deputy Chief Inspector. Nick has more than twenty-five years’ experience in engineering and consultancy. In previous roles Nick has headed up planning, monitoring and evaluation at an international NGO focusing on sustainable community-based projects across the southern hemisphere. He has experience of delivering major flood risk management schemes at the Environment Agency, he has previously been Head of Climate Change and Water Quality at OFWAT, and most recently with that regulator has been focussing on environmental issues and asset resilience in the water industry.

Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

Reference: ANH-2024-00002

Version Number: 1

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Anglian Water Services Limited, with registered number 02366656 (hereinafter called ‘the Company’).

Assets Affected:

  • Barrow Source CBRW0WV

  • Barrow Borehole 1 ABRW1CV

  • Barrow Borehole 2 ABRW2CV

  • Barrow Borehole 3 ABRW3CV

  • Barrow Borehole 4 ABRW4CV

  • Barrow Borehole 6 ABRW6CV

  • Barrow Borehole 7 ABRW7CV

  • Goxhill 1 Source CGOX0WV

  • Goxhill 1 Borehole 3 AGOX3CV

  • Goxhill 1 Borehole 4 AGOX4CV

  • Thornton Source CTHO0WV

  • Thornton Borehole 1 ATHO1CV

  • Thornton Borehole 2 ATHO2CV

  • Thornton Borehole 3 ATHO3CV

  • Barrow WTW TBRW1

  • Barrow PWSZ ZLN04

  • Kirton in Lindsey PWSZ  ZLN76

Details of this Notice:

  1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a regulation 28(1) report of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated 2 July 2024, which states that there is or has been a significant risk of supplying water from Barrow Water Treatment Works (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
  2. Consequently, this Notice is served on the Company by the Inspectorate on behalf of the Secretary of State, under regulation 28(4) for the assets listed above, for risks associated with:

Description of Risk

Hazard/ Hazardous Event/ Parameter

Hazard I D

Increasing PFAS to tier 2 target breach.

H067 Per- and polyfluoroalkyl substances (PFAS)

Various including:

Barrow Source ANH-CBRW0WV-H067-CA0211

Table 1: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.

  1. The Company are required to satisfy the following requirements.

The date given is that until or by which the requirements must be maintained or satisfied, as appropriate.

Requirements:

(a) To maintain the following measures for the period specified in each case:

  1. Regular review and update of the ground water risk assessments.
    Date: Ongoing for the duration of this Notice
  2. Operational and regulatory monitoring for PFAS at the raw water sources, and final water at Barrow WTW.
    Date: Ongoing for the duration of this Notice
  3. Tier 2 sample results on the final water investigated in line with company procedures.
    Date: Ongoing for the duration of this Notice
  4. Understand the PFAS risks from the catchment investigations and continue to understand catchment management opportunities and control measures.
    Date: Ongoing for the duration of this Notice

(b) To review, revise or make operational the following measures, by the dates specified in each case:

  1. The Company will take all reasonable steps to ensure that the PFAS levels do not exceed Tier 3 on the final water and any steps necessary must be taken to protect public health. If the concentration in any water sample exceeds the Tier 3, in water supplied to consumers, reasonable measures will be taken to protect public health in consultation with local health professionals.
    Date: Ongoing for the duration of this Notice
  2. Report any Tier 2 PFAS triggers on the Barrow WTW final water to DWI, UKHSA and Local Authorities as per the reporting requirements.
    Date: Ongoing for the duration of this Notice
  3. Continually appraise the risk of PFAS as a hazard as part of the Regulation 27 Risk Assessment for the supply systems supplied by the Barrow WTW raw water sources and Barrow WTW final water, according to a Drinking Water Safety Plan approach, and ensure that Regulation 28 documents are regularly reviewed and updates provided as necessary.
    Date: Ongoing for the duration of this Notice
  4. Complete the planning, design and procurement arrangements to provide GAC treatment on the raw water sources supplying Barrow WTW.
    Date: 31 August 2027
  5. Complete the construction, installation and commissioning of GAC treatment on the raw water sources supplying Barrow WTW.
    Date: 31 March 2030

(c) To audit whether the measures have been effective by the following means:

  1. Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
    Date: 31 October 2024
  2. Implement, and keep under continuous review, the audit strategy defined in measure (c)1.
    Date: Following completion of measure (c)1. onwards.

(d) Not to supply water for regulation 4(1) purposes from Barrow Water Treatment Works, or not to so supply unless the specified conditions below are satisfied:

  1. Not applicable.

(e) To provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risks:

  1. Provide a progress report annually.
    Date: by 31 January each year.
  2. Provide a report confirming the completion of the planning, design and procurement arrangements to provide GAC treatment on the raw water sources supplying Barrow WTW.
    Date: 30 September 2027
  3. Provide a report confirming the completion of construction, installation and commissioning of the GAC treatment on the raw water sources supplying Barrow WTW. Commissioning must include the following to account for the changes made:
    • An appropriate maintenance regime for any installed processes.
    • Full integration of the new (or modified) processes into the site control and monitoring systems.
    • Updating of the Site-Specific Disinfection Policy and any associated site-specific procedures.
    • Updating of the Site Operating Manual and removal of all out-of-date material from circulation.
    • Provisions of adequate training for all relevant personnel on the operation, repair and maintenance of the installed (or modified) process and the revised procedures, policies and manual.
      Date: 30 April 2030
  1. Review the risk assessments for Barrow Water Treatment Works raw water sources as required by Regulation 27(4).
    Date: 30 April 2030
  2. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 30 November 2024
  3. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  4. Submit a report in the event that any completed measures of this Notice need to be altered in any way, for any reason.
    Date: Ongoing for the duration of this Notice
  5. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 April 2031

Further Details of this Notice:

  1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
  2. Under regulation 28(6) the Inspectorate, on behalf of the Secretary of State, may by notice served on the Company, revoke or vary this Notice.
  3. Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991 (as amended).

Signed

Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
12 August 2024
Reference: ANH-2024-00002

 

South East Water Limited – Cornish Treatment Works Disinfection Risks

Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

Reference: SEW-2024-00002

Version Number: 1

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): South East Water Limited, with registered number 02679874 (hereinafter called ‘the Company’).

Assets Affected:

  • T023 – Cornish Treatment Works

Details of this Notice:

  1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a regulation 28(1) report of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated 1 January 2024, which states that there is or has been a significant risk of supplying water from Cornish Treatment Works (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
  2. Consequently, this Notice is served on the Company by the Inspectorate on behalf of the Secretary of State, under regulation 28(4) for the assets listed above, for risks associated with:

Description of Risk

Hazard/ Hazardous Event/ Parameter

Hazard I D

Inadequately disinfected water

Escherichia coli (E. coli)

T023-TREATMENT-C002

Inadequately disinfected water

Coliform bacteria

T023-TREATMENT-C001

Inadequately disinfected water

Enterococci

T023-TREATMENT-C003

Table 1: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.
  1. The Company are required to satisfy the following requirements.

The date given is that until or by which the requirements must be maintained or satisfied, as appropriate.

Requirements:

(a) To maintain the following measures for the period specified in each case:

  1. Optimisation of all existing treatment processes.
    Date: Ongoing for the duration of this Notice
  2. Operation of all processes within defined normal operating ranges with appropriate triggers, responses and contingency procedures.
    Date: Ongoing for the duration of this Notice
  3. Online turbidity and chlorine monitoring with appropriate alarms and failsafe shutdown.
    Date: Ongoing for the duration of this Notice
  4. Enhanced and large volume operational monitoring for microbiological parameters at Cornish Treatment Works.
    Date: Ongoing for the duration of this Notice

(b) To review, revise or make operational the following measures, by the dates specified in each case:

  1. Complete optioneering review to confirm a programme of work to provide adequate disinfection under all circumstances and flow rates.
    Date: 30 September 2024
  2. Complete the detailed design of the preferred solution identified in measure (b)1 above.
    Date: 31 March 2025
  3. Complete the construction, installation and commissioning of the chosen disinfection system as defined by measures (b)1 and (b)2. Commissioning must include the following to account for the changes made:
  4. An appropriate maintenance regime for any installed processes;
  5. Full integration of the new processes into the site control and monitoring systems;
  6. Updating of the Site-Specific Disinfection Policy and any associated site-specific procedures;
  7. Updating of the Site Operating Manual and removal of all out-of-date material from circulation; and
  8. Provisions of adequate training for all relevant personnel on the operation, repair and maintenance of the installed process and the revised procedures, policies and manual.
    Date: 31 March 2027

(c) To audit whether the measures have been effective by the following means:

  1. Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
    Date: 31 August 2024
  2. Implement, and keep under continuous review, the audit strategy defined in measure (c)1.
    Date: Following completion of measure (c)1 onwards.

(d) Not to supply water for regulation 4(1) purposes from Cornish Treatment Works, or not to so supply unless the specified conditions below are satisfied:

  1. Not applicable.

(e) To provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risks:

  1. Provide a progress report annually.
    Date: by 31 January each year
  2. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 30 September 2024
  3. Report on the output of the optioneering review as detailed in measure (b)1.

Date: 31 October 2024

  1. Report on the detailed design of the preferred solution a detailed in measure (b)2.

Date: 30 April 2025

  1. Confirm the completion of installation and commissioning of the chosen disinfection system along with an updated SSDP, SOP and evidence of training for all relevant operators as detailed in measure (b)3.

Date: 30 April 2027

  1. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  2. Submit a report in the event that any completed measures of this Notice need to be altered in any way, for any reason.
    Date: Ongoing for the duration of this Notice
  3. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 April 2028

Further Details of this Notice:

  1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
  2. Under regulation 28(6) the Inspectorate, on behalf of the Secretary of State, may by notice served on the Company, revoke or vary this Notice.
  3. Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991 (as amended).

Signed

Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
26 June 2024
Reference: SEW-2024-00002

TMS (Thames Water Utilities Ltd)

Report Data Range: For the whole year 2021

Table 1: Quality of water leaving service treatment works – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

Nitrite (Total)

A013B

0.1 mg NO2/l

4,285

0

<0.0018

0.011542

0

Totals

4,285

0

Table 2: Quality of water leaving service treatment works – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

17,595

0

0

0

0

Total Coliforms (Confirmed)

C001

0 number/100 ml

17,595

6

0

0

6

Totals

35,190

6

Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

17,590

N/A

0

6

Residual Disinfectant – Total

C010

No abnormal change

17,618

N/A

0.37

1.02

Turbidity – Indicator

A002A

1 NTU

17,596

4

<0.12

<0.17

Totals

52,804

4

Table 4: Quality of water leaving service reservoirs – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of reservoirs failing standard

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

19,216

1

0

0

1

Total Coliforms (Confirmed)

C001

0 number/100 ml

19,217

5

0

0

0

Totals

38,433

6

Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

19,210

N/A

0

24

Residual Disinfectant – Total

C010

No abnormal change

19,238

N/A

0.14

0.79

Totals

38,448

0

Table 6: Quality of water leaving bulk supply points – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of supply point with failures

Bromate

F003

10 µg BrO3/l

711

0

<0.8

3.464

0

Cyanide (Total)

B003

50 µg CN/l

710

0

<1

4.423

0

Mercury (Total)

B005

1 µg Hg/l 

714

0

<0.07

<0.07

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

737

0

0

0.076

0

Pesticides 2 4-D

P020

0.1 µg/l

712

0

<0.017

<0.017

0

Pesticides 2 4-DB

P082

0.1 µg/l

712

0

<0.016

<0.016

0

Pesticides Atrazine

P004

0.1 µg/l

715

0

<0.005

0.036

0

Pesticides Bentazone

P006

0.1 µg/l

712

0

<0.012

<0.012

0

Pesticides Bromoxynil

P008

0.1 µg/l

712

0

<0.019

<0.019

0

Pesticides Carbendazim (Total)

P150

0.1 µg/l

715

0

<0.02

<0.02

0

Pesticides Carbetamide 

P010

0.1 µg/l

715

0

<0.005

<0.007

0

Pesticides Chlortoluron

P014

0.1 µg/l

715

0

<0.004

<0.006

0

Pesticides Clopyralid

P018

0.1 µg/l

712

0

<0.022

<0.022

0

Pesticides Dicamba

P025

0.1 µg/l

712

0

<0.022

<0.022

0

Pesticides Dichlorprop

P026

0.1 µg/l

712

0

<0.012

<0.012

0

Pesticides Diuron

P032

0.1 µg/l

715

0

<0.005

0.02084

0

Pesticides Flufenacet

P230

0.1 µg/l

179

0

<0.004

0.01

0

Pesticides Fluroxypyr

P040

0.1 µg/l

712

0

<0.015

<0.015

0

Pesticides Isoproturon

P048

0.1 µg/l

715

0

<0.004

<0.005

0

Pesticides Linuron

P051

0.1 µg/l

715

0

<0.004

<0.006

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

712

0

<0.02

<0.02

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

712

0

<0.014

<0.014

0

Pesticides Metaldehyde

P226

0.1 µg/l 

714

0

<0.014

0.01885

0

Pesticides Metazachlor

P203

0.1 µg/l 

187

0

<0.005

0.00624

0

Pesticides Monuron

P113

0.1 µg/l

715

0

<0.005

<0.006

0

Pesticides Pentachlorophenol

P060

0.1 µg/l

712

0

<0.008

<0.008

0

Pesticides Picloram (Total)

P122

0.1 µg/l

712

0

<0.021

<0.021

0

Pesticides Propyzamide

P071

0.1 µg/l

715

0

<0.005

0.01284

0

Pesticides Quinmerac

P224

0.1 µg/l

189

0

<0.005

0.01284

0

Pesticides Simazine

P073

0.1 µg/l

715

0

<0.009

0.02152

0

Pesticides Triclopyr

P131

0.1 µg/l

712

0

<0.016

<0.016

0

Radon

F031

100 Bq/l

8

0

1.5

2.1

0

Totals

20,555

0

Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Clostridium Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

722

0

0

0

Gross Alpha

F004

0.1 Bq/l

202

1

<0.05

0.08

Gross Beta

F005

1 Bq/l

202

0

<0.05

0.2097

Total Organic Carbon

A017

No abnormal change

712

N/A

<0.6

3.1

Tritium

F006

100 Bq/l

15

0

<5.6

7.58

Totals

1,853

1

Table 9: Quality of water at consumer’s tap (zones) – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of zones failing standard

1 2-Dichloroethane (Total)

F001

3 µg/l

1980

0

<0.1

<0.1

0

Antimony

B008A

5 µg Sb/l

1,993

0

<0.3

0.5

0

Arsenic (Total)

B001A

10 µg As/l

1,993

0

<0.3

1.4

0

Benzene (Total)

F002

1 µg/l

1980

0

<0.1

<0.1

0

Benzo[a]Pyrene (Total)

D007

0.01 µg/l

2,035

0

<0.002

<0.002

0

Boron

D005A

1 mg B/l

1,994

0

0.014

0.088

0

Bromate

F003

10 µg BrO3/l

131

0

<0.8

4.236

0

Cadmium (Total)

B002

5 µg Cd/l

1,994

0

<0.2

<0.4

0

Chromium (Total)

B004

50 µg Cr/l

1,994

0

<2

<2

0

Copper (Total)

A024A

2 mg Cu/l

1,971

1

<0.004

0.5934

1

Cyanide (Total)

B003

50 µg CN/l

9

0

<1

<1

0

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

25,769

1

0

0

1

Enterococci (Confirmed)

C003

0 number/100 ml

1,977

1

0

0

1

Fluoride (Total)

A027

1.5 mg F/l

1,975

0

0.06476

0.44824

0

Lead (10 – will apply 25.12.2013)

B007B

10 µg Pb/l

1,976

5

<0.4

6.223

5

Mercury (Total)

B005

1 µg Hg/l 

9

0

<0.07

<0.07

0

Nickel (Total) 

B006A 

20 µg Ni/l

1,972

4

<1.3

7.216

4

Nitrate (Total)

A012

50 mg NO3/l

7,265

0

6.704

37.0302

0

Nitrite – Consumer’s Taps

A013A

0.5 mg NO2/l

7,265

0

<0.0018

0.239836

0

Nitrite/Nitrate formula

A013C

1 mg/l

7,264

0

0.1895

0.75

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

10

0

0

0.079

0

Pesticides 2 4-D

P020

0.1 µg/l

10

0

<0.017

<0.017

0

Pesticides 2 4-DB

P082

0.1 µg/l

10

0

<0.016

<0.016

0

Pesticides Atrazine

P004

0.1 µg/l

10

0

<0.005

<0.006

0

Pesticides Bentazone

P006

0.1 µg/l

10

0

<0.012

<0.012

0

Pesticides Bromoxynil

P008

0.1 µg/l

10

0

<0.019

<0.019

0

Pesticides Carbendazim (Total)

P150

0.1 µg/l

10

0

<0.02

<0.02

0

Pesticides Carbetamide 

P010

0.1 µg/l

10

0

<0.005

<0.007

0

Pesticides Chlortoluron

P014

0.1 µg/l

10

0

<0.004

<0.006

0

Pesticides Clopyralid

P018

0.1 µg/l

10

0

<0.022

<0.022

0

Pesticides Dicamba

P025

0.1 µg/l

10

0

<0.022

<0.022

0

Pesticides Dichlorprop

P026

0.1 µg/l

10

0

<0.012

<0.012

0

Pesticides Diuron

P032

0.1 µg/l

10

0

<0.005

<0.006

0

Pesticides Flufenacet

P230

0.1 µg/l

10

0

<0.004

0.007

0

Pesticides Fluroxypyr

P040

0.1 µg/l

10

0

<0.015

<0.015

0

Pesticides Isoproturon

P048

0.1 µg/l

10

0

<0.004

<0.005

0

Pesticides Linuron

P051

0.1 µg/l

10

0

<0.005

<0.006

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

10

0

<0.02

<0.02

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

10

0

<0.014

<0.014

0

Pesticides Metaldehyde

P226

0.1 µg/l 

10

0

<0.014

0.049

0

Pesticides Metazachlor

P203

0.1 µg/l 

10

0

<0.005

<0.006

0

Pesticides Monuron

P113

0.1 µg/l

10

0

<0.005

<0.006

0

Pesticides Pentachlorophenol

P060

0.1 µg/l

10

0

<0.008

<0.008

0

Pesticides Picloram (Total)

P122

0.1 µg/l

10

0

<0.021

<0.021

0

Pesticides Propyzamide

P071

0.1 µg/l

10

0

<0.005

0.018

0

Pesticides Quinmerac

P244

0.1 µg/l

10

0

<0.005

<0.017

0

Pesticides Simazine

P073

0.1 µg/l

10

0

<0.009

<0.009

0

Pesticides Triclopyr

P131

0.1 µg/l

10

0

<0.016

<0.016

0

Polycyclic Aromatic Hydrocarbons (Total by Calculation)

B011F

0.1 µg/l

2,005

0

0

0.003

0

Selenium (Total)

B009

10 µg Se/l

1,993

0

<0.4

2.7

0

Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

D009B

10 µg/l

1,980

0

0

1.4

0

Trihalomethanes (Total by Calculation)

D011

100 µg/l

1,980

0

0.9

31.338

0

Totals

81,784

12

Table 10: Quality of water at consumer’s tap (zones) – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 percentile (representing a minimum)

99 percentile (representing a maximum)

No. of zones failing standard

Aluminium (Total)

A021

200 µg Al/l

8,624

0

<10.5

19.5

0

Colour

A001

20 mg/l Pt/Co

9,166

0

<2

<2.66

0

Iron (Total)

A022

200 µg Fe/l

8,960

5

<3

40.517

5

Manganese (Total)

A023

50 µg Mn/l

8,624

0

<0.4

2.6

0

Odour

A003

0 Dilution number at 25°C

9,178

0

0

0

0

Sodium (Total)

A009

200 mg Na/l

1,995

0

6.4

41.104

0

Taste (Taste Quant)

A004

0 Dilution number at 25°C

9,174

2

0

0

2

Tetrachloromethane (Total)

D008

3 µg/l

1,980

0

<0.1

0.2

0

Turbidity

A002

4 NTU

9,176

0

<0.12

0.21

0

Totals

66,877

7

Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Ammonium (Total)

A014

0.5 mg NH4/l

7,276

0

<0.01

0.23

Chloride

D002A

250 mg Cl/l

1,996

0

13.1591

60.6336

Clostridium Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

9

0

0

0

Coliform Bacteria (Indicator)

C001A

0 number/100 ml

25,769

59

0

0

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

9,170

N/A

0

50

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

9,187

0

396.4

742.12

Gross Alpha

F004

0.1 Bq/l

9

0

<0.05

0.1

Gross Beta

F005

1 Bq/l

9

0

0.05

0.23

Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

A006

6.5 – 9.5 pH Value

9,177

0

7.1

8

Residual Disinfectant – Total

C010

No abnormal change

25,819

N/A

0.16

0.91

Sulphate

A007

250 mg SO4/l

1,996

0

10.1785

76.9503

Total Organic Carbon

A017

No abnormal change

9

N/A

<0.6

6.3

Totals

90,426

59

Drinking Water Inspectorate Complaints Procedure

Owner: Business Performance Manager

Review: Annually

Last reviewed: December 2024

Stage 1

Complaints about the Inspectorate should be made to the Chief Inspector detailing the nature of the complaint. In the first instance all complaints will be investigated by the Chief Inspector or a Deputy Chief Inspector.

A response to the complaint will be made within 20 working days of the date it is received by the Inspectorate. The response will include details of what action has been taken. If it is not possible to make a response within 20 working days because of the need for further information or investigation an interim response will be made. The address for such complaints is:

Chief Inspector of Drinking Water
Drinking Water Inspectorate
Ground Floor, SW
Seacole Building
2 Marsham Street
London
SW1P 4DF

Or dwi.enquiries@defra.gov.uk

Stage 2

If the complainant is not satisfied, the complainant can seek a review by the Director, Floods and Water in Defra, who will, if the matter is scientific or technical, appoint an independent specialist to advise them, if necessary.

The address for such complaints is:

Director, Floods and Water
Floods and Water Directorate
Defra
Seacole Building
2 Marsham Street
London
SW1P 4DF

If the complaint concerns the Inspectorate’s actions in Wales, the second stage review would be carried out by the Director, Climate Change and Environmental Sustainability of the Welsh Government, with appropriate specialist advice as necessary.

Director, Climate Change and Environmental Sustainability
Welsh Government
Cathays Park 2
Cathays Park
Cardiff
CF10 3NQ

South East Water Limited – Boughton Water Treatment Works – Nitrate

Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

Reference: SEW-2023-00011

Version Number: 1

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): South East Water Limited, with registered number 02679874 (hereinafter called ‘the Company’).

Assets Affected:

Asset Name

Reference

Boughton Supply System

Y306T01 

Table 1: List of assets affected and associated reference numbers

Details of this Notice:

  1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a regulation 28(1) report of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated 30 November 2023, which states that there is or has been a significant risk of supplying water from Boughton WTW (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
  2. Consequently, this Notice is served on the Company by the Inspectorate on behalf of the Secretary of State, under regulation 28(4) for the assets listed above, for risks associated with:

Description of Risk

Hazard/ Hazardous Event/ Parameter

Hazard I D

Potential risks to drinking water quality and non-compliance with the Water Supply (Water Quality) Regulations. 

Nitrate

T306T01-TREATMENT-A012 

R527T01-STORAGE-A012 

R527T02-STORAGE-A012 

R581T01-STORAGE-A012 

R581T02-STORAGE-A012 

R581T03-STORAGE-A012 

R560T01-STORAGE-A012 

T560T02-STORAGE-A012 

Z311-DISTRIBUTION-A012 

Z320-DISTRIBUTION-A012

Table 2: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.
  1. The Company are required to satisfy the following requirements.

The date given is that until or by which the requirements must be maintained or satisfied, as appropriate.

Requirements:

(a) To maintain the following measures for the period specified in each case:

  1. Weekly water sampling of raw and final waters for nitrate. 
    Date: Ongoing for the duration of this Notice
  2. Continuation of catchment management working with stakeholders to reduce input from sources, understand activities contributing to nitrate in catchment and put in place and maintain appropriate mitigations for areas at high risk. 
    Date: Ongoing for the duration of this Notice

(b) To review, revise or make operational the following measures, by the dates specified in each case:

  1. Install online nitrate monitors on all raw water sources.
    Date: 31 March 2026
  2. Plan and design the option to mitigate risk of nitrate Boughton Treatment Works. 
    Date: 31 March 2027
  3. Install and commission treatment at Boughton Treatment Works to mitigate the risk of nitrate. Commissioning must include the following to allow for the changes made: 
  4. An appropriate maintenance regime for nitrate treatment; 
  5. Full integration of the new processes into the site control and monitoring systems; 
  6. Updating of the Site Specific Disinfection Policy and any associated site-specific procedures;
  7. Updating of Site Operating Manual and removal of all out of date material from circulation; and 
  8. Provide adequate training to operators as part of the commissioning process and for any revision of the Site Operating Manual completed under (b)2. 

Date: 31 March 2029

(c) To audit whether the measures have been effective by the following means:

  1. Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
    Date: 31 March 2024
  2. Implement, and keep under continuous review, the audit strategy defined in measure (c)1.
    Date: Following completion of measure (c)1. onwards.

(d) Not to supply water for regulation 4(1) purposes from Barcombe Storage, or not to so supply unless the specified conditions below are satisfied:

  1. Not applicable.

(e) To provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risks:

  1. Provide a progress report annually.
    Date: by 31 January each year.
  2. Confirm installation of nitrate monitors on all raw water sources.
    Date: 30 April 2026
  3. Submit a report outlining the chosen solution designed under (b)2. 
    Date: 30 April 2027
  4. Submit a report on completion of the commissioning or modification of the chosen treatment option (measure (b)2), with an updated site-specific Disinfection Policy, an updated site operating manual and evidence of completion of training required.
    Date: 30 April 2029
  5. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1. 
    Date: 31 March 2024
  6. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  7. Submit a report in the event that any completed measures of this Notice need to be altered in any way, for any reason.
    Date: Ongoing for the duration of this Notice
  8. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 April 2030

Further Details of this Notice:

  1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
  2. Under regulation 28(6) the Inspectorate, on behalf of the Secretary of State, may by notice served on the Company, revoke or vary this Notice.
  3. Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991 (as amended).

Signed

Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
5 January 2024
Reference: SEW-2023-00011

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VWP (Veolia Water Projects Ltd)

Report Data Range: For the whole year 2021

Table 1: Quality of water leaving service treatment works – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

Nitrite (Total)

A013B

0.1 mg NO2/l

16

0

<0.007

<0.007

0

Totals

16

0

Table 2: Quality of water leaving service treatment works – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

156

0

0

0

0

Total Coliforms (Confirmed)

C001

0 number/100 ml

156

0

0

0

0

Totals

312

0

Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

156

N/A

0

5

Residual Disinfectant – Total

C010

No abnormal change

156

N/A

0.5757

0.8329

Turbidity – Indicator

A002A

1 NTU

155

0

<0.1

0.34

Totals

467

0

Table 4: Quality of water leaving service reservoirs – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of reservoirs failing standard

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

312

0

0

0

0

Total Coliforms (Confirmed)

C001

0 number/100 ml

312

0

0

0

0

Totals:

624

0

Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

312

N/A

0

18

Residual Disinfectant – Total

C010

No abnormal change

312

N/A

0.4013

0.69

Totals:

624

0

Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Gross Alpha

F004

0.1 Bq/l

16

0

<0.018

<0.034

Gross Beta

F005

1 Bq/l

16

0

<0.016

0.045

Tritium

F006

100 Bq/l

16

0

<5

7.2

Totals

48

0

Table 9: Quality of water at consumer’s tap (zones) – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of zones failing standard

1 2-Dichloroethane (Total)

F001

3 µg/l

6

0

<0.09

<0.14

0

Antimony

B008A

5 µg Sb/l

9

0

<0.2

<0.2

0

Arsenic (Total)

B001A

10 µg As/l

9

0

<1

<1

0

Benzene (Total)

F002

1 µg/l

6

0

<0.03

<0.07

0

Benzo[a]Pyrene (Total)

D007

0.01 µg/l

8

0

<0.0018

<0.0018

0

Boron

D005A

1 mg B/l

9

0

<0.1

<0.1

0

Bromate

F003

10 µg BrO3/l

8

0

<0.3

<0.3

0

Cadmium (Total)

B002

5 µg Cd/l

9

0

<0.2

<0.2

0

Chromium (Total)

B004

50 µg Cr/l

9

0

<0.5

<0.5

0

Copper (Total)

A024A

2 mg Cu/l

8

0

<0.019

0.047

0

Cyanide (Total)

B003

50 µg CN/l

8

0

<2.7

<2.7

0

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

36

0

0

0

0

Enterococci (Confirmed)

C003

0 number/100 ml

8

0

0

0

0

Fluoride (Total)

A027

1.5 mg F/l

8

0

0.045

0.062

0

Lead (10 – will apply 25.12.2013)

B007B

10 µg Pb/l

8

0

<1

<1

0

Mercury (Total)

B005

1 µg Hg/l 

9

0

<0.1

<0.1

0

Nickel (Total) 

B006A 

20 µg Ni/l

8

0

<2

<2

0

Nitrate (Total)

A012

50 mg NO3/l

8

0

15.3

30.6

0

Nitrite – Consumer’s Taps

A013A

0.5 mg NO2/l

8

0

<0.007

<0.007

0

Nitrite/Nitrate formula

A013C

1 mg/l

8

0

<0.306

<0.612

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

8

0

0

0.026

0

Pesticides Atrazine

P004

0.1 µg/l

8

0

<0.013

<0.016

0

Pesticides Desethylatrazine

P182

0.1 µg/l

8

0

<0.008

<0.015

0

Polycyclic Aromatic Hydrocarbons (Total by Calculation)

B011F

0.1 µg/l

8

0

0

0.0083

0

Selenium (Total)

B009

10 µg Se/l

9

0

<1

<1

0

Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

D009B

10 µg/l

6

0

0

0.1

0

Trihalomethanes (Total by Calculation)

D011

100 µg/l

6

0

3.78

8.8

0

Totals

243

0

Table 10: Quality of water at consumer’s tap (zones) – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 percentile (representing a minimum)

99 percentile (representing a maximum)

No. of zones failing standard

Aluminium (Total)

A021

200 µg Al/l

9

0

<5

<5

0

Colour

A001

20 mg/l Pt/Co

24

0

<2.5

<2.5

0

Iron (Total)

A022

200 µg Fe/l

9

0

<15

<15

0

Manganese (Total)

A023

50 µg Mn/l

9

0

<1

<1

0

Odour

A003

0 Dilution number at 25°C

24

0

0

0

0

Sodium (Total)

A009

200 mg Na/l

9

0

5.66

10

0

Taste (Taste Quant)

A004

0 Dilution number at 25°C

24

0

0

0

0

Tetrachloromethane (Total)

D008

3 µg/l

6

0

<0.11

<0.16

0

Turbidity

A002

4 NTU

24

0

<0.1

0.27

0

Totals

138

0

Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Ammonium (Total)

A014

0.5 mg NH4/l

8

0

<0.05

<0.05

Chloride

D002A

250 mg Cl/l

8

0

13

22

Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

8

0

0

0

Coliform Bacteria (Indicator)

C001A

0 number/100 ml

36

0

0

0

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

24

N/A

0

10

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

24

0

386

548

Gross Alpha

F004

0.1 Bq/l

14

0

<0.018

<0.034

Gross Beta

F005

1 Bq/l

14

0

<0.016

0.045

Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

A006

6.5 – 9.5 pH Value

24

0

7.1

7.5

Residual Disinfectant – Total

C010

No abnormal change

36

N/A

0.32

0.57

Sulphate

A007

250 mg SO4/l

8

0

<11

19

Total Organic Carbon

A017

No abnormal change

7

N/A

0.5

0.7

Tritium

F006

100 Bq/l

14

0

<5

<5

Totals

225

0

Whistleblowing

The Drinking Water Inspectorate welcomes information from whistleblowers who may wish to report concerns relating to wrongdoing in relation to the quality and sufficiency of water supply and the security of network and information systems in the drinking water supply sector in England and Wales. 

Whistleblowers do not have to be directly employed by the water company, they could be agency staff or contractors and those not yet employed but undergoing training. 

Protections for Whistleblowers

The Chief Inspector of Drinking Water and Inspectors appointed under section 86(1) of the Water Industry Act 1991 are ‘prescribed persons’ under the Prescribed Persons Order 2014 as amended (the Order).  

In general terms, the effect of the Order is that persons passing on information concerning wrongdoing (referred to as “whistleblowing”) should not suffer detriment or victimisation from their employers. 

Any person making a qualifying disclosure to us will receive the protections afforded under the Order and the Employment Rights Act 1996. 

We treat all disclosures made by whistleblowers sensitively and seriously. We follow up each disclosure with an appropriate investigation. We will protect the identity of an individual making an allegation wherever possible. However, in certain circumstances we may be required to reveal the identity, if required by law.  

To get in touch with the Inspectorate you can contact us by phone or email: 

0330 041 6501 or dwi.enquiries@defra.gov.uk 

South East Water Limited – Poverty Bottom Water Treatment Works – Nitrate

Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

Reference: SEW-2023-00012

Version Number: 1

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): South East Water Limited, with registered number 02679874 (hereinafter called ‘the Company’).

Assets Affected:

Asset Name

Reference

Poverty Bottom No.4 Supply System 

Y014

Poverty Bottom No.6 Supply System

Y015

Table 1: List of assets affected and associated reference numbers

Details of this Notice:

  1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a regulation 28(1) report of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated 30 November 2023, which states that there is or has been a significant risk of supplying water from Poverty Bottom WTW (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
  2. Consequently, this Notice is served on the Company by the Inspectorate on behalf of the Secretary of State, under regulation 28(4) for the assets listed above, for risks associated with:

Description of Risk

Hazard/ Hazardous Event/ Parameter

Hazard I D

Potential risks to drinking water quality and non-compliance with the Water Supply (Water Quality) Regulations. 

Nitrate

T014-TREATMENT-A012 

T015-TREATMENT-A012 

R065-STORAGE-A012 

R066-STORAGE-A012 

R068-STORAGE-A012 

R069-STORAGE-A012 

R070-STORAGE-A012 

R071-STORAGE-A012 

R092-STORAGE-A012 

R093-STORAGE-A012 

R010-STORAGE-A012 

R011-STORAGE-A012 

R038-STORAGE-A012 

R005-STORAGE-A012 

Z007-DISTRIBUTION-A012 

Z037-DISTRIBUTION-A012 

Z020-DISTRIBUTION-A012 

Z047-DISTRIBUTION-A012 

Z049-DISTRIBUTION-A012

Table 2: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.
  1. The Company are required to satisfy the following requirements.

The date given is that until or by which the requirements must be maintained or satisfied, as appropriate.

Requirements:

(a) To maintain the following measures for the period specified in each case:

  1. Weekly water sampling of raw and final waters for nitrate. 
    Date: Ongoing for the duration of this Notice
  2. Continuation of catchment management working with stakeholders to reduce input from sources, understand activities contributing to nitrate in catchment and put in place and maintain appropriate mitigations for areas at high risk. 
    Date: Ongoing for the duration of this Notice

(b) To review, revise or make operational the following measures, by the dates specified in each case:

  1. Plan and design the option to mitigate risk of nitrate at Poverty Bottom No.4 and No.6 Treatment Works. 
    Date: 31 March 2027
  2. Install and commission treatment at Poverty No.4 and No.6 Treatment Works to mitigate the risk of nitrate. Commissioning must include the following to allow for the changes made: 
  3. An appropriate maintenance regime for nitrate treatment; 
  4. Full integration of the new processes into the site control and monitoring systems; 
  5. Updating of the Site Specific Disinfection Policy and any associated site-specific procedures;
  6. Updating of Site Operating Manual and removal of all out of date material from circulation; and 
  7. Provide adequate training to operators as part of the commissioning process and for any revision of the Site Operating Manual completed under (b)2. 

Date: 31 March 2028

(c) To audit whether the measures have been effective by the following means:

  1. Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
    Date: 31 March 2024
  2. Implement, and keep under continuous review, the audit strategy defined in measure (c)1.
    Date: Following completion of measure (c)1. onwards.

(d) Not to supply water for regulation 4(1) purposes from Barcombe Storage, or not to so supply unless the specified conditions below are satisfied:

  1. Not applicable.

(e) To provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risks:

  1. Provide a progress report annually.
    Date: by 31 January each year.
  2. Submit a report outlining the chosen solution designed under (b)1. 
    Date: 30 April 2027
  3. Submit a report on completion of the commissioning or modification of the chosen treatment option (measure (b)2), with an updated site-specific Disinfection Policy, an updated site operating manual and evidence of completion of training required. 
    Date: 30 April 2028
  4. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 30 April 2024
  5. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  6. Submit a report in the event that any completed measures of this Notice need to be altered in any way, for any reason.
    Date: Ongoing for the duration of this Notice
  7. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 April 2029

Further Details of this Notice:

  1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
  2. Under regulation 28(6) the Inspectorate, on behalf of the Secretary of State, may by notice served on the Company, revoke or vary this Notice.
  3. Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991 (as amended).

Signed

Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
5 January 2024
Reference: SEW-2023-00012

South West Water Limited – St Agnes Water Quality Improvements

Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

Reference: ISC-2021-00006

Version Number: 6

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): South West Water Limited, with registered number 02366665 (hereinafter called ‘the Company’).

Assets Affected:

  • St Agnes Supply System YIOS4
  • Plump WTW T0001F
  • Tommy’s WTW T0002F

Details of this Notice:

  1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a regulation 28(1) report of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated 09 April 2021, which states that there is or has been a significant risk of supplying water from water treatment works (and associated assets as applicable) on St Agnes Island that could constitute a potential danger to human health or could be unwholesome.
  2. Consequently, this Notice is served on the Company by the Inspectorate on behalf of the Secretary of State, under regulation 28(4) for the assets listed above, for risks associated with:

Description of Risk


Hazard/ Hazardous Event/ Parameter

Potential risks to drinking water quality and non-compliance with the Water Supply (Water Quality) Regulations.



A001 – Colour


A002 – Turbidity


A004 – Taste


A006 – pH


A009 – Sodium


A012 – Nitrate


A017 – TOC


A017A – DOC


A021 – Aluminium


B001A – Arsenic


C001 – Total coliforms


C002 – E. coli


C003 – Enterococci


C004A – C. perfringens


C111 – Cryptosporidium


D002A – Chloride


D011 – THM


F004 – Gross Alpha


F005 – Gross Beta


F007 – Indicative Dose


F031 – Radon


H067 – PFAS

Table 1: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.

  1. The Company are required to satisfy the following requirements.

The date given is that until or by which the requirements must be maintained or satisfied, as appropriate.

Requirements:

(a) To maintain the following measures for the period specified in each case:

  1. Continue the current investigational water quality monitoring programme to support regulation 27 risk assessment and verify the current operational practice and performance.
    Date: Ongoing for the duration of this Notice
  2. Continue to operate the existing assets and supply systems in accordance with operating procedures.
    Date: Ongoing for the duration of this Notice
  3. Maintain current advice to consumers that water supplied to this supply zone should not be used in infant feed and formulas, until such time that the treatment process is capable of reducing the concentration of chloride to below that of the prescribed concentration set out in the Regulations.
    Date: Ongoing for the duration of this Notice
  4. Maintain contingency plans to protect human health in the event of a risk associated with drinking water quality.
    Date: Ongoing for the duration of this Notice

(b) To review, revise or make operational the following measures, by the dates specified in each case:

  1. Investigate the raw water quality and existing treatment processes available on St Agnes to confirm the risks and parameters that are currently unmitigated or require further mitigation to be included in this Notice.
    Date: Complete
  2. Identify and implement short term mitigation(s) as soon as reasonably practicable, based on suitable risk assessment where any hazards that have the potential to contribute to regulation 4 breaches are identified through the completion of measure (b)1.
    Date: Complete
  3. Following the completion of step (b)1, review the existing treatment processes and control measures on St Agnes Island to ascertain if current treatment is capable of the removal of the parameters listed in Section 2 of this Notice.
    Date: Complete
  4. Following the review in step (b)3., if the existing treatment and control measures are not capable of mitigating the risks associated with the hazards listed in section 2 of this notice, design additional treatment stages and control measures required for effective mitigation of the risks associated with these listed hazards.
    Date: Complete
  5. Review and update the regulatory sampling facilities on the island to be in line with the company standard.
    Date: 31 December 2024
  6. Complete the installation and commissioning of the required control measures identified in (b)4., to enable full operational use of the improved supply system.
    Date: 31 March 2025
  7. Update the site policies and procedures to reflect the changes made to the supply system, including providing any relevant additional training to staff, based on the changes made.
    Date: 31 March 2025

(c) To audit whether the measures have been effective by the following means:

  1. Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
    Date: Complete
  2. Implement, and keep under continuous review, the audit strategy defined in measure (c)1.
    Date: Following completion of measure (c)1. onwards.

(d) Not to supply water for regulation 4(1) purposes from water treatment works and associated assets on St Agnes Island, or not to so supply unless the specified conditions below are satisfied:

  1. Not applicable

(e) To provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risks:

  1. Provide a progress report annually.
    Date: by 31 January each year.
  2. Confirm completion of the investigation in step (b)1. and any further parameters to be added to Section 2 of this Notice.
    Date: Complete
  3. Confirm the implementation of any short-term mitigation(s) required as specified in measure (b)2.
    Date: Complete
  4. Provide a report on the chosen design of treatment process and any additional control measures required, as specified in step (b)4.
    Date: Complete
  5. Confirm the upgrade of all regulatory sampling facilities on the island to be in line with the company standard, as specified in measure (b)5.
    Date: 31 January 2025
  6. Confirm completion of the installation and commissioning of the required treatment stages and control measures, as described in (b)6. Provide evidence of the updated site policies and procedures and any relevant additional training delivered to staff, as specified in (b)7.
    Date: 30 April 2025
  7. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: Complete
  8. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  9. Submit a report in the event that any completed measures of this Notice need to be altered in any way, for any reason.
    Date: Ongoing for the duration of this Notice
  10. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 April 2026

Further Details of this Notice:

  1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
  2. Under regulation 28(6) the Inspectorate, on behalf of the Secretary of State, may by notice served on the Company, revoke or vary this Notice.
  3. Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991 (as amended).

Signed

Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
13 August 2024
Reference: ISC-2021-00006 (v6)

Annex 1

Existing hazards and any other Hazards identified through completion of step (b)1 of this notice.

Plump WTW


Hazard


Hazard ID


C001 – Total coliforms


98193


C002 – E. coli


98161


C003 – Enterococci


98162


C004A – C. perfringens


98163


C111 – Cryptosporidium


98195


D002A – Chloride


98197


A012 – Nitrate


98151


A009 Sodium


98150


F004 – Gross alpha


98171


F005 – Gross beta


98172


F031 – Radon


98204


F007 – Indicative Dose


98202


A001 – Colour


98147


A017 – TOC


109669


A017A – DOC


98184


D011 – THM


98199


A021 – Aluminium


98152


B001A – Arsenic


98186


A006 – pH


98181


H067 – PFAS


122873


A002 – Turbidity


98178


A004 – Taste


98180

Tommy’s WTW


Hazard


Hazard ID


C001 – Total coliforms


99243


C002 – E. coli


99211


C003 – Enterococci


99212


C004A – C. perfringens


99213


C111 – Cryptosporidium


99245


D002A – Chloride


99247


A001 – Colour


99197


A012 – Nitrate


99201


A009 – Sodium


99200


F004 – Gross alpha


99221


F005 – Gross beta


99222


F031 – Radon


99254


F007 – Indicative Dose


99252


A017 – TOC


109676


A017A – DOC


99234


D011 – THM


99249


A021 – Aluminium


99231


B001A – Arsenic


99202


A006 – pH


99236


H067 – PFAS


122880


A002 – Turbidity

99228


A004 – Taste


99230

Catchment

Catchment: useful links

EPA Advice Note

Guidance from Ireland’s Environmental Protection Agency on good borehole design.

WHO field guide

The World Health Organisation have produced a field guide to help those involved in small scale (mainly rural) water supply systems develop water safety plans.

Climate change, increasing population and environmental pressures are impacting on the resilience, sustainability, quality and security of existing sources of raw water to be treated for drinking water purposes. To improve the reliability of drinking water supplies and to ensure future provision of sufficient safe drinking water, new and alternative raw water sources will need to be developed.

A number of alternative sources of drinking water are currently being considered as part of the water companies’ water resource planning. One of the options being considered is recycled water, also known as water reuse. This source of water would be blended with and augment existing raw water sources and could supplement the raw water supply to drinking water treatment works.

What is water recycling?

The water cycle is a description of how water is in continuous circulation from the atmosphere to the Earth. In terms of drinking water supply and the water cycle, water precipitates from the atmosphere to the Earth and water is then abstracted from various sources, such as rivers, reservoirs and aquifers to be treated and supplied for human consumption, food production (for instance drinking water, bathing, or cooking) and other uses. Once used this water is then sent for treatment via a wastewater treatment works before being discharged back to the environment where it evaporates to the atmosphere and the cycle starts again.

Water recycling can provide a continuous and sustainable source of water, which is less prone to cyclical shortages such as droughts as it reclaims the most dilute portion of treated wastewater which would normally be returned to the environment.

The water element of that process which is reclaimed is then subjected to further advanced treatment at a water recycling plant before it is either sent to an existing water treatment works (known as direct water recycling) or discharged to a river, reservoir or aquifer (referred to as an environmental buffer) where it blends with other sources of water before being abstracted and further treated at a drinking water treatment works (known as indirect water recycling). Currently there are no proposed direct water recycling schemes. However some water companies will be developing indirect water recycling to help ensure a sufficient and sustainable supply. Indirect recycling is shown in the diagram below:

Indirect Recycling Scheme Diagram


The most common advanced water treatment processes that would be utilised at a water recycling plant would adopt a multi barrier approach which typically includes membrane filtration. Membrane filtration technology comprises membranes with an extremely small pore size, through which water is forced at high pressure to leave behind contaminants commonly found in treated wastewater including viruses, bacteria and other chemical contaminants.

How is water recycling regulated and is it safe to drink?

Water recycling schemes provide a safe source of drinking water. As with all water treatment facilities, they need to be designed appropriately and managed effectively. Water companies planning to utilise water recycling to supplement their raw water are required to ensure that all regulatory requirements in the drinking water quality legislation are met at all times.

The Drinking Water Inspectorate, as the independent drinking water quality regulator for England and Wales, has powers and duties to ensure that water companies are meeting the obligations relating to drinking water quality and sufficiency under the Water Industry Act 1991 and that water companies meets their regulatory duties as set out in the Water Supply (Water Quality) Regulations 2016 (as amended) and The Water Supply (Water Quality) Regulations 2018 (Wales) in full. These regulations cover water intended for human consumption and other domestic purposes (for example washing and laundry).

Drinking water that is supplied by a water company must be ‘wholesome’ and this is defined in law by having standards for a wide range of substances, organisms and properties of water in regulations that must not be breached. There is an additional requirement to make sure that it does not contain anything else that might be a potential danger to human health. The standards are set to be protective of public health and the definition of wholesome includes factors that might affect the look, smell or taste of the water. There is good agreement amongst experts worldwide on the science behind the setting of health based standards for drinking water and this expert evidence is documented by the World Health Organisation in its Guidelines for Drinking Water Quality. The legal standards in England and Wales are based on those which were set in Europe in the Drinking Water Directive 1998 and subsequent revisions, together with national standards set to maintain the high quality of water already achieved. The standards are strict and include wide safety margins. They cover:

• micro-organisms

• chemicals such as nitrate and pesticides

• metals such as lead and copper

• the way water looks and how it tastes

The requirements for water companies to ensure that the water supplied is wholesome and safe to drink applies to all sources and systems that supply drinking water, and this includes recycled water. This is achieved by understanding the risks all the way from the source to your tap, and making sure that the process contains multiple steps to address all risks so that the water produced does not rely on any one measure or process. This typically involves measures taken in the water catchment, managing how and when water is taken from the environment for treatment, and the treatment processes themselves.

There is a fundamental regulatory requirement for water companies to adequately treat and disinfect the water before it is supplied to consumers. The risk assessment should also include sufficient safeguards and failsafes which can detect and divert or prevent water entering supply before any of the standards or operational limits are breached.

The Inspectorate has set out how the existing regulatory framework applies to water recycling schemes to water companies in more detail in an Information Letter. Companies will have to demonstrate that they have met these requirements before any schemes are put into use.

Further information on the drinking water standards can be found here.

Is recycled water used elsewhere?

The use of recycled water to provide drinking water is a recognised practice internationally and has been successfully and safely used for a number of years in Singapore, Namibia, Australia and several locations in the USA.

How will I know if I am receiving recycled water?

Water companies that are proposing water recycling schemes will be consulting on their proposals as part of the water resource management plan process. The Inspectorate has been clear that engagement with consumers is a key stage when considering developing new sources of water such as recycled water and that consumers should be notified in advance of any changes of their water supply arrangements.

Will my water supply taste different if I receive recycled water?

Any change of a water source has the potential to affect the taste and feel of the drinking water supply for consumers. Water companies routinely move water around drinking water networks and introduce different sources of water to meet changes in demand, therefore they understand the challenges and how to manage them.

Recycled water which goes through membrane filtration is highly treated. Even the usual mineral content is reduced so there is the potential for recycled water to taste and feel different to the water supply consumers are typically used to. It is usual though for consumers to become accustomed to the characteristics of the new supply within a short period of time. Water companies can help make changes less noticeable by remineralising the pure water and/or blending it with existing sources of treated water and/or gradually introducing different sources.

What are the long-term implications of drinking recycled water?

Appropriate treatment of water sources reduces the presence of harmful properties, organisms and substances to provide a safe source of drinking water. As noted in a previous section companies supplying water for domestic purposes must meet the requirements of the Water Industry Act 1991 and the Water Supply (Water Quality) Regulations 2016 (as amended) and The Water Supply (Water Quality) Regulations 2018 (Wales) in full.

SEW (South East Water Ltd)

Report Data Range: For the whole year 2021

Table 1: Quality of water leaving service treatment works – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

Nitrite (Total)

A013B

0.1 mg NO2/l

720

0

<0.003

<0.003

0

Totals

720

0

Table 2: Quality of water leaving service treatment works – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

11,960

0

0

0

0

Total Coliforms (Confirmed)

C001

0 number/100 ml

11,960

1

0

0

0

Totals

23,920

1

Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

11,950

N/A

0

12

Residual Disinfectant – Free

C009

No abnormal change

11,959

N/A

0.16

1,424

Residual Disinfectant – Total

C010

No abnormal change

11,956

N/A

0.21

1.58

Turbidity – Indicator

A002A

1 NTU

11,958

2

<0.1

0.16

Totals

47,823

2

Table 4: Quality of water leaving service reservoirs – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of reservoirs failing standard

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

11,515

1

0

0

1

Total Coliforms (Confirmed)

C001

0 number/100 ml

11,515

2

0

0

0

Totals:

23,030

3

Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

11,530

N/A

0

>300

Residual Disinfectant – Free

C009

No abnormal change

11,523

N/A

0.05

0.7076

Residual Disinfectant – Total

C010

No abnormal change

11,523

N/A

0.11

0.85

Totals:

34,576

0

Table 6: Quality of water leaving bulk supply points – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of supply point with failures

Boron

D005A

1 mg B/l

165

0

<0.04

0.25204

0

Bromate

F003

10 µg BrO3/l

165

0

<0.8

3.784

0

Cyanide (Total)

B003

50 µg CN/l

165

0

<2

5.556

0

Fluoride (Total)

A027

1.5 mg F/l

164

0

<0.05

0.2247

0

Mercury (Total)

B005

1 µg Hg/l

164

0

<0.04

0.05

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

165

0

0

0.0327

0

Pesticides 2 4-D

P020

0.1 µg/l

165

0

<0.007

<0.007

0

Pesticides 2,4,5-T

P076

0.1 µg/l

165

0

<0.007

<0.007

0

Pesticides Aldrin

P002

0.03 µg/l

166

0

<0.007

<0.007

0

Pesticides Atrazine

P004

0.1 µg/l

169

0

<0.002

0.0165

0

Pesticides Bentazone

P006

0.1 µg/l

165

0

<0.007

<0.007

0

Pesticides Bromoxynil

P008

0.1 µg/l

165

0

<0.007

<0.007

0

Pesticides Carbendazim (Total)

P150

0.1 µg/l

169

0

<0.001

<0.001

0

Pesticides Carbetamide

P010

0.1 µg/l

169

0

<0.002

0.0102

0

Pesticides Chlortoluron

P014

0.1 µg/l

169

0

<0.003

0.0156

0

Pesticides Dicamba

P025

0.1 µg/l

165

0

<0.02

<0.02

0

Pesticides Dichlobenil

P098

0.1 µg/l

165

0

<0.006

<0.006

0

Pesticides Dichlorprop

P026

0.1 µg/l

165

0

<0.003

<0.003

0

Pesticides Dieldrin

P028

0.03 µg/l

162

0

<0.007

<0.007

0

Pesticides Diuron

P032

0.1 µg/l

169

0

<0.004

0.0076

0

Pesticides Epoxyconazole

P217

0.1 µg/l

169

0

<0.003

<0.003

0

Pesticides Fluroxypyr

P040

0.1 µg/l

165

0

<0.008

<0.008

0

Pesticides Flutriafol

P039

0.1 µg/l

169

0

<0.003

<0.003

0

Pesticides Gamma-HCH (Lindane)

P041

0.1 µg/l

166

0

<0.005

<0.005

0

Pesticides Heptachlor

P043

0.03 µg/l

166

0

<0.008

<0.008

0

Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

P044

0.03 µg/l

166

0

<0.005

<0.005

0

Pesticides Isoproturon

P048

0.1 µg/l

169

0

<0.003

<0.003

0

Pesticides Linuron

P051

0.1 µg/l

164

0

<0.003

<0.003

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

165

0

<0.008

<0.008

0

Pesticides MCPB

P055

0.1 µg/l

165

0

<0.008

<0.008

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

165

0

<0.005

0.0077

0

Pesticides Metaldehyde

P226

0.1 µg/l 

24

0

<0.008

0.01

0

Pesticides Oxadixyl

P154

0.1 µg/l

169

0

<0.003

<0.003

0

Pesticides Pendimethalin

P118

0.1 µg/l

169

0

<0.007

<0.007

0

Pesticides Prometryne

P070

0.1 µg/l

169

0

<0.002

<0.002

0

Pesticides Propazine

P066

0.1 µg/l

169

0

<0.002

<0.002

0

Pesticides Propyzamide

P071

0.1 µg/l

166

0

<0.005

<0.005

0

Pesticides Simazine

P073

0.1 µg/l

169

0

<0.003

0.006

0

Pesticides Terbutryn

P077

0.1 µg/l

169

0

<0.002

<0.002

0

Pesticides Tri-allate

P079

0.1 µg/l

166

0

<0.005

<0.005

0

Pesticides Triclopyr

P131

0.1 µg/l

165

0

<0.015

<0.015

0

Pesticides Trietazine

P132

0.1 µg/l

165

0

<0.004

<0.004

0

Totals

6,849

0

Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Chloride

D002A

250 mg Cl/l

166

0

10.9446

73.4229

Sulphate

A007

250 mg SO4/l

165

0

<2

75.996

Total Organic Carbon

A017

No abnormal change

165

N/A

<0.3

2.668

Totals

496

0

Table 9: Quality of water at consumer’s tap (zones) – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of zones failing standard

1 2-Dichloroethane (Total)

F001

3 µg/l

639

0

<0.12

<0.12

0

Antimony

B008A

5 µg Sb/l

605

0

<0.2

0.4

0

Arsenic (Total)

B001A

10 µg As/l

601

0

<1

6.5

0

Benzene (Total)

F002

1 µg/l

633

0

<0.02

<0.02

0

Benzo[a]Pyrene (Total)

D007

0.01 µg/l

620

0

<0.003

<0.003

0

Boron

D005A

1 mg B/l

394

0

<0.04

0.16375

0

Bromate

F003

10 µg BrO3/l

432

0

<0.8

4.534

0

Cadmium (Total)

B002

5 µg Cd/l

626

0

<0.12

<0.12

0

Chromium (Total)

B004

50 µg Cr/l

626

0

<0.5

3

0

Copper (Total)

A024A

2 mg Cu/l

589

0

<0.008

0.7959

0

Cyanide (Total)

B003

50 µg CN/l

394

0

<2

7.43

0

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

5,944

0

0

0

0

Enterococci (Confirmed)

C003

0 number/100 ml

627

1

0

0

1

Fluoride (Total)

A027

1.5 mg F/l

394

0

<0.05

0.42135

0

Lead (10 – will apply 25.12.2013)

B007B

10 µg Pb/l

593

1

<0.9

6.084

1

Mercury (Total)

B005

1 µg Hg/l 

394

0

<0.04

0.05

0

Nickel (Total) 

B006A 

20 µg Ni/l

589

1

<0.6

14.34

1

Nitrate (Total)

A012

50 mg NO3/l

625

0

<1

45.674

0

Nitrite – Consumer’s Taps

A013A

0.5 mg NO2/l

627

0

<0.003

<0.003

0

Nitrite/Nitrate formula

A013C

1 mg/l

627

0

0

0.91344

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

395

0

0

0.0396

0

Pesticides 2 4-D

P020

0.1 µg/l

404

0

<0.007

0.01095

0

Pesticides 2,4,5-T

P020

0.1 µg/l

404

0

<0.007

<0.007

0

Pesticides Aldrin

P002

0.03 µg/l

385

0

<0.007

<0.007

0

Pesticides Atrazine

P004

0.1 µg/l

397

0

<0.002

0.02002

0

Pesticides Bentazone

P006

0.1 µg/l

404

0

<0.007

0.02095

0

Pesticides Bromoxynil

P008

0.1 µg/l

404

0

<0.007

<0.007

0

Pesticides Carbendazim (Total)

P150

0.1 µg/l

397

0

<0.001

<0.001

0

Pesticides Carbetamide 

P010

0.1 µg/l

397

0

<0.002

0.00602

0

Pesticides Chlortoluron

P014

0.1 µg/l

397

0

<0.003

<0.003

0

Pesticides Dicamba

P025

0.1 µg/l

404

0

<0.02

<0.02

0

Pesticides Dichlobenil

P098

0.1 µg/l

386

0

<0.006

<0.006

0

Pesticides Dichlorprop

P026

0.1 µg/l

404

0

<0.003

<0.003

0

Pesticides Dieldrin

P028

0.03 µg/l

380

0

<0.007

<0.007

0

Pesticides Diuron

P032

0.1 µg/l

397

0

<0.004

0.00704

0

Pesticides Epoxyconazole

P217

0.1 µg/l

397

0

<0.003

<0.003

0

Pesticides Fluroxypyr

P040

0.1 µg/l

404

0

<0.008

<0.008

0

Pesticides Flutriafol

P039

0.1 µg/l

397

0

<0.003

0.004

0

Pesticides Gamma-HCH (Lindane)

P041

0.1 µg/l

387

0

<0.005

<0.005

0

Pesticides Heptachlor

P043

0.03 µg/l

387

0

<0.008

<0.008

0

Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

P044

0.03 µg/l

389

0

<0.005

<0.005

0

Pesticides Isoproturon

P048

0.1 µg/l

397

0

<0.003

<0.003

0

Pesticides Linuron

P051

0.1 µg/l

386

0

<0.003

<0.003

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

404

0

<0.008

<0.008

0

Pesticides MCPB

P055

0.1 µg/l

403

0

<0.008

<0.008

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

404

0

<0.005

<0.005

0

Pesticides Metaldehyde

P226

0.1 µg/l

245

0

<0.008

<0.013

0

Pesticides Oxadixyl

P154

0.1 µg/l 

397

0

<0.003

<0.01

0

Pesticides Pendimethalin

P118

0.1 µg/l

397

0

<0.007

<0.007

0

Pesticides Prometryne

P070

0.1 µg/l

397

0

<0.002

<0.002

0

Pesticides Propazine

P066

0.1 µg/l

397

0

<0.002

<0.002

0

Pesticides Propyzamide

P071

0.1 µg/l

387

0

<0.005

0.01224

0

Pesticides Simazine

P073

0.1 µg/l

397

0

<0.003

0.012

0

Pesticides Terbutryn

P077

0.1 µg/l

397

0

<0.002

<0.002

0

Pesticides Tri-allate

P079

0.1 µg/l

387

0

<0.005

<0.005

0

Pesticides Triclopyr

P131

0.1 µg/l

404

0

<0.015

<0.015

0

Pesticides Trietazine

P132

0.1 µg/l

397

0

<0.004

0.004

0

Polycyclic Aromatic Hydrocarbons (Total by Calculation)

B011F

0.1 µg/l

578

0

0

0

0

Selenium (Total)

B009

10 µg Se/l

607

0

<0.8

2.692

0

Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

D009B

10 µg/l

629

0

0

2.381

0

Trihalomethanes (Total by Calculation)

D011

100 µg/l

629

0

0

74.034

0

Totals

33,534

3

Table 10: Quality of water at consumer’s tap (zones) – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 percentile (representing a minimum)

99 percentile (representing a maximum)

No. of zones failing standard

Aluminium (Total)

A021

200 µg Al/l

2,006

0

<6

55.365

0

Colour

A001

20 mg/l Pt/Co

2,290

0

<1

1

0

Iron (Total)

A022

200 µg Fe/l

2,006

7

<4

119.632

6

Manganese (Total)

A023

50 µg Mn/l

2,006

1

<1.7

7.872

1

Odour

A003

0 Dilution number at 25°C

2,285

11

0

0

11

Sodium (Total)

A009

200 mg Na/l

607

0

3.816

63.184

0

Taste (Taste Quant)

A004

0 Dilution number at 25°C

2,281

0

0

0

0

Tetrachloromethane (Total)

D008

3 µg/l

643

0

<0.11

<0.11

0

Turbidity

A002

4 NTU

2,286

0

<0.1

0.3552

0

Totals

16,410

19

Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Ammonium (Total)

A014

0.5 mg NH4/l

627

0

<0.02

<0.02

Chloride

D002A

250 mg Cl/l

399

0

11.35

67.31

Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

627

0

0

0

Coliform Bacteria (Indicator)

C001A

0 number/100 ml

5,944

8

0

0

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

2,314

N/A

0

95

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

2,280

0

216

760

Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

A006

6.5 – 9.5 pH Value

2,277

0

7.1

8.1

Residual Disinfectant – Free

C009

No abnormal change

5,931

N/A

<0.05

0.8468

Residual Disinfectant – Total

C010

No abnormal change

5,930

N/A

0.1

1.01

Sulphate

A007

250 mg SO4/l

406

0

9.207

79.981

Total Organic Carbon

A017

No abnormal change

401

N/A

<0.3

2.9

Totals

27,136

8

Water supply arrangements

Company Assets

Number of treatment works

92

Number of service reservoirs 

157

Number of water supply zones

89

Length of mains pipe (km)

16,800km

Population Served

Population Supplied

3,797,000

Number of local authorities

41

Water Supplied

Water Supplied (l/day)

950,608,000

Percentage from surface sources

40%

Percentage of ground sources

55%

Percentage from mixed sources

5%

Area of supply

Barnet, Brent, Buckinghamshire, Central, Bedfordshire, Ealing, Essex, Harrow, Hertfordshire, Hillingdon, Kent, Luton, Surrey, Windsor and Maidenhead

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

961

0.25

2020

897

0.24

2021

900

0.24

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

3,066

0.81

2020

3,319

0.88

2021

3,036

0.80

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

A total of 1 consumer of Affinity Water directly contacted the DWI in 2021.

The Drinking Water Inspectorate (DWI) was formed in 1990 to provide independent reassurance that water supplies in England and Wales are safe and drinking water quality is acceptable to consumers.

We are a team of 55 staff with specialist knowledge of drinking water quality and supply, regulation, data management, and public health.

Marcus Rink, Chief Inspector

Marcus Rink is the Chief Inspector of Drinking Water, appointed in August 2015. As Chief Inspector he provides independent scrutiny of the water industry ensuring the safety and quality of water and public confidence through a robust regulatory framework. His role encompasses a range of statutory and non-statutory functions, discharging the duties of the Secretary of State for England and the Welsh Government to ensure companies meet their regulatory requirements and local authorities take action in respect of water supplies.

Laura Moss, Deputy Chief Inspector

Laura Moss is currently the Deputy Chief Inspector of Drinking Water Quality for England and Wales. Prior to that she had been a Principal Inspector with the Drinking Water Inspectorate since 2007, regulating drinking water quality in the public water supply industry in England and Wales, and more recently providing technical advice to local authorities carrying out their regulatory duties for private water supplies.

Nicholas Adjei, Deputy Chief Inspector

Nicholas Adjei is currently Deputy Chief Inspector. Nick has more than twenty-five years’ experience in engineering and consultancy. In previous roles Nick has headed up planning, monitoring and evaluation at an international NGO focusing on sustainable community-based projects across the southern hemisphere. He has experience of delivering major flood risk management schemes at the Environment Agency, he has previously been Head of Climate Change and Water Quality at OFWAT, and most recently with that regulator has been focussing on environmental issues and asset resilience in the water industry.

Water supply arrangements

Company Assets

Number of treatment works

92

Number of service reservoirs 

157

Number of water supply zones

89

Length of mains pipe (km)

16,800km

Population Served

Population Supplied

3,797,000

Number of local authorities

41

Water Supplied

Water Supplied (l/day)

950,608,000

Percentage from surface sources

40%

Percentage of ground sources

55%

Percentage from mixed sources

5%

Area of supply

Cotswolds, Redbridge

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

961

0.25

2020

897

0.24

2021

900

0.24

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

3,066

0.81

2020

3,319

0.88

2021

3,036

0.80

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

No consumers of Albion Water Limited directly contacted DWI in 2021.

What should I do if I am instructed to boil my tap water?

Heating water is one of the best ways to kill or inactivate bacteria, viruses or parasites. Most bacteria and viruses are killed at temperatures well below 100 degrees Celsius. To be safe, bring water to the boil so any bacteria or viruses that were in your water are killed or deactivated, making the water safe to drink. Boiling water is also effective against parasites such as Cryptosporidium.

If you receive a notice to boil your water before drinking, it means that the water in your tap might contain bacteria, viruses or parasites which could be harmful to your health. You should boil it before you drink it, use it to brush your teeth, make ice cubes, prepare food, clean feeding equipment or give it to your pets. You should boil your water until it reaches a rolling ball. Remove the water from the heat and allow it to cool naturally. The water should be stored in a clean container, in the fridge and should be discarded if not used within 24 hours. Please be cautious that boiling water can cause scalds

The water is still safe to shower and bathe in, but make sure it does not get into your mouth. It is also safe to wash dishes, if you use hot water and dry the dishes thoroughly before use. You can continue to wash clothes and flush the toilet as normal.

Very occasionally, you may receive instructions to cease using your water altogether. This may be due to an unexpected contamination of your water source. In this case, drink bottled water or an alternative supply provided by your water company or water provider.

Why am I being instructed to boil water?

Tap water in the UK is safe to drink without boiling. Before water reaches your tap, it undergoes a series of processes, which effectively kill or inactivate bacteria and viruses. These processes and the water are being continuously monitored and tested by your water company.

On rare occasions, the systems can fail. Usually, this will be due to weather emergencies or engineering works. The water company will issue a notice to the consumers in the affected area, instructing them to boil their water before drinking.

If you receive water from a private water supply, this notice will come from your local authority.

Overview

The possibility that pharmaceuticals may get into drinking water has been the subject of research since the 1960s.

The main sources of trace pharmaceuticals in the water environment arise from a combination of raw sewage, disperse occurrence from veterinary use caused by manure spreading and wastewater effluents.

One pharmaceutical which has been a focus of concern is the oestrogen component of the birth control pill. Oestrogens belong to a group of substances known as endocrine disrupters which are known to have the potential to impact on the aquatic environment, such as species of fish. More information on endocrine disrupters sometimes known as EDCs can be found in our consumer leaflet.

Research

Researchers have developed highly sensitive analytical methods to detect various pharmaceutical components, including ethynyl oestradiol (an active ingredient of the most popular brands of birth control pill). The methods can detect sub-nanogram (below parts per trillion) concentrations in samples of water.

Studies[1] have assessed the risk of likely specific pharmaceuticals which may be introduced into source waters via wastewater discharges and has included both desk based and monitoring studies. These studies have concluded that the non or very low detectable levels of pharmaceuticals in drinking water do not pose an appreciable risk to human health.

How do water companies protect drinking water?

By law water companies must assess the risk from pharmaceuticals being present in source waters and where a risk is identified they must monitor the water and have suitable water treatment in place.

The research and monitoring by water companies means that the public can be confident that pharmaceutical residues are not present in drinking water at levels which would pose a risk to health.

  1. Toxicological evaluation for pharmaceuticals in drinking water (dwi.gov.uk)

Consumers

The Drinking Water Inspectorate provide information and advice to consumers on the quality of drinking water.

The following is a list of subjects that either provide information on this website or direct you to the organisation that should be able help. If you are unable to find what you are looking for please contact us on dwi.enquiries@defra.gov.uk.

Website for customers to see how their water companies are performing

Customers can now quickly and easily see how their water company is performing and compare it to other companies. The information can be found on www.discoverwater.co.uk and has a comprehensive range of data covering water quality, public health, customer service and environmental aspects of water and sewerage services. Discover Water is a collaborative project. Led and funded by water companies, it has been delivered by an independent third party and overseen by a sector-wide group, including the sector’s regulators and consumer watchdog. The information used on Discover Water is already separately published by water companies, Ofwat, Defra, Drinking Water Inspectorate, Environment Agency and CCW.

Top tips for saving water

Water UK’s Water’s Worth Saving campaign provides top-tips and advice on saving water to improve the efficiency of your home and garden, reduce your energy bills, help fight climate change and preserve one of our most precious resources.

SST (South Staffordshire Water Plc)

Report Data Range: For the whole year 2021

Table 1: Quality of water leaving service treatment works – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

Nitrite (Total)

A013B

0.1 mg NO2/l

168

0

<0.006

<0.006

0

Totals

168

0

Table 2: Quality of water leaving service treatment works – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

4,392

0

0

0

0

Total Coliforms (Confirmed)

C001

0 number/100 ml

4,392

0

0

0

0

Totals

8,784

0

Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

4,392

N/A

0

5

Residual Disinfectant – Free

C009

No abnormal change

4,393

N/A

0.18

1.03

Turbidity – Indicator

A002A

1 NTU

4,392

1

<0.1

0.1207

Totals

13,177

1

Table 4: Quality of water leaving service reservoirs – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of reservoirs failing standard

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

1,625

0

0

0

0

Total Coliforms (Confirmed)

C001

0 number/100 ml

1,625

1

0

0

0

Totals:

3,250

1

Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

1,625

N/A

0

81

Residual Disinfectant – Free

C009

No abnormal change

1,625

N/A

0.03

0.52

Totals:

3,250

0

Table 6: Quality of water leaving bulk supply points – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of supply point with failures

1 2-Dichloroethane (Total)

F001

3 µg/l

162

0

<0.12

<0.12

0

Benzene (Total)

F002

1 µg/l

164

0

<0.02

<0.02

0

Cyanide (Total)

B003

50 µg CN/l

161

0

<2

<5

0

Mercury (Total)

B005

1 µg Hg/l 

161

0

<0.04

0.05

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

161

0

0

0.089

0

Pesticides 2 4-D

P020

0.1 µg/l

36

0

<0.007

0.023

0

Pesticides 2 4-DB

P082

0.1 µg/l

36

0

<0.007

<0.007

0

Pesticides 2,3,6-Tba

P074

0.1 µg/l

36

0

<0.009

<0.01

0

Pesticides 2,4,5-T

P076

0.1 µg/l

36

0

<0.007

<0.007

0

Pesticides Aldrin

P002

0.03 µg/l

8

0

<0.007

<0.007

0

Pesticides Atrazine

P004

0.1 µg/l

93

0

<0.002

0.018

0

Pesticides Benazolin (Total)

P138

0.1 µg/l

24

0

<0.009

<0.009

0

Pesticides Bentazone

P006

0.1 µg/l

77

0

<0.007

<0.007

0

Pesticides Bromacil

P086

0.1 µg/l

48

0

<0.003

<0.003

0

Pesticides Bromoxynil

P008

0.1 µg/l

36

0

<0.007

<0.007

0

Pesticides Carbetamide 

P010

0.1 µg/l

24

0

<0.002

0.007

0

Pesticides Chloridazon

P162

0.1 µg/l

44

0

<0.003

<0.003

0

Pesticides Chlormequat

P163

0.1 µg/l

24

0

<0.003

0.077

0

Pesticides Chlorpropham

P016

0.1 µg/l

32

0

<0.01

<0.01

0

Pesticides Chlorthal (Chlorthal Dimethyl) DCPA

P175

0.1 µg/l

116

0

<0.022

0.05466

0

Pesticides Chlortoluron

P014

0.1 µg/l

43

0

<0.003

0.007

0

Pesticides Clopyralid

P018

0.1 µg/l

36

0

<0.007

0.016

0

Pesticides Diazinon

P024

0.1 µg/l

39

0

<0.007

<0.007

0

Pesticides Dicamba

P025

0.1 µg/l

36

0

<0.02

<0.02

0

Pesticides Dichlorprop

P026

0.1 µg/l

44

0

<0.003

<0.003

0

Pesticides Dimethoate

P029

0.1 µg/l

24

0

<0.003

<0.003

0

Pesticides Diuron

P032

0.1 µg/l

106

0

<0.004

<0.004

0

Pesticides Flufenacet

P230

0.1 µg/l

36

0

<0.002

0.013

0

Pesticides Fluroxypyr

P040

0.1 µg/l

36

0

<0.008

0.019

0

Pesticides Flutriafol

P039

0.1 µg/l

44

0

<0.003

0.003

0

Pesticides Glyphosate

P042

0.1 µg/l

24

0

<0.005

<0.005

0

Pesticides Isoproturon

P048

0.1 µg/l

20

0

<0.003

<0.003

0

Pesticides Linuron

P051

0.1 µg/l

31

0

<0.003

<0.003

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

36

0

<0.008

0.014

0

Pesticides MCPB

P055

0.1 µg/l

20

0

<0.009

<0.009

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

36

0

<0.005

0.009

0

Pesticides Metaldehyde

P226

0.1 µg/l 

94

0

<0.008

0.01

0

Pesticides Metazachlor

P203

0.1 µg/l 

60

0

<0.003

0.027

0

Pesticides Methabenzthiazuron

P167

0.1 µg/l

12

0

<0.001

<0.001

0

Pesticides Monuron

P113

0.1 µg/l

15

0

<0.002

<0.002

0

Pesticides Pendimethalin

P118

0.1 µg/l

62

0

<0.007

<0.007

0

Pesticides Pentachlorophenol

P060

0.1 µg/l

12

0

<0.017

<0.017

0

Pesticides Picloram (Total)

P122

0.1 µg/l

36

0

<0.008

<0.008

0

Pesticides Propachlor

P126

0.1 µg/l

52

0

<0.017

<0.017

0

Pesticides Propazine

P066

0.1 µg/l

28

0

<0.002

<0.002

0

Pesticides Propham

P067

0.1 µg/l

56

0

<0.012

<0.012

0

Pesticides Propiconazole

P068

0.1 µg/l

12

0

<0.008

<0.008

0

Pesticides Propyzamide

P071

0.1 µg/l

44

0

<0.005

0.018

0

Pesticides Prothioconazole

P242

0.1 µg/l

24

0

<0.006

<0.006

0

Pesticides Quinmerac

P224

0.1 µg/l

44

0

<0.002

0.008

0

Pesticides Simazine

P073

0.1 µg/l

85

0

<0.003

0.006

0

Pesticides Tebuconazole

P177

0.1 µg/l

24

0

<0.002

0.005

0

Pesticides Triclopyr

P131

0.1 µg/l

36

0

<0.015

<0.015

0

Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

D009B

10 µg/l

161

0

0

2.947

0

Totals

2,947

0

Table 7: Quality of water leaving bulk supply points – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of supply points with failures

Tetrachloromethane (Total)

D008

3 µg/l

161

0

<0.11

<0.11

0

Totals

161

0

Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

168

0

0

0

Gross Alpha

F004

0.1 Bq/l

161

19

<0.02

0.2038

Gross Beta

F005

1 Bq/l

161

0

<0.28

0.3038

Tritium

F006

100 Bq/l

13

0

<6

<9

Totals

503

19

Table 9: Quality of water at consumer’s tap (zones) – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of supply point with failures

Antimony

B008A

5 µg Sb/l

282

0

<0.2

2.017

0

Arsenic (Total)

B001A

10 µg As/l

282

0

<1

2.917

0

Benzo[a]Pyrene (Total)

D007

0.01 µg/l

283

0

<0.003

<0.003

0

Boron

D005A

1 mg B/l

282

0

<0.04

0.10834

0

Bromate

F003

10 µg BrO3/l

282

0

<0.8

2.738

0

Cadmium (Total)

B002

5 µg Cd/l

282

0

<0.12

0.2517

0

Chromium (Total)

B004

50 µg Cr/l

282

0

<0.5

1.068

0

Copper (Total)

A024A

2 mg Cu/l

282

0

<0.008

0.3551

0

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

3,739

2

0

0

0

Enterococci (Confirmed)

C003

0 number/100 ml

281

1

0

0

1

Fluoride (Fluoridated)

A027A

1.2 mg F/l

282

39

0.121

1.1017

21

Fluoride (Total)

A027

1.5 mg F/l

281

0

0.121

1.1018

0

Lead (10 – will apply 25.12.2013)

B007B

10 µg Pb/l

282

0

<0.9

7.155

0

Nickel (Total)

B006A

20 µg Ni/l

282

0

<0.6

5.689

0

Nitrate (Total)

A012

50 mg NO3/l

282

0

<1

41.2

0

Nitrite – Consumer’s Taps

A013A

0.5 mg NO2/l

282

0

<0.003

<0.0047

0

Nitrite/Nitrate formula

A013C

1 mg/l

282

0

0

0.82302

0

Polycyclic Aromatic Hydrocarbons (Total by Calculation)

B011F

0.1 µg/l

285

0

0

0

0

Selenium (Total)

B009

10 µg Se/l

282

0

<0.8

<0.8

0

Trihalomethanes (Total by Calculation)

D011

100 µg/l

226

0

0

80.222

0

Totals

9,043

40

Table 10: Quality of water at consumer’s tap (zones) – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 percentile (representing a minimum)

99 percentile (representing a maximum)

No. of zones failing standard

Aluminium (Total)

A021

200 µg Al/l

1,310

0

<6

43.434

0

Colour

A001

20 mg/l Pt/Co

1,310

0

<1

2

0

Iron (Total)

A022

200 µg Fe/l

1,310

1

<4

48.923

1

Manganese (Total)

A023

50 µg Mn/l

1,310

0

<1.7

8.978

0

Odour

A003

0 Dilution number at 25°C

1,312

2

0

0

2

Sodium (Total)

A009

200 mg Na/l

282

0

8.296

60.6

0

Taste (Taste Quant)

A004

0 Dilution number at 25°C

1,308

0

0

0

0

Turbidity

A002

4 NTU

1,310

0

<0.1

0.3278

0

Totals

9,452

3

Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Ammonium (Total)

A014

0.5 mg NH4/l

1,310

0

<0.02

0.023

Chloride

D002A

250 mg Cl/l

282

0

25

92

Coliform Bacteria (Indicator)

C001A

0 number/100 ml

3,739

2

0

0

Colony Counts After 3 Days At 22øc (Colony Counts)

1,312

No abnormal change

1,312

N/A

0

56

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

1,310

0

334

823

Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

A006

6.5 – 9.5 pH Value

1,310

0

6.8

7.8

Residual Disinfectant – Free

C009

No abnormal change

3,740

N/A

0.03

0.6459

Residual Disinfectant – Total

C010

No abnormal change

3,740

N/A

0.09

0.84

Sulphate

A007

250 mg SO4/l

282

0

22.347

157

Total Organic Carbon

A017

No abnormal change

282

N/A

<0.3

3.734

Totals

17,307

2

ICW (Icosa Water Ltd)

Report Data Range: For the whole year 2021

Table 9: Quality of water at consumer’s tap (zones) – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of zones failing standard

1 2-Dichloroethane (Total)

F001

3 µg/l

41

0

<0.16

<0.16

0

Antimony

B008A

5 µg Sb/l

41

0

<0.07

0.3

0

Arsenic (Total)

B001A

10 µg As/l

41

0

0.12

0.73

0

Benzene (Total)

F002

1 µg/l

41

0

<0.06

<0.09

0

Benzo[a]Pyrene (Total)

D007

0.01 µg/l

41

0

<0.00039

<0.0006

0

Boron

D005A

1 mg B/l

41

0

0.0138

0.141

0

Bromate

F003

10 µg BrO3/l

41

0

<0.15

1.6

0

Cadmium (Total)

B002

5 µg Cd/l

41

0

<0.01

<0.03

0

Chromium (Total)

B004

50 µg Cr/l

41

0

<0.04

1.36

0

Copper (Total)

A024A

2 mg Cu/l

41

0

<0.0004

0.739

0

Cyanide (Total)

B003

50 µg CN/l

41

0

<1.2

<5.5

0

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

124

0

0

0

0

Enterococci (Confirmed)

C003

0 number/100 ml

42

0

0

0

0

Fluoride (Total)

A027

1.5 mg F/l

41

0

0.06

0.18

0

Lead (10 – will apply 25.12.2013)

B007B

10 µg Pb/l

41

0

0.02 

0.95

0

Mercury (Total)

B005

1 µg Hg/l 

41

0

<0.06

<0.06

0

Nickel (Total) 

B006A 

20 µg Ni/l

41

0

<0.18

6.39

0

Nitrate (Total)

A012

50 mg NO3/l

42

0

<2.11

41

0

Nitrite – Consumer’s Taps

A013A

0.5 mg NO2/l

42

0

<0.002

0.002

0

Nitrite/Nitrate formula

A013C

1 mg/l

42

0

0

0.82

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

42

0

0

0.042

0

Pesticides 2 4-D

P020

0.1 µg/l

13

0

<0.012

<0.012

0

Pesticides 2,3,6-Tba

P074

0.1 µg/l

5

0

<0.009

<0.01

0

Pesticides Aldrin

P002

0.03 µg/l

8

0

<0.005

<0.008

0

Pesticides Atrazine

P004

0.1 µg/l

22

0

0

0.01

0

Pesticides Atrazine Desisopropyl

P212

0.1 µg/l

1

0

<0.007

<0.007

0

Pesticides Benazolin (Total)

P138

0.1 µg/l

1

0

<0.011

<0.011

0

Pesticides Bentazone

P006

0.1 µg/l

27

0

<0.002

<0.004

0

Pesticides Boscalid

P231

0.1 µg/l

4

0

<0.009

<0.011

0

Pesticides Carbetamide 

P010

0.1 µg/l

12

0

<0.008

<0.01

0

Pesticides Chlormequat

P163

0.1 µg/l

5

0

<0.003

<0.003

0

Pesticides Chlorpyrifos (Chlorpyriphos Ethyl)

P017

0.1 µg/l

4

0

<0.016

<0.016

0

Pesticides Chlortoluron

P014

0.1 µg/l

1

0

<0.07

<0.07

0

Pesticides Clopyralid

P018

0.1 µg/l

10

0

<0.011

0.016

0

Pesticides Cyanazine

P092

0.1 µg/l

4

0

<0.006

<0.007

0

Pesticides Cyproconazole

P207

0.1 µg/l

4

0

<0.007

<0.008

0

Pesticides Desethylatrazine

P182

0.1 µg/l

1

0

0.024

0.024

0

Pesticides Dicamba

P025

0.1 µg/l

8

0

<0.012

<0.014

0

Pesticides Dichlorprop

P026

0.1 µg/l

8

0

<0.011

<0.017

0

Pesticides Dieldrin

P028

0.03 µg/l

12

0

<0.005

<0.009

0

Pesticides Diflufenican

P157

0.1 µg/l

4

0

<0.07

<0.09

0

Pesticides Diuron

P032

0.1 µg/l

15

0

<0.009

<0.01

0

Pesticides Epoxyconazole

P217

0.1 µg/l

4

0

<0.005

<0.006

0

Pesticides Flufenacet

P230

0.1 µg/l

9

0

<0.008

<0.009

0

Pesticides Fluroxypyr

P040

0.1 µg/l

9

0

<0.009

<0.012

0

Pesticides Flutriafol

P039

0.1 µg/l

10

0

<0.005

<0.005

0

Pesticides Glyphosate

P042

0.1 µg/l

9

0

<0.005

<0.005

0

Pesticides Heptachlor

P043

0.03 µg/l

12

0

<0.004

<0.005

0

Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

P044

0.03 µg/l

8

0

0

0

0

Pesticides Isoproturon

P048

0.1 µg/l

1

0

<0.005

<0.005

0

Pesticides Linuron

P051

0.1 µg/l

4

0

<0.007

<0.012

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

14

0

<0.008

<0.012

0

Pesticides MCPB

P055

0.1 µg/l

6

0

<0.018

<0.018

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

18

0

<0.007

0.009

0

Pesticides Metaldehyde

P226

0.1 µg/l 

24

0

<0.007

0.009

0

Pesticides Metazachlor

P203

0.1 µg/l 

14

0

<0.006

0.009

0

Pesticides Monuron

P113

0.1 µg/l

4

0

<0.007

<0.007

0

Pesticides Pendimethalin

P118

0.1 µg/l

9

0

<0.009

<0.02

0

Pesticides Pentachlorophenol

P060

0.1 µg/l

4

0

<0.015

<0.02

0

Pesticides Propiconazole

P068

0.1 µg/l

14

0

<0.007

<0.007

0

Pesticides Propyzamide

P071

0.1 µg/l

15

0

<0.007

0.011

0

Pesticides Quinmerac

P244

0.1 µg/l

14

0

<0.006

0.007

0

Pesticides Simazine

P073

0.1 µg/l

16

0

<0.004

0.008

0

Pesticides Spiroxamine

P239

0.1 µg/l

5

0

<0.006

<0.006

0

Pesticides Tebuconazole

P177

0.1 µg/l

10

0

<0.005

<0.009

0

Pesticides Tri-allate

P079

0.1 µg/l

4

0

<0.005

<0.006

0

Pesticides Triclopyr

P131

0.1 µg/l

17

0

<0.015

<0.028

0

Pesticides Trietazine

P132

0.1 µg/l

13

0

<0.004

<0.006

0

Polycyclic Aromatic Hydrocarbons (Total by Calculation)

B011F

0.1 µg/l

41

0

0

0.01

0

Selenium (Total)

B009

10 µg Se/l

41

0

<0.08

1.54

0

Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

D009B

10 µg/l

41

0

0

0

0

Trihalomethanes (Total by Calculation)

D011

100 µg/l

41

0

1.73

83.24

0

Totals

1549

0

Table 10: Quality of water at consumer’s tap (zones) – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 percentile (representing a minimum)

99 percentile (representing a maximum)

No. of zones failing standard

Aluminium (Total)

A021

200 µg Al/l

42

0

<6.9

19.7

0

Colour

A001

20 mg/l Pt/Co

45

0

<2.8

<2.9

0

Iron (Total)

A022

200 µg Fe/l

42

0

<0.07

29.5

0

Manganese (Total)

A023

50 µg Mn/l

42

0

<0.085

3.11

0

Odour

A003

0 Dilution number at 25°C

45

0

0

0

0

Sodium (Total)

A009

200 mg Na/l

41

0

9.72

68

0

Taste (Taste Quant)

A004

0 Dilution number at 25°C

45

0

0

0

0

Tetrachloromethane (Total)

D008

3 µg/l

41

0

<0.13

<0.16

0

Turbidity

A002

4 NTU

46

0

<0.13

0.25

0

Totals

389

0

Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Ammonium (Total)

A014

0.5 mg NH4/l

42

0

<0.008

0.094

Chloride

D002A

250 mg Cl/l

41

0

20.7

95.7

Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

42

0

0

0

Coliform Bacteria (Indicator)

C001A

0 number/100 ml

124

1

0

6

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

46

N/A

0

351

Colony Counts After 48 Hours At 37øc (Colony Counts)

C013

No abnormal change

46

N/A

0

494

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

46

0

366

921

Gross Alpha

F004

0.1 Bq/l

27

0

<0.018

<0.045

Gross Beta

F005

1 Bq/l

27

0

<0.018

0.6

Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

A006

6.5 – 9.5 pH Value

45

0

7.07

8.01

Residual Disinfectant – Total

C010

No abnormal change

123

N/A

0.0572

0.864

Sulphate

A007

250 mg SO4/l

41

0

7.43

116

Total Organic Carbon

A017

No abnormal change

41

N/A

0.3

2.6

Tritium

F006

100 Bq/l

27

0

<5.6

<10

Totals

718

1

SRN (Southern Water Services Ltd)

Report Data Range: For the whole year 2021

Table 1: Quality of water leaving service treatment works – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

Nitrite (Total)

A013B

0.1 mg NO2/l

633

0

<0.002

0.00498

0

Totals

633

0

Table 2: Quality of water leaving service treatment works – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

12,600

4

0

0

4

Total Coliforms (Confirmed)

C001

0 number/100 ml

12,600

6

0

0

6

Totals

25,200

10

Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

12,621

N/A

0

4

Residual Disinfectant – Free

C009

No abnormal change

12,650

N/A

0.24

1.05

Residual Disinfectant – Total

C010

No abnormal change

12,650

N/A

0.32

1.15

Turbidity – Indicator

A002A

1 NTU

12,609

1

<0.15

0.393

Totals

50,530

1

Table 4: Quality of water leaving service reservoirs – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of reservoirs failing standard

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

10,533

2

0

0

2

Total Coliforms (Confirmed)

C001

0 number/100 ml

10,533

12

0

0

0

Totals:

21,066

14

Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

10,565

N/A

0

14

Residual Disinfectant – Free

C009

No abnormal change

10,568

N/A

0.11

0.81

Residual Disinfectant – Total

C010

No abnormal change

10,568

N/A

0.1869

0.87

Totals:

31,701

0

Table 6: Quality of water leaving bulk supply points – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of supply point with failures

1 2-Dichloroethane (Total)

F001

3 µg/l

633

0

<0.16

<0.16

0

Benzene (Total)

F002

1 µg/l

633

0

<0.06

<0.09

0

Boron

D005A

1 mg B/l

633

0

0.018946

0.078414

0

Bromate

F003

10 µg BrO3/l

633

0

<0.15

1.8

0

Cyanide (Total)

B003

50 µg CN/l

633

0

<1.2

<5.5

0

Fluoride (Total)

A027

1.5 mg F/l

633

0

0.06

0.2266

0

Mercury (Total)

B005

1 µg Hg/l

633

0

<0.04

<0.06

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

636

0

0

0.088

0

Pesticides 2 4-D

P020

0.1 µg/l

264

0

<0.012

<0.012

0

Pesticides Aldrin

P002

0.03 µg/l

636

0

<0.005

<0.008

0

Pesticides Atrazine

P004

0.1 µg/l

531

0

<0.004

0.022

0

Pesticides Atrazine Desisopropyl

P212

0.1 µg/l

114

0

<0.007

0.05295

0

Pesticides Benazolin (Total)

P138

0.1 µg/l

64

0

<0.01

0.011

0

Pesticides Bentazone

P006

0.1 µg/l

520

0

<0.002

0.06658

0

Pesticides Boscalid

P231

0.1 µg/l

101

0

<0.009

<0.011

0

Pesticides Bromacil

P086

0.1 µg/l

264

0

<0.007

0.02145

0

Pesticides Carbendazim (Total)

P150

0.1 µg/l

509

0

<0.003

<0.003

0

Pesticides Carbetamide

P010

0.1 µg/l

121

0

<0.008

<0.01468

0

Pesticides Chlormequat

P163

0.1 µg/l

209

0

<0.003

<0.0138

0

Pesticides Chlorothalonil

P015

0.1 µg/l

108

0

<0.006

<0.014

0

Pesticides Chlorpyrifos (Chlorpyriphos Ethyl)

P017

0.1 µg/l

48

0

<0.016

<0.016

0

Pesticides Chlortoluron

P014

0.1 µg/l

290

0

<0.006

<0.00952

0

Pesticides Clopyralid

P018

0.1 µg/l

169

0

<0.011

0.0414

0

Pesticides Cyanazine

P092

0.1 µg/l

392

0

<0.006

<0.014

0

Pesticides Cypermethrin

P094

0.1 µg/l

84

0

<0.005

<0.008

0

Pesticides Cyproconazole

P207

0.1 µg/l

133

0

<0.007

<0.008

0

Pesticides Desethylatrazine

P182

0.1 µg/l

113

0

<0.005

0.03186

0

Pesticides Diazinon

P024

0.1 µg/l

176

0

<0.006

<0.01091

0

Pesticides Dicamba

P025

0.1 µg/l

209

0

<0.012

<0.014

0

Pesticides Dichlorprop

P026

0.1 µg/l

108

0

<0.011

<0.017

0

Pesticides Dieldrin

P028

0.03 µg/l

636

0

<0.005

<0.009

0

Pesticides Diflufenican

P157

0.1 µg/l

100

0

<0.007

<0.009

0

Pesticides Diuron

P032

0.1 µg/l

241

0

<0.009

<0.01

0

Pesticides Epoxyconazole

P217

0.1 µg/l

356

0

<0.005

<0.006

0

Pesticides Fenpropimorph

P037

0.1 µg/l

377

0

<0.004

<0.004

0

Pesticides Flufenacet

P230

0.1 µg/l

149

0

<0.008

0.0245

0

Pesticides Fluroxypyr

P040

0.1 µg/l

164

0

<0.009

<0.01235

0

Pesticides Flusilazole

P159

0.1 µg/l

33

0

<0.006

<0.007

0

Pesticides Flutriafol

P039

0.1 µg/l

377

0

<0.005

0.01322

0

Pesticides Fluxapyroxad

P274

0.1 µg/l

117

0

<0.009

<0.011

0

Pesticides Gamma-HCH (Lindane)

P041

0.1 µg/l

16

0

<0.005

<0.006

0

Pesticides Glyphosate

P042

0.1 µg/l

360

0

<0.005

<0.025

0

Pesticides Heptachlor

P043

0.03 µg/l

636

0

<0.004

<0.005

0

Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

P044

0.03 µg/l

636

0

<0.005

<0.007

0

Pesticides Isoproturon

P048

0.1 µg/l

273

0

<0.005

<0.01668

0

Pesticides Lambda-Cyhalothrin

P216

0.1 µg/l

44

0

<0.006

<0.006

0

Pesticides Linuron

P051

0.1 µg/l

85

0

<0.007

<0.012

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

196

0

<0.008

<0.01212

0

Pesticides MCPB

P055

0.1 µg/l

88

0

<0.018

<0.018

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

300

0

<0.007

<0.009

0

Pesticides Mepiquat Chloride

P280

0.1 µg/l

101

0

<0.004

<0.02

0

Pesticides Metaldehyde

P226

0.1 µg/l 

559

0

<0.007

<0.035

0

Pesticides Metazachlor

P203

0.1 µg/l

295

0

<0.006

0.02316

0

Pesticides Methabenzthiazuron

P167

0.1 µg/l

219

0

<0.005

<0.006

0

Pesticides Pendimethalin

P118

0.1 µg/l

337

0

<0.009

<0.02

0

Pesticides Pendimethalin

P118

0.1 µg/l

337

0

<0.009

<0.02

0

Pesticides Pentachlorobenzene

P241

0.1 µg/l

84

0

<0.005

<0.006

0

Pesticides Pentachlorophenol

P060

0.1 µg/l

56

0

<0.015

<0.02

0

Pesticides Picloram (Total)

P122

0.1 µg/l

264

0

<0.013

<0.019

0

Pesticides Pirimicarb

P064

0.1 µg/l

280

0

<0.005

<0.007

0

Pesticides Prometryne

P070

0.1 µg/l

272

0

<0.004

<0.005

0

Pesticides Propazine

P066

0.1 µg/l

449

0

<0.004

<0.007

0

Pesticides Propiconazole

P068

0.1 µg/l

181

0

<0.007

<0.007

0

Pesticides Propyzamide

P071

0.1 µg/l

144

0

<0.007

0.0162

0

Pesticides Prosulfocarb

P243

0.1 µg/l

197

0

<0.007

<0.009

0

Pesticides Quinmerac

P244

0.1 µg/l

417

0

<0.006

<0.007

0

Pesticides Simazine

P073

0.1 µg/l

568

0

<0.004

0.01131

0

Pesticides Spiroxamine

P239

0.1 µg/l

440

0

<0.006

<0.006

0

Pesticides Tebuconazole

P177

0.1 µg/l

141

0

<0.005

<0.009

0

Pesticides Terbuthylazine

P173

0.1 µg/l

37

0

<0.003

<0.005

0

Pesticides Terbutryn

P077

0.1 µg/l

282

0

<0.003

<0.005

0

Pesticides Tri-allate

P079

0.1 µg/l

173

0

<0.005

<0.006

0

Pesticides Triclopyr

P131

0.1 µg/l

108

0

<0.015

<0.028

0

Pesticides Trietazine

P132

0.1 µg/l

354

0

<0.004

0.01

0

Pesticides Trifluralin

P081

0.1 µg/l

16

0

<0.004

<0.008

0

Radon

F031

100 Bq/l

196

0

<0.4865

11.224

0

Totals

21,584

0

Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Chloride

D002A

250 mg Cl/l

633

0

10.1

67.162

Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

633

1

0

0

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

2,868

0

257

773.62

Gross Alpha

F004

0.1 Bq/l

201

0

<0.01802

0.06278

Gross Beta

F005

1 Bq/l

198

0

0.01899

0.25253

Sulphate

A007

250 mg SO4/l

633

0

3.9568

74.2

Total Organic Carbon

A017

No abnormal change

634

N/A

0.5

2.9

Tritium

F006

100 Bq/l

198

0

<5.6

<8.5

Totals

5,998

1

Table 9: Quality of water at consumer’s tap (zones) – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of zones failing standard

1 2-Dichloroethane (Total)

F001

3 µg/l

9

0

<0.16

<0.16

0

Antimony

B008A

5 µg Sb/l

541

0

0.03

0.3216

0

Arsenic (Total)

B001A

10 µg As/l

541

0

0.14

0.73

0

Benzene (Total)

F002

1 µg/l

9

0

<0.06

<0.06

0

Benzo[a]Pyrene (Total)

D007

0.01 µg/l

548

0

<0.00057

<0.00057

0

Boron

D005A

1 mg B/l

9

0

<0.0319

0.119

0

Bromate

F003

10 µg BrO3/l

136

0

<0.15

1.326

0

Cadmium (Total)

B002

5 µg Cd/l

541

0

<0.01

<0.03

0

Chromium (Total)

B004

50 µg Cr/l

541

0

0.0584

0.8816

0

Copper (Total)

A024A

2 mg Cu/l

541

0

0.0014

0.93804

0

Cyanide (Total)

B003

50 µg CN/l

9

0

<1.4

<5.5

0

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

6,695

1

0

0

1

Enterococci (Confirmed)

C003

0 number/100 ml

541

0

0

0

0

Fluoride (Total)

A027

1.5 mg F/l

9

0

0.09

0.13

0

Lead (10 – will apply 25.12.2013)

B007B

10 µg Pb/l

541

5

<0.04

9.959

4

Mercury (Total)

B005

1 µg Hg/l 

9

0

<0.06

<0.06

0

Nickel (Total) 

B006A 

20 µg Ni/l

541

2

0.4342

12.15

1

Nitrate (Total)

A012

50 mg NO3/l

542

0

<2.11

44.157

0

Nitrite – Consumer’s Taps

A013A

0.5 mg NO2/l

542

0

<0.002

0.01528

0

Nitrite/Nitrate formula

A013C

1 mg/l

542

0

0

0.88

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

9

0

0

0.077

0

Pesticides 2 4-D

P020

0.1 µg/l

9

0

<0.012

0.014

0

Pesticides Aldrin

P002

0.03 µg/l

9

0

<0.005

<0.008

0

Pesticides Atrazine

P004

0.1 µg/l

9

0

<0.004

<0.005

0

Pesticides Benazolin (Total)

P138

0.1 µg/l

9

0

<0.01

<0.011

0

Pesticides Bentazone

P006

0.1 µg/l

9

0

<0.002

<0.004

0

Pesticides Boscalid

P231

0.1 µg/l

9

0

<0.009

<0.011

0

Pesticides Bromacil

P086

0.1 µg/l

9

0

<0.007

<0.009

0

Pesticides Bromoxynil

P008

0.1 µg/l

9

0

<0.009

<0.009

0

Pesticides Carbendazim (Total)

P150

0.1 µg/l

9

0

<0.003

<0.003

0

Pesticides Carbetamide 

P010

0.1 µg/l

9

0

<0.008

<0.01

0

Pesticides Chlormequat

P163

0.1 µg/l

9

0

<0.003

<0.003

0

Pesticides Chlorothalonil

P015

0.1 µg/l

9

0

<0.006

<0.014

0

Pesticides Chlorpyrifos (Chlorpyriphos Ethyl)

P017

0.1 µg/l

9

0

<0.016

<0.016

0

Pesticides Chlortoluron

P014

0.1 µg/l

9

0

<0.006

<0.007

0

Pesticides Clopyralid

P018

0.1 µg/l

9

0

<0.011

0.035

0

Pesticides Cyanazine

P092

0.1 µg/l

9

0

<0.006

<0.007

0

Pesticides Cyproconazole

P207

0.1 µg/l

9

0

<0.007

<0.008

0

Pesticides Diazinon

P024

0.1 µg/l

9

0

<0.006

<0.007

0

Pesticides Dicamba

P025

0.1 µg/l

9

0

<0.012

<0.028

0

Pesticides Dichlorprop

P026

0.1 µg/l

9

0

<0.011

<0.017

0

Pesticides Dieldrin

P028

0.03 µg/l

9

0

<0.005

<0.009

0

Pesticides Diflufenican

P157

0.1 µg/l

9

0

<0.007

<0.009

0

Pesticides Diuron

P032

0.1 µg/l

9

0

<0.009

<0.01

0

Pesticides Epoxyconazole

P217

0.1 µg/l

9

0

<0.005

<0.006

0

Pesticides Fenpropimorph

P037

0.1 µg/l

9

0

<0.004

<0.005

0

Pesticides Flufenacet

P230

0.1 µg/l

9

0

<0.008

0.013

0

Pesticides Fluroxypyr

P040

0.1 µg/l

9

0

<0.009

<0.012

0

Pesticides Flusilazole

P159

0.1 µg/l

9

0

<0.006

<0.007

0

Pesticides Flutriafol

P039

0.1 µg/l

9

0

<0.005

<0.005

0

Pesticides Gamma-HCH (Lindane)

P041

0.1 µg/l

9

0

<0.005

<0.006

0

Pesticides Glyphosate

P042

0.1 µg/l

9

0

<0.005

<0.005

0

Pesticides Heptachlor

P043

0.03 µg/l

9

0

<0.004

<0.005

0

Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

P044

0.03 µg/l

9

0

<0.005

<0.007

0

Pesticides Isoproturon

P048

0.1 µg/l

9

0

<0.005

<0.006

0

Pesticides Linuron

P051

0.1 µg/l

9

0

<0.007

<0.012

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

9

0

<0.008

<0.012

0

Pesticides MCPB

P055

0.1 µg/l

9

0

<0.018

<0.018

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

9

0

<0.007

<0.009

0

Pesticides Mepiquat Chloride

P280

0.1 µg/l

9

0

<0.004

<0.004

0

Pesticides Metaldehyde

P226

0.1 µg/l

9

0

<0.007

0.019

0

Pesticides Metazachlor

P203

0.1 µg/l 

9

0

<0.006

<0.007

0

Pesticides Methabenzthiazuron

P167

0.1 µg/l

9

0

<0.005

<0.006

0

Pesticides Parathion (Parathion ethyl)

P059

0.1 µg/l

9

0

<0.007

<0.012

0

Pesticides Pendimethalin

P118

0.1 µg/l

9

0

<0.009

<0.02

0

Pesticides Pentachlorophenol

P060

0.1 µg/l

9

0

<0.015

<0.02

0

Pesticides Picloram (Total)

P122

0.1 µg/l

9

0

<0.013

<0.026

0

Pesticides Pirimicarb

P064

0.1 µg/l

9

0

<0.005

<0.007

0

Pesticides Prometryne

P070

0.1 µg/l

9

0

<0.004

<0.005

0

Pesticides Propazine

P066

0.1 µg/l

9

0

<0.004

<0.007

0

Pesticides Propiconazole

P068

0.1 µg/l

9

0

<0.007

<0.007

0

Pesticides Propyzamide

P071

0.1 µg/l

9

0

<0.007

0.01

0

Pesticides Prosulfocarb

P243

0.1 µg/l

9

0

<0.007

<0.009

0

Pesticides Quinmerac

P244

0.1 µg/l

9

0

<0.006

0.011

0

Pesticides Simazine

P073

0.1 µg/l

9

0

<0.004

<0.005

0

Pesticides Spiroxamine

P239

0.1 µg/l

9

0

<0.006

<0.006

0

Pesticides Tebuconazole

P177

0.1 µg/l

9

0

<0.005

<0.009

Pesticides Terbutryn

P077

0.1 µg/l

9

0

<0.003

<0.005

0

Pesticides Tri-allate

P079

0.1 µg/l

9

0

<0.005

<0.006

0

Pesticides Triclopyr

P131

0.1 µg/l

9

0

<0.015

<0.028

0

Pesticides Trietazine

P132

0.1 µg/l

9

0

<0.004

<0.006

0

Pesticides Trifluralin

P081

0.1 µg/l

9

0

<0.004

<0.007

0

Polycyclic Aromatic Hydrocarbons (Total by Calculation)

B011F

0.1 µg/l

541

0

0

0.00258

0

Radon

F031

100 Bq/l

9

0

<0.5

3.3

0

Selenium (Total)

B009

10 µg Se/l

541

0

0.27

1.2016

0

Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

D009B

10 µg/l

541

0

0

1.6964

0

Trihalomethanes (Total by Calculation)

D011

100 µg/l

541

0

1.3482

67.7684

0

Totals

16,118

8

Table 10: Quality of water at consumer’s tap (zones) – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 percentile (representing a minimum)

99 percentile (representing a maximum)

No. of zones failing standard

Aluminium (Total)

A021

200 µg Al/l

2,404

0

<6.9

26.59

0

Colour

A001

20 mg/l Pt/Co

2,421

0

<2.8

<2.8

0

Iron (Total)

A022

200 µg Fe/l

2,404

7

<3.72

70.935

6

Manganese (Total)

A023

50 µg Mn/l

2,405

1

<0.3

3.8164

1

Odour

A003

0 Dilution number at 25°C

2,425

6

0

0

6

Sodium (Total)

A009

200 mg Na/l

541

0

5.3968

40.316

0

Taste (Taste Quant)

A004

0 Dilution number at 25°C

2,422

6

0

0

5

Tetrachloromethane (Total)

D008

3 µg/l

541

0

<0.13

<0.16

0

Turbidity

A002

4 NTU

2,421

0

<0.15

0.39834

0

Totals

17,984

20

Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Ammonium (Total)

A014

0.5 mg NH4/l

524

0

<0.008

<0.01614

Chloride

D002A

250 mg Cl/l

9

0

10.3

39.7

Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

9

0

0

0

Coliform Bacteria (Indicator)

C001A

0 number/100 ml

6,695

14

0

0

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

2,422

N/A

0

37

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

12

0

348

613

Gross Alpha

F004

0.1 Bq/l

9

0

<0.016

<0.034

Gross Beta

F005

1 Bq/l

9

0

0.02

0.137

Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

A006

6.5 – 9.5 pH Value

2,422

0

7.11

7.8277

Residual Disinfectant – Free

C009

No abnormal change

6,705

N/A

0.05

0.76

Residual Disinfectant – Total

C010

No abnormal change

6,705

N/A

0.12

0.81

Sulphate

A007

250 mg SO4/l

9

0

4.86

64.9

Total Organic Carbon

A017

No abnormal change

9

N/A

<0.7

4.7

Tritium

F006

100 Bq/l

9

0

<5.6

<8.5

Totals

25,556

14

Water supply arrangements

Company Assets

Number of treatment works

17

Number of service reservoirs 

165

Number of water supply zones

27

Length of mains pipe (km)

6,904km

Population Served

Population Supplied

1,232,000

Number of local authorities

9

Water Supplied

Water Supplied (l/day)

277,210,000

Percentage from surface sources

81%

Percentage of ground sources

13%

Percentage from mixed sources

6%

Area of supply

Gloucestershire, Wiltshire, Bristol, Somerset

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

734

0.61

2020

565

0.46

2021

595

0.48

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

1,766

1.46

2020

1,789

1.46

2021

1,770

1.44

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

No consumers of Bristol Water plc directly contacted DWI in 2021.

Reg 31 (Demo)

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AFW (Affinity Water Ltd)

Report Data Range: For the whole year 2021

Table 1: Quality of water leaving service treatment works – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

Nitrite (Total)

A013B

0.1 mg NO2/l

1,112

0

< 0.007

0.01509

0

Totals

1,112

0

Table 2: Quality of water leaving service treatment works – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

13,398

0

0

0

0

Total Coliforms (Confirmed)

C001

0 number/100 ml

13,398

1

0

0

1

Totals

26,796

1

Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

13,398

N/A

0

4

Residual Disinfectant – Total

C010

No abnormal change

13,404

N/A

0

4

Turbidity – Indicator

A002A

1 NTU

13,400

0

<0.1

0.33

Totals

40,202

0

Table 4: Quality of water leaving service reservoirs – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of reservoirs failing standard

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

7,643

0

0

0

0

Total Coliforms (Confirmed)

C001

0 number/100 ml

7,643

5

0

0

0

Totals:

15,286

5

Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

7,642

N/A

0

260

Residual Disinfectant – Total

C010

No abnormal change

7,645

N/A

0.06

0.78

Totals:

15,287

0

Table 9: Quality of water at consumer’s tap (zones) – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of zones failing standard

1 2-Dichloroethane (Total)

F001

3 µg/l

689

0

<0.09

<0.14

0

Antimony

B008A

5 µg Sb/l

677

0

<0.2

0.51522

0

Arsenic (Total)

B001A

10 µg As/l

677

0

<1

2.5698

0

Benzene (Total)

F002

1 µg/l

691

0

<0.03

<0.07

0

Benzo[a]Pyrene (Total)

D007

0.01 µg/l

700

0

<0.0018

<0.0018

0

Boron

D005A

1 mg B/l

677

0

<0.1

0.3476

0

Bromate

F003

10 µg BrO3/l

677

0

<0.3

3.522

0

Cadmium (Total)

B002

5 µg Cd/l

677

0

<0.2

<0.2

0

Chromium (Total)

B004

50 µg Cr/l

677

0

<0.5

5.031

0

Copper (Total)

A024A

2 mg Cu/l

677

0

<0.019

0.80548

0

Cyanide (Total)

B003

50 µg CN/l

678

0

<2.7

3.621

0

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

9,664

0

0

0

0

Enterococci (Confirmed)

C003

0 number/100 ml

675

0

0

0

0

Fluoride (Total)

A027

1.5 mg F/l

677

0

0.05578

0.65522

0

Lead (10 – will apply 25.12.2013)

B007B

10 µg Pb/l

677

2

<1 

6.0838

2

Mercury (Total)

B005

1 µg Hg/l 

677

0

<0.1 

<0.1

0

Nickel (Total) 

B006A 

20 µg Ni/l

677

2

<2

7.4802

2

Nitrate (Total)

A012

50 mg NO3/l

1,000

0

<3.4

43.375

0

Nitrite – Consumer’s Taps

A013A

0.5 mg NO2/l

1,000

0

<0.007

0.09596

0

Nitrite/Nitrate formula

A013C

1 mg/l

988

0

0

<0.83288

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

676

0

0

0.08669

0

Pesticides 2 4-D

P020

0.1 µg/l

295

0

<0.014

<0.016

0

Pesticides Atrazine

P004

0.1 µg/l

683

0

<0.013

0.029

0

Pesticides Carbetamide 

P010

0.1 µg/l

306

0

<0.013

<0.017

0

Pesticides Clopyralid

P018

0.1 µg/l

296

0

<0.024

0.04203

0

Pesticides Desethylatrazine

P182

0.1 µg/l

686

0

<0.008

0.05939

0

Pesticides Glyphosate

P042

0.1 µg/l

293

0

<0.005

<0.025

0

Pesticides Isoproturon

P048

0.1 µg/l

17

0

<0.012

<0.016

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

306

0

<0.011

0.019

0

Pesticides Metaldehyde

P226

0.1 µg/l 

306

0

<0.02

0.05472

0

Pesticides Metazachlor

P203

0.1 µg/l 

299

0

<0.011 

<0.015

0

Pesticides Propyzamide

P071

0.1 µg/l

299

0

<0.019

0.043

0

Pesticides Simazine

P073

0.1 µg/l

299

0

<0.017

<0.022

0

Polycyclic Aromatic Hydrocarbons (Total by Calculation)

B011F

0.1 µg/l

690

0

0

0

0

Selenium (Total)

B009

10 µg Se/l

677

0

<1

3.0066

0

(Total by Calculation)

D009B

10 µg/l

680

0

0

2.2857

0

Trihalomethanes (Total by Calculation)

D011

100 µg/l

681

0

0.467

53.5266

0

Totals

31,028

4

Table 10: Quality of water at consumer’s tap (zones) – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 percentile (representing a minimum)

99 percentile (representing a maximum)

No. of zones failing standard

Aluminium (Total)

A021

200 µg Al/l

2,341

1

<5

71.058

1

Colour

A001

20 mg/l Pt/Co

3,369

0

<2.5

3.6

0

Iron (Total)

A022

200 µg Fe/l

2,336

1

<15

35.026

1

Manganese (Total)

A023

50 µg Mn/l

2,336

0

<1

2.5619

0

Odour

A003

0 Dilution number at 25°C

3,368

0

0

0

0

Sodium (Total)

A009

200 mg Na/l

677

0

8.0834

51.288

0

Taste (Taste Quant)

A004

0 Dilution number at 25°C

3,367

0

0

0

0

Tetrachloromethane (Total)

D008

3 µg/l

689

0

<0.11

<0.16

0

Turbidity

A002

4 NTU

3,373

0

<0.1

0.37

0

Totals

21,856

2

Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Ammonium (Total)

A014

0.5 mg NH4/l

995

0

<0.05

0.1604

Chloride

D002A

250 mg Cl/l

767

0

19

83

(Confirmed)

C004A

0 number/100 ml

2,333

2

0

0

Coliform Bacteria (Indicator)

C001A

0 number/100 ml

9,664

15

0

0

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

3,372

N/A

0

105

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

3,373

0

480.7

784

Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

A006

6.5 – 9.5 pH Value

3,373

0

6.9

7.7

Residual Disinfectant – Total

C010

No abnormal change

9,665

N/A

0.09

0.98

Sulphate

A007

250 mg SO4/l

767

0

<11

118.32

Total Organic Carbon

A017

No abnormal change

675

N/A

<0.4

4.1

Totals

34,984

17

WSX (Wessex Water Services Ltd)

Report Data Range: For the whole year 2021

Table 1: Quality of water leaving service treatment works – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

Nitrite (Total)

A013B

0.1 mg NO2/l

441

0

<0.01

<0.01

0

Totals

441

0

Table 2: Quality of water leaving service treatment works – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

8,559

0

0

0

0

Total Coliforms (Confirmed)

C001

0 number/100 ml

8,559

0

0

0

0

Totals

17,118

0

Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

8,554

N/A

0

89

Residual Disinfectant – Free

C009

No abnormal change

8,590

N/A

0.29

0.9

Residual Disinfectant – Total

C010

No abnormal change

8,592

N/A

0.34

0.98

Turbidity – Indicator

A002A

1 NTU

8,559

0

<0.083

0.22

Totals

34,295

0

Table 4: Quality of water leaving service reservoirs – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of reservoirs failing standard

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

16,204

1

0

0

1

Total Coliforms (Confirmed)

C001

0 number/100 ml

16,204

4

0

0

0

Totals:

32,408

5

Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

16,192

N/A

0

>300

Residual Disinfectant – Free

C009

No abnormal change

16,204

N/A

0.13

0.62

Residual Disinfectant – Total

C010

No abnormal change

16,203

N/A

0.19

0.69

Totals:

48,599

0

Table 6: Quality of water leaving bulk supply points – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of supply point with failures

Bromate

F003

10 µg BrO3/l

339

0

<0.4

0.8

0

Totals

339

0

Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

441

0

0

0

Totals

441

0

Table 9: Quality of water at consumer’s tap (zones) – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of zones failing standard

1 2-Dichloroethane (Total)

F001

3 µg/l

488

0

<0.4

<0.4

0

Antimony

B008A

5 µg Sb/l

500

0

<0.2

0.2

0

Arsenic (Total)

B001A

10 µg As/l

500

0

<0.2

0.7

0

Benzene (Total)

F002

1 µg/l

488

0

<0.3

<0.3

0

Benzo[a]Pyrene (Total)

D007

0.01 µg/l

484

0

<0.0005

<0.001215

0

Boron

D005A

1 mg B/l

500

0

<0.03

0.09

0

Bromate

F003

10 µg BrO3/l

144

0

<0.4

3.855

0

Cadmium (Total)

B002

5 µg Cd/l

498

0

<0.1

<0.1

0

Chromium (Total)

B004

50 µg Cr/l

500

0

<1

<1

0

Copper (Total)

A024A

2 mg Cu/l

498

0

<0.01

0.7623

0

Cyanide (Total)

B003

50 µg CN/l

490

0

<1.2

<9

0

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

3,705

0

0

0

0

Enterococci (Confirmed)

C003

0 number/100 ml

498

0

0

0

0

Fluoride (Total)

A027

1.5 mg F/l

494

0

<0.138

0.651

0

Lead (10 – will apply 25.12.2013)

B007B

10 µg Pb/l

498

2

<0.1

4.816

2

Mercury (Total)

B005

1 µg Hg/l 

495

0

<0.05

<0.05

0

Nickel (Total) 

B006A 

20 µg Ni/l

498

2

<3

5.01

2

Nitrate (Total)

A012

50 mg NO3/l

590

0

<1.63718

41.8184

0

Nitrite – Consumer’s Taps

A013A

0.5 mg NO2/l

584

0

<0.01

<0.01

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

107

0

0

0.01176

0

Pesticides Aldrin

P002

0.03 µg/l

480

0

<0.005

<0.008

0

Pesticides Atrazine

P004

0.1 µg/l

16

0

<0.009

<0.009

0

Pesticides Bentazone

P006

0.1 µg/l

16

0

<0.003

0.008

0

Pesticides Clopyralid

P018

0.1 µg/l

8

0

<0.027

<0.027

0

Pesticides Dieldrin

P028

0.03 µg/l

475

0

<0.005

<0.009

0

Pesticides Heptachlor

P043

0.03 µg/l

480

0

<0.004

<0.006

0

Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

P044

0.03 µg/l

480

0

<0.011

<0.014

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

12

0

<0.006

<0.006

0

Pesticides Metaldehyde

P226

0.1 µg/l 

46

0

<0.01

<0.01

0

Pesticides Metazachlor

P203

0.1 µg/l 

8

0

<0.01

<0.01

0

Polycyclic Aromatic Hydrocarbons (Total by Calculation)

B011F

0.1 µg/l

457

0

0

0.00551

0

Selenium (Total)

B009

10 µg Se/l

495

0

<0.5

1.204

0

Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

D009B

10 µg/l

492

0

<0.5

<0.5

0

Trihalomethanes (Total by Calculation)

D011

100 µg/l

492

0

2.8465

42.8961

0

Totals

16,516

4

Table 10: Quality of water at consumer’s tap (zones) – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 percentile (representing a minimum)

99 percentile (representing a maximum)

No. of zones failing standard

Aluminium (Total)

A021

200 µg Al/l

1,382

0

<10

20

0

Colour

A001

20 mg/l Pt/Co

1,527

0

<0.6

<2.9

0

Iron (Total)

A022

200 µg Fe/l

1,382

1

<20

50

1

Manganese (Total)

A023

50 µg Mn/l

1,382

0

<1

5

0

Odour

A003

0 Dilution number at 25°C

1,438

0

0

0

0

Sodium (Total)

A009

200 mg Na/l

499

0

5.8

52

0

Taste (Taste Quant)

A004

0 Dilution number at 25°C

1,419

3

0

0

3

Tetrachloromethane (Total)

D008

3 µg/l

492

0

<0.23

0.2784

0

Turbidity

A002

4 NTU

1,529

0

<0.083

0.237

0

Totals

11,050

4

Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Ammonium (Total)

A014

0.5 mg NH4/l

584

0

<0.026924

0.0385

Chloride

D002A

250 mg Cl/l

500

0

12

50.97

Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

54

0

0

0

Coliform Bacteria (Indicator)

C001A

0 number/100 ml

3,705

2

0

0

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

1,525

N/A

0

64

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

1,529

0

112.158

699.178

Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

A006

6.5 – 9.5 pH Value

1,529

0

7.2

8.2

Residual Disinfectant – Free

C009

No abnormal change

3,725

N/A

0.07

0.61

Residual Disinfectant – Total

C010

No abnormal change

3,725

N/A

0.14

0.67

Sulphate

A007

250 mg SO4/l

500

0

11

104.96

Total Organic Carbon

A017

No abnormal change

495

N/A

<0.45

2.7

Totals

17,871

2

Portsmouth Water Limited – AMP8 Lead Strategy

Water Industry Act 1991 (as amended) (“the Act”): Section 19(1)(b)

Reference: PRT-2023-00009

Acceptance Notice:

The Drinking Water Inspectorate, on behalf of the Secretary of State:

  1. Is satisfied that Portsmouth Water Ltd “the Company” in supplying water from all company water supply zones which may be at risk of exceeding the standards for Lead. This means that the Company is likely to contravene its duty in respect of supplying water which meets the Regulations under Section 68(1)(a) of the Water Industry Act 1991 and meets the requirement set in regulation 4(2)(c) of the Water Supply (Water Quality) Regulations 2016 (as amended) (“the Regulations”).
  2. Has notified the Company on 8 November 2023 that the Secretary of State is considering making in relation to the company an enforcement order under Section 18 of the Act.
  3. Notes that the Company has on 5 March 2023 given a new undertaking under Section 19 (1) (b) of the Act, to take the following steps by the dates shown.

4. Steps to be taken:

  1. Ensure that the Lead parameter has been assessed as a hazard as part of the regulation 27 Risk Assessment for the supply system that includes the water supply zones listed in the Annex to this Schedule according to a Drinking Water Safety Plan approach. Ensure that regulation 28 documents are reviewed, and updates provided as necessary.
    Date: Ongoing for the duration of the undertaking
  2. Keep under review the company’s strategy for the protection of public health and for compliance with drinking water quality standards with respect to lead.
    Date: Ongoing for the duration of the undertaking
  1. A programme of lead supply pipe replacement in the highest risk priority cases in 60 in schools/nurseries within the Company’s Supply area. The replacement will be to the first tap within the institution’s building.
    Date: 31 March 2030
  2. Replace of the company’s lead communications pipe where an internal threshold of 5μg/l is not met.
    Date: Ongoing for the duration of the undertaking
  3. Continue to proactively replace any company-owned lead communication pipes on properties where lead is identified during the mains renewal programme.
    Date: Ongoing for the duration of the undertaking
  4. Continue to replace Portsmouth Water Lead pipework when customers replace their part of the lead service pipe when customers replace their part of lead service pipe.
    Date: Ongoing for the duration of the undertaking
  5. Continue the intensive lead sampling programme in the key water supply zones.
    Date: Ongoing for the duration of the undertaking
  6. Continue to raise customer awareness on the risk of lead via the website and direct correspondence following operational activities.
    Date: Ongoing for the duration of the undertaking
  7. Produce a plan to achieve lead free drinking water supplies.
    Date: 31 December 2027
  8. Develop and submit the company’s draft Lead reduction plans for AMP9, demonstrating the required ramp-up pipe replacement rate.
    Date: 31 August 2027

Reporting:

d. At regular intervals provide DWI with reports on progress made with carrying out the steps set out in the Action Plan. Reports to include at least the following details:

a) All data from the monitoring of treated water in the distribution systems named in the annex.

b) Details of the remedial steps that comprise the programme of work including commencement and completion dates for investigations, design, tendering, construction, and commissioning.

c) Current state of progress with the steps referred to in (b) above;

d) A statement of implications of any slippage of the programme and details of activities planned to bring programme back on target.

e) Whether the company has any other reason to believe it may not be able to meet any of the key dates set out in this Schedule of Work.
Date: By 31 January each year that the undertaking is in place

e. Continue to monitor at an enhanced frequency for Lead for a period of 12 months following commissioning of any work associated with the Action Plan to demonstrate the effectiveness of the remedial measures taken.
Date: 31 March 2031

f. Provide a final report to DWI on the efficacy of the remedial measures taken as part of the lead strategy. Include as evidence for closure for this scheme appropriate documentation to confirm that the actions set out in this Schedule of Work have been taken and that the company’s lead strategy is in place.
Date: 30 April 2031

Further Details of this Acceptance Notice:

  1. The Secretary of State is satisfied that Portsmouth Water Limited has given and is complying with an undertaking to take all such steps as appear to the Secretary of State for the time being to be appropriate to secure or facilitate compliance with the requirement of regulation 4(2)(c) of the Water Supply (Water Quality) Regulations 2016 (as amended).

Authorised by the Secretary of State to sign in that behalf

Nicholas Adjei
Deputy Chief Inspector, Drinking Water Inspectorate
14 March 2024
Reference: PRT-2023-00009

YKS (Yorkshire Water Services Ltd)

Report Data Range: For the whole year 2021

Table 1: Quality of water leaving service treatment works – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

Nitrite (Total)

A013B

0.1 mg NO2/l

2,221

0

<0.002

0.002

0

Totals

2,221

0

Table 2: Quality of water leaving service treatment works – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

14,071

0

0

0

0

Total Coliforms (Confirmed)

C001

0 number/100 ml

14,071

6

0

0

6

Totals

28,142

6

Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

14,071

N/A

0

2

Residual Disinfectant – Free

C009

No abnormal change

14,071

N/A

0.0272

0.95

Residual Disinfectant – Total

C010

No abnormal change

14,071

N/A

0.1

1.06

Turbidity – Indicator

A002A

1 NTU

14,071

0

<0.13

0.42

Totals

56,284

0

Table 4: Quality of water leaving service reservoirs – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of reservoirs failing standard

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

17,660

1

0

0

1

Total Coliforms (Confirmed)

C001

0 number/100 ml

17,660

9

0

0

0

Totals:

35,320

10

Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

17,660

N/A

0

9

Residual Disinfectant – Free

C009

No abnormal change

17,660

N/A

0

0.79

Residual Disinfectant – Total

C010

No abnormal change

17,660

N/A

0.05

0.88

Totals:

52,980

0

Table 6: Quality of water leaving bulk supply points – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of supply point with failures

Boron

D005A

1 mg B/l

96

0

0.00639

<0.032

0

Cyanide (Total)

B003

50 µg CN/l

96

0

<1.2

35

0

Fluoride (Total)

A027

1.5 mg F/l

96

0

<0.04

0.12

0

Mercury (Total)

B005

1 µg Hg/l 

96

0

<0.04

0.12

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

96

0

0

0.09

0

Pesticides 1,1,1-trichloro-2,2-ethane pp’-DDT

P125

0.1 µg/l

96

0

<0.004

<0.005

0

Pesticides 1,1-dichloro-2,2-bis-ethane pp’-DDE

P124

0.1 µg/l

96

0

<0.005

<0.005

0

Pesticides 2 4-D

P020

0.1 µg/l

96

0

<0.012

0.018

0

Pesticides 2 4-DB

P082

0.1 µg/l

96

0

<0.017

<0.018

0

Pesticides 2,4,5-T

P076

0.1 µg/l

96

0

<0.011

<0.016

0

Pesticides Aldrin

P002

0.03 µg/l

96

0

<0.005

<0.008

0

Pesticides Atrazine

P004

0.1 µg/l

96

0

<0.004

<0.008

0

Pesticides Bentazone

P006

0.1 µg/l

96

0

<0.002

<0.004

0

Pesticides Bromacil

P086

0.1 µg/l

96

0

<0.007

<0.009

0

Pesticides Bromoxynil

P008

0.1 µg/l

96

0

<0.009

<0.009

0

Pesticides Carbetamide 

P010

0.1 µg/l

96

0

<0.008

0.012

0

Pesticides Chlormequat

P163

0.1 µg/l

96

0

<0.003

<0.003

0

Pesticides Chlorpropham

P016

0.1 µg/l

96

0

<0.012

<0.014

0

Pesticides Chlorpyrifos (Chlorpyriphos Ethyl)

P017

0.1 µg/l

96

0

<0.016

<0.016

0

Pesticides Chlortoluron

P014

0.1 µg/l

96

0

<0.006

<0.007

0

Pesticides Clomazone

P246

0.1 µg/l

96

0

<0.005

<0.008

0

Pesticides Clopyralid

P018

0.1 µg/l

96

0

<0.011

0.034

0

Pesticides Cyanazine

P092

0.1 µg/l

96

0

<0.006

<0.007

0

Pesticides Cypermethrin

P094

0.1 µg/l

96

0

<0.005

<0.008

0

Pesticides Cyproconazole

P207

0.1 µg/l

96

0

<0.007

<0.008

0

Pesticides Diazinon

P024

0.1 µg/l

96

0

<0.006

<0.007

0

Pesticides Dicamba

P025

0.1 µg/l

96

0

<0.012

<0.014

0

Pesticides Dichlobenil

P098

0.1 µg/l

96

0

<0.004

<0.005

0

Pesticides Dichlorodiphenyldichlorethane pp’-DDD TDE

P123

0.1 µg/l

96

0

<0.005

<0.005

0

Pesticides Dichlorodiphenyldichloroethyle op’-DDE

P115

0.1 µg/l

96

0

<0.005

<0.005

0

Pesticides Dichlorprop

P026

0.1 µg/l

96

0

<0.011

<0.017

0

Pesticides Dieldrin

P028

0.03 µg/l

96

0

<0.005

<0.009

0

Pesticides Difenconazole

P247

0.1 µg/l

96

0

<0.007

<0.009

0

Pesticides Diflufenican

P157

0.1 µg/l

96

0

<0.007

<0.009

0

Pesticides Diuron

P032

0.1 µg/l

96

0

<0.009

<0.01

0

Pesticides Epoxyconazole

P217

0.1 µg/l

96

0

<0.005

<0.006

0

Pesticides EPTC

P035

0.1 µg/l

96

0

<0.01

<0.013

0

Pesticides Flufenacet

P230

0.1 µg/l

96

0

<0.008

0.034

0

Pesticides Fluroxypyr

P040

0.1 µg/l

96

0

<0.009

<0.012

0

Pesticides Flurtamone

P248

0.1 µg/l

96

0

<0.007

<0.014

0

Pesticides Flusilazole

P159

0.1 µg/l

96

0

<0.006

<0.007

0

Pesticides Flutriafol

P039

0.1 µg/l

96

0

<0.005

<0.005

0

Pesticides Gamma-HCH (Lindane)

P041

0.1 µg/l

96

0

<0.005

0.006

0

Pesticides Heptachlor

P043

0.03 µg/l

96

0

<0.004

<0.005

0

Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

P044

0.03 µg/l

96

0

<0.006

<0.007

0

Pesticides Imazapyr

P160

0.1 µg/l

96

0

<0.004

<0.009

0

Pesticides Ioxynil

P049

0.1 µg/l

96

0

<0.007

<0.009

0

Pesticides Isoproturon

P048

0.1 µg/l

96

0

<0.005

<0.006

0

Pesticides Linuron

P051

0.1 µg/l

96

0

<0.007

<0.012

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

96

0

<0.008

0.013

0

Pesticides Mecoprop-P

P249

0.1 µg/l

96

0

<0.007

<0.009

0

Pesticides Mepiquat Chloride

P280

0.1 µg/l

96

0

<0.004

<0.004

0

Pesticides Metaldehyde

P226

0.1 µg/l

96

0

<0.007

0.015

0

Pesticides Metazachlor

P203

0.1 µg/l

96

0

<0.006

<0.007

0

Pesticides Monuron

P113

0.1 µg/l

96

0

<0.007

<0.007

0

Pesticides op’-DDD (TDE)

P114

0.1 µg/l

96

0

<0.005

<0.005

0

Pesticides Oxadixyl

P154

0.1 µg/l

96

0

<0.01

<0.024

0

Pesticides Pendimethalin

P118

0.1 µg/l

96

0

<0.009

<0.02

0

Pesticides Propachlor

P126

0.1 µg/l

96

0

<0.006

<0.008

0

Pesticides Propham

P067

0.1 µg/l

96

0

<0.007

<0.009

0

Pesticides Propiconazole

P068

0.1 µg/l

96

0

<0.007

<0.007

0

Pesticides Propyzamide

P071

0.1 µg/l

96

0

<0.007

0.033

0

Pesticides Prosulfocarb

P243

0.1 µg/l

96

0

<0.007

<0.009

0

Pesticides Quinmerac

P224

0.1 µg/l

96

0

<0.006

0.007

0

Pesticides Simazine

P073

0.1 µg/l

96

0

<0.004

<0.005

0

Pesticides Tebuconazole

P177

0.1 µg/l

96

0

<0.005

<0.009

0

Pesticides Tri-allate

P079

0.1 µg/l

96

0

<0.005

<0.006

0

Pesticides Trichloro-2(2chlorophenyl)2eth op’-DDT

P116

0.1 µg/l

96

0

<0.004

<0.005

0

Pesticides Triclopyr

P131

0.1 µg/l

96

0

<0.015

<0.028

0

Pesticides Trietazine

P132

0.1 µg/l

96

0

<0.004

<0.006

0

Totals

6,720

0

Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Chloride

D002A

250 mg Cl/l

96

0

5.6

36.7

Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

481

0

0

0

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

5,959

0

111.6

725

Total Organic Carbon

A017

No abnormal change

96

N/A

0.8

2.38

Totals

6,632

0

Table 9: Quality of water at consumer’s tap (zones) – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of zones failing standard

1 2-Dichloroethane (Total)

F001

3 µg/l

712

0

<0.16

<0.16

0

Antimony

B008A

5 µg Sb/l

712

0

0.0313

0.2387

0

Arsenic (Total)

B001A

10 µg As/l

712

0

0.07

1.6787

0

Benzene (Total)

F002

1 µg/l

712

0

<0.06

<0.09

0

Benzo[a]Pyrene (Total)

D007

0.01 µg/l

712

0

<0.00057

<0.00057

0

Boron

D005A

1 mg B/l

592

0

0.0088128

0.046791

0

Bromate

F003

10 µg BrO3/l

712

0

<0.2

3.587

0

Cadmium (Total)

B002

5 µg Cd/l

712

0

<0.01

<0.05

0

Chromium (Total)

B004

50 µg Cr/l

712

0

<0.04

0.9187

0

Copper (Total)

A024A

2 mg Cu/l

712

0

0.0005

0.34127

0

Cyanide (Total)

B003

50 µg CN/l

577

0

<1.2

19.66

0

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

12,696

0

0

0

0

Enterococci (Confirmed)

C003

0 number/100 ml

712

0

0

0

0

Fluoride (Total)

A027

1.5 mg F/l

592

0

<0.04

0.16

0

Lead (10 – will apply 25.12.2013)

B007B

10 µg Pb/l

712

5

<0.02

6.6131

5

Mercury (Total)

B005

1 µg Hg/l 

576

0

<0.04

<0.06

0

Nickel (Total) 

B006A 

20 µg Ni/l

712

4

0.1713

8.971

3

Nitrate (Total)

A012

50 mg NO3/l

1,412

0

<2.11

42.374

0

Nitrite – Consumer’s Taps

A013A

0.5 mg NO2/l

1,412

0

<0.002

0.26748

0

Nitrite/Nitrate formula

A013C

1 mg/l

1,412

0

0

0.8487

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

576

0

0

0.06846

0

Pesticides 1,1,1-trichloro-2,2-ethane pp’-DDT

P125

0.1 µg/l

576

0

<0.004

<0.005

0

Pesticides 1,1-dichloro-2,2-bis-ethane pp’-DDE

P124

0.1 µg/l

576

0

<0.005

<0.005

0

Pesticides 2 4-D

P020

0.1 µg/l

576

0

<0.012

<0.012

0

Pesticides 2 4-DB

P082

0.1 µg/l

576

0

<0.017

<0.018

0

Pesticides 2,4,5-T

P076

0.1 µg/l

576

0

<0.011

<0.016

0

Pesticides Aldrin

P002

0.03 µg/l

576

0

<0.005

<0.008

0

Pesticides Atrazine

P004

0.1 µg/l

576

0

<0.004

0.038

0

Pesticides Bentazone

P006

0.1 µg/l

576

0

<0.002

0.011

0

Pesticides Bromacil

P086

0.1 µg/l

576

0

<0.007

<0.009

0

Pesticides Bromoxynil

P008

0.1 µg/l

576

0

<0.009

<0.009

0

Pesticides Carbetamide

P010

0.1 µg/l

576

0

<0.008

<0.01

0

Pesticides Chlormequat

P163

0.1 µg/l

576

0

<0.003

<0.003

0

Pesticides Chlorpropham

P016

0.1 µg/l

576

0

<0.012

<0.014

0

Pesticides Chlorpyrifos (Chlorpyriphos Ethyl)

P017

0.1 µg/l

576

0

<0.016

<0.016

0

Pesticides Chlortoluron

P014

0.1 µg/l

576

0

<0.006

<0.007

0

Pesticides Clomazone

P246

0.1 µg/l

576

0

<0.005

<0.008

0

Pesticides Clopyralid

P018

0.1 µg/l

576

0

<0.011

0.02769

0

Pesticides Cyanazine

P092

0.1 µg/l

576

0

<0.006

<0.007

0

Pesticides Cypermethrin

P094

0.1 µg/l

576

0

<0.005

<0.008

0

Pesticides Cyproconazole

P207

0.1 µg/l

576

0

<0.007

<0.008

0

Pesticides Diazinon

P024

0.1 µg/l

576

0

<0.006

<0.007

0

Pesticides Dicamba

P025

0.1 µg/l

576

0

<0.012

<0.014

0

Pesticides Dichlobenil

P098

0.1 µg/l

576

0

<0.004

<0.005

0

Pesticides Dichlorodiphenyldichlorethane pp’-DDD TDE

P123

0.1 µg/l

576

0

<0.005

<0.005

0

Pesticides Dichlorodiphenyldichloroethyle op’-DDE

P115

0.1 µg/l

576

0

<0.005

<0.005

0

Pesticides Dichlorprop

P026

0.1 µg/l

576

0

<0.011

<0.017

0

Pesticides Dieldrin

P028

0.03 µg/l

576

0

<0.005

<0.009

0

Pesticides Difenconazole

P247

0.1 µg/l

576

0

<0.007

<0.009

0

Pesticides Diflufenican

P157

0.1 µg/l

576

0

<0.007

<0.009

0

Pesticides Diuron

P032

0.1 µg/l

576

0

<0.009

<0.01

0

Pesticides Epoxyconazole

P217

0.1 µg/l

576

0

<0.005

<0.006

0

Pesticides EPTC

P035

0.1 µg/l

576

0

<0.01

<0.013

0

Pesticides Flufenacet

P230

0.1 µg/l

576

0

<0.008

0.029

0

Pesticides Fluroxypyr

P040

0.1 µg/l

576

0

<0.009

<0.012

0

Pesticides Flurtamone

P248

0.1 µg/l

576

0

<0.007

<0.007

0

Pesticides Flusilazole

P159

0.1 µg/l

576

0

<0.006

<0.007

0

Pesticides Flutriafol

P039

0.1 µg/l

576

0

<0.005

<0.005

0

Pesticides Gamma-HCH (Lindane)

P041

0.1 µg/l

576

0

<0.005

<0.006

0

Pesticides Heptachlor

P043

0.03 µg/l

576

0

<0.004

<0.005

0

Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

P044

0.03 µg/l

576

0

<0.006

<0.007

0

Pesticides Imazapyr

P160

0.1 µg/l

576

0

<0.004

<0.009

0

Pesticides Ioxynil

P049

0.1 µg/l

576

0

<0.007

<0.009

0

Pesticides Isoproturon

P048

0.1 µg/l

576

0

<0.005

<0.006

0

Pesticides Linuron

P051

0.1 µg/l

576

0

<0.007

<0.012

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

576

0

<0.008

<0.012

0

Pesticides Mecoprop-P

P249

0.1 µg/l

576

0

<0.007

<0.009

0

Pesticides Mepiquat Chloride

P280

0.1 µg/l

576

0

<0.004

<0.004

0

Pesticides Metaldehyde

P226

0.1 µg/l 

576

0

<0.007

0.02023

0

Pesticides Metazachlor

P203

0.1 µg/l 

576

0

<0.006

<0.00746

0

Pesticides Monuron

P113

0.1 µg/l

576

0

<0.007

<0.007

0

Pesticides op’-DDD (TDE)

P114

0.1 µg/l

576

0

<0.005

<0.005

0

Pesticides Oxadixyl

P154

0.1 µg/l

576

0

<0.01

<0.012

0

Pesticides Pendimethalin

P118

0.1 µg/l

576

0

<0.009

0.02

0

Pesticides Propachlor

P126

0.1 µg/l

576

0

<0.006

<0.008

0

Pesticides Propham

P067

0.1 µg/l

576

0

<0.007

<0.009

0

Pesticides Propiconazole

P068

0.1 µg/l

576

0

<0.007

<0.007

0

Pesticides Propyzamide

P071

0.1 µg/l

576

0

<0.007

0.01823

0

Pesticides Prosulfocarb

P243

0.1 µg/l

576

0

<0.007

<0.009

0

Pesticides Quinmerac

P244

0.1 µg/l

576

0

<0.006

0.008

0

Pesticides Simazine

P073

0.1 µg/l

576

0

<0.004

0.006

0

Pesticides Tebuconazole

P177

0.1 µg/l

576

0

<0.005

<0.009

0

Pesticides Tri-allate

P079

0.1 µg/l

576

0

<0.005

<0.006

0

Pesticides Trichloro-2(2chlorophenyl)2eth op’-DDT

P116

0.1 µg/l

576

0

<0.004

<0.005

0

Pesticides Triclopyr

P131

0.1 µg/l

576

0

<0.015

<0.028

0

Pesticides Trietazine

P132

0.1 µg/l

576

0

<0.004

<0.006

0

Polycyclic Aromatic Hydrocarbons (Total by Calculation)

B011F

0.1 µg/l

712

0

0

0.001

0

Selenium (Total)

B009

10 µg Se/l

712

0

<0.08

0.8474

0

Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

D009B

10 µg/l

712

0

0

0

0

Trihalomethanes (Total by Calculation)

D011

100 µg/l

712

1

3.0113

55.224

1

Totals

68,677

10

Table 10: Quality of water at consumer’s tap (zones) – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 percentile (representing a minimum)

99 percentile (representing a maximum)

No. of zones failing standard

Aluminium (Total)

A021

200 µg Al/l

4,340

1

<6.9

27.254

1

Colour

A001

20 mg/l Pt/Co

4,340

0

<2.9

<3

0

Iron (Total)

A022

200 µg Fe/l

4,340

18

<3.72

115

14

Manganese (Total)

A023

50 µg Mn/l

4,340

1

<0.3

7.8631

1

Odour

A003

0 Dilution number at 25°C

4,340

3

0

0

3

Sodium (Total)

A009

200 mg Na/l

712

0

5.37

40.322

0

Taste (Taste Quant)

A004

0 Dilution number at 25°C

4,340

1

0

0

1

Tetrachloromethane (Total)

D008

3 µg/l

712

0

<0.13

<0.16

0

Turbidity

A002

4 NTU

4,340

1

<0.13

0.4759

1

Totals

31,804

25

Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Ammonium (Total)

A014

0.5 mg NH4/l

4,340

0

<0.008

0.17359

Chloride

D002A

250 mg Cl/l

592

0

6.1

52.114

Coliform Bacteria (Indicator)

C001A

0 number/100 ml

12,696

15

0

0

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

4,341

N/A

0

10

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

4,340

0

112.41

709

Gross Alpha

F004

0.1 Bq/l

72

0

<0.021

0.096

Gross Beta

F005

1 Bq/l

72

0

0.036

0.125

Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

A006

6.5 – 9.5 pH Value

4,340

0

7

8.02

Residual Disinfectant – Free

C009

No abnormal change

12,696

N/A

0.01

0.74

Residual Disinfectant – Total

C010

No abnormal change

12,696

N/A

0.05

0.83

Sulphate

A007

250 mg SO4/l

712

0

19.039

154.74

Total Organic Carbon

A017

No abnormal change

592

N/A

<0.7

2.4442

Totals

57,489

15

Water supply arrangements

Company Assets

Number of treatment works

92

Number of service reservoirs 

157

Number of water supply zones

89

Length of mains pipe (km)

16,800km

Population Served

Population Supplied

3,797,000

Number of local authorities

41

Water Supplied

Water Supplied (l/day)

950,608,000

Percentage from surface sources

40%

Percentage of ground sources

55%

Percentage from mixed sources

5%

Area of supply

Cambridge, Huntingdonshire

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

961

0.25

2020

897

0.24

2021

900

0.24

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

3,066

0.81

2020

3,319

0.88

2021

3,036

0.80

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

No consumers of Cambridge Water plc directly contacted DWI in 2021.

SWB (South West and Bournemouth Water)

Report Data Range: For the whole year 2021

Table 1: Quality of water leaving service treatment works – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

Nitrite (Total)

A013B

0.1 mg NO2/l

1,199

0

<0.015

0.038

0

Totals

1,199

0

Table 2: Quality of water leaving service treatment works – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of works with failures

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

8,466

0

0

0

0

Total Coliforms (Confirmed)

C001

0 number/100 ml

8,466

7

0

0

0

Totals

16,932

7

Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

8,467

N/A

0

2

Residual Disinfectant – Free

C009

No abnormal change

8,473

N/A

0.03

1.15

Residual Disinfectant – Total

C010

No abnormal change

8,473

N/A

0.23

1.2

Turbidity – Indicator

A002A

1 NTU

8,464

0

<0.07

0.25

Totals

33,877

0

Table 4: Quality of water leaving service reservoirs – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of reservoirs failing standard

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

14,168

1

0

0

1

Total Coliforms (Confirmed)

C001

0 number/100 ml

14,168

7

0

0

0

Totals:

28,336

8

Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

14,171

N/A

0

49

Residual Disinfectant – Free

C009

No abnormal change

14,172

N/A

0.02

0.9

Residual Disinfectant – Total

C010

No abnormal change

14,172

N/A

0.12

0.94

Totals:

42,515

0

Table 6: Quality of water leaving bulk supply points – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of supply point with failures

Boron

D005A

1 mg B/l

376

0

0.0014179

0.027215

0

Cyanide (Total)

B003

50 µg CN/l

330

0

<2.7

7.187

0

Fluoride (Total)

A027

1.5 mg F/l

376

0

<0.011

0.20646

0

Mercury (Total)

B005

1 µg Hg/l 

376

0

<0.04

0.05167

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

430

0

0

0.034

0

Pesticides 2 4-D

P020

0.1 µg/l

388

0

<0.01

<0.01

0

Pesticides 2 4-DB

P082

0.1 µg/l

388

0

<0.007

<0.014

0

Pesticides Asulam

P133

0.1 µg/l

388

0

<0.012

<0.02664

0

Pesticides Atrazine

P004

0.1 µg/l

386

0

<0.007

0.034

0

Pesticides Azoxystrobin

P227

0.1 µg/l

386

0

<0.005

<0.005

0

Pesticides Bentazone

P006

0.1 µg/l

388

0

<0.002

<0.007

0

Pesticides Boscalid

P231

0.1 µg/l

386

0

<0.007

<0.007

0

Pesticides Bromoxynil

P008

0.1 µg/l

388

0

<0.006

<0.012

0

Pesticides Carbendazim (Total)

150

0.1 µg/l

386

0

<0.003

<0.003

0

Pesticides Chlorpyrifos (Chlorpyriphos Ethyl)

P017

0.1 µg/l

382

0

<0.002

<0.00217

0

Pesticides Chlortoluron

P014

0.1 µg/l

386

0

<0.005

<0.005

0

Pesticides Clopyralid

P018

0.1 µg/l

388

0

<0.009

<0.01998

0

Pesticides Cyprodinil

P228

0.1 µg/l

381

0

<0.01

<0.01018

0

Pesticides Cyromazine

P223

0.1 µg/l

386

0

<0.012

<0.012

0

Pesticides Diazinon

P024

0.1 µg/l

395

0

<0.007

<0.00704

0

Pesticides Dicamba

P025

0.1 µg/l

388

0

<0.01

<0.02

0

Pesticides Dichlobenil

P098

0.1 µg/l

371

0

<0.003

<0.00328

0

Pesticides Dichlorprop

P026

0.1 µg/l

388

0

<0.009

<0.018

0

Pesticides Dieldrin

P028

0.03 µg/l

396

0

<0.004

<0.00403

0

Pesticides Diflufenican

P157

0.1 µg/l

381

0

<0.003

<0.00318

0

Pesticides Diuron

P032

0.1 µg/l

386

0

<0.007

<0.007

0

Pesticides Epoxyconazole

P217

0.1 µg/l

384

0

<0.016

<0.0163

0

Pesticides Fenpropimorph

P037

0.1 µg/l

392

0

<0.003

<0.00307

0

Pesticides Fluroxypyr

P040

0.1 µg/l

388

0

<0.007

<0.014

0

Pesticides Gamma-HCH (Lindane)

P041

0.1 µg/l

385

0

<0.011

<0.01156

0

Pesticides Ioxynil

P049

0.1 µg/l

388

0

<0.004

<0.008

0

Pesticides Isoproturon

P048

0.1 µg/l

386

0

<0.004

<0.004

0

Pesticides Linuron

P051

0.1 µg/l

386

0

<0.012

<0.012

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

387

0

<0.006

<0.01212

0

Pesticides MCPB

P055

0.1 µg/l

388

0

<0.008

<0.008

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

388

0

<0.007

<0.014

0

Pesticides Metaldehyde

P226

0.1 µg/l 

295

0

<0.001

0.003

0

Pesticides Metamitron

P194

0.1 µg/l 

381

0

<0.01

<0.01

0

Pesticides Pendimethalin

P118

0.1 µg/l

395

0

<0.003

<0.00304

0

Pesticides Pentachlorophenol

P060

0.1 µg/l

388

0

<0.007

<0.007

0

Pesticides Picloram (Total)

P122

0.1 µg/l

388

0

<0.004

<0.01699

0

Pesticides Propamocarb

P238

0.1 µg/l

381

0

<0.009

<0.009

0

Pesticides Propyzamide

P071

0.1 µg/l

386

0

<0.005

<0.005

0

Pesticides Quinmerac

P224

0.1 µg/l

388

0

<0.002

<0.025

0

Pesticides Simazine

P073

0.1 µg/l

386

0

<0.007

<0.007

0

Pesticides Tebuconazole

P177

0.1 µg/l

382

0

<0.007

<0.007

0

Pesticides Triclopyr

P131

0.1 µg/l

388

0

<0.004

<0.00844

0

Totals

18,030

0

Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Chloride

D002A

250 mg Cl/l

375

0

7.632

40.24

Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

2,785

0

0

0

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

2,256

0

75.071

512.22

Sulphate

A007

250 mg SO4/l

374

0

<2.4

45.55

Total Organic Carbon

A017

No abnormal change

372

N/A

<0.42

5.5603

Totals

6,162

0

Table 9: Quality of water at consumer’s tap (zones) – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of supply point with failures

1 2-Dichloroethane (Total)

F001

3 µg/l

407

0

<0.2

<0.2

0

Antimony

B008A

5 µg Sb/l

406

0

<0.05

0.26

0

Arsenic (Total)

B001A

10 µg As/l

406

0

<0.62

0.8679

0

Benzene (Total)

F002

1 µg/l

407

0

<0.2

<0.2

0

Benzo[a]Pyrene (Total)

D007

0.01 µg/l

458

1

<0.0005

<0.0025

1

Bromate

F003

10 µg BrO3/l

401

0

<0.15

3.4

0

Cadmium (Total)

B002

5 µg Cd/l

406

0

<0.06

0.07751

0

Chromium (Total)

B004

50 µg Cr/l

406

0

<0.8

<0.89207

0

Copper (Total)

A024A

2 mg Cu/l

394

0

<0.0019

0.63905

0

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

5,638

0

0

0

0

Enterococci (Confirmed)

C003

0 number/100 ml

407

0

0

0

0

Lead (10 – will apply 25.12.2013)

B007B

10 µg Pb/l

394

1

<0.08

2.582

1

Nickel (Total)

B006A

20 µg Ni/l

394

1

<3.3

7.179

1

Nitrate (Total)

A012

50 mg NO3/l

636

0

<1.6

34.3019

0

Nitrite – Consumer’s Taps

A013A

0.5 mg NO2/l

636

0

<0.015

0.20678

0

Nitrite/Nitrate formula

A013C

1 mg/l

636

0

0

0.6863

0

Polycyclic Aromatic Hydrocarbons (Total by Calculation)

B011F

0.1 µg/l

407

0

0

0.007

0

Selenium (Total)

B009

10 µg Se/l

305

0

<0.52

1

0

Trihalomethanes (Total by Calculation)

D011

100 µg/l

407

0

0

0.6

0

Trihalomethanes (Total by Calculation)

D011

100 µg/l

407

0

1.88

63.972

0

Totals

14,058

3

Table 10: Quality of water at consumer’s tap (zones) – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 percentile (representing a minimum)

99 percentile (representing a maximum)

No. of zones failing standard

Aluminium (Total)

A021

200 µg Al/l

2,048

1

<4.9

38.953

1

Colour

A001

20 mg/l Pt/Co

2,049

0

<0.8

3.4

0

Iron (Total)

A022

200 µg Fe/l

2,047

1

<7.6

70.848

1

Manganese (Total)

A023

50 µg Mn/l

2,048

0

<0.3

6.4402

0

Odour

A003

0 Dilution number at 25°C

2,061

0

0

0

0

Sodium (Total)

A009

200 mg Na/l

406

0

4.521

32

0

Taste (Taste Quant)

A004

0 Dilution number at 25°C

2,060

0

0

0

0

Tetrachloromethane (Total)

D008

3 µg/l

407

0

<0.2

<0.2

0

Turbidity

A002

4 NTU

2,050

0

<0.07

0.28

0

Totals

15,176

2

Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Ammonium (Total)

A014

0.5 mg NH4/l

2,041

0

<0.003

0.14

Coliform Bacteria (Indicator)

C001A

0 number/100 ml

5,638

9

0

0

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

5,639

N/A

0

23

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

372

0

386.92

562.54

Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

A006

6.5 – 9.5 pH Value

2,048

0

7.2

8.8

Residual Disinfectant – Free

C009

No abnormal change

5,640

N/A

0.02

0.84

Residual Disinfectant – Total

C010

No abnormal change

5,640

N/A

0.1141

0.9059

Totals

27,018

9

Drinking Water Quality – Advisory Group 

The Water Supply (Water Quality) Regulations 2016 (England) and 2018 (Wales), Private Water Supplies (England) Regulations 2016 and Private Water Supplies (Wales) Regulations 2017 include schedules of parameters which water companies are required to monitor to verify drinking water safety. As new risks emerge, such as from industrial contaminants and due to changes in environmental waters, and scientific evidence evolves, these standards require periodic review to ensure robust protection of public health.

The Drinking Water Inspectorate has assembled a group of experts to review and provide recommendations on parameters to ensure drinking water quality in England and Wales remains of the highest standards. The review includes updating, removing or incorporating additional standards as required to protect public health and maintain consumer confidence in drinking water. Using scientific evidence, including World Health Organisation guideline values, the advisory group will provide recommendations to the Chief Inspector who will advise ministers.

The recommendations and full report of the advisory group (dated December 2024) on future drinking water standards can be viewed below.

Advisory group members are listed below, although the Inspectorate will invite additional specialists from time to time when required.

UK Health Security Agency 

Dr Ian Barnabas (Northumbrian Water Limited) 

Dr Austen Buck (Water Research Centre Ltd)

Dr Sarah Bull (Tara Consultancy) 

Ms Sharon Evans (Dŵr Cymru Welsh Water) 

Professor John Fawell (Cranfield University) 

Dr Emma Goslan (Cranfield University) 

Professor Nigel Graham (Emeritus Professor of Imperial College London) 

Professor Peter Jarvis (Cranfield University) 

Mr Robert Pitchers (Independent consultant) 

Dr Katherine Pond (University of Surrey) 

ALE (Albion Eco Ltd)

Report Data Range: For the whole year 2021

Table 9: Quality of water at consumer’s tap (zones) – European Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 Percentile (representing a minimum)

99 Percentile (representing a maximum)

No. of zones failing standard

1 2-Dichloroethane (Total)

F001

3 µg/l

4

0

<0.16

<0.16

0

Antimony

B008A

5 µg Sb/l

4

0

0.08

0.11

0

Arsenic (Total)

B001A

10 µg As/l

4

0

<0.15

0.18

0

Benzene (Total)

F002

1 µg/l

4

0

<0.06

<0.06

0

Benzo[a]Pyrene (Total)

D007

0.01 µg/l

4

0

<0.00057

<0.00057

0

Boron

D005A

1 mg B/l

4

0

<0.032

<0.32

0

Bromate

F003

10 µg BrO3/l

4

0

<0.15

<0.15

0

Cadmium (Total)

B002

5 µg Cd/l

4

0

<0.03

<0.03

0

Chromium (Total)

B004

50 µg Cr/l

4

0

<0.18

<0.18

0

Copper (Total)

A024A

2 mg Cu/l

4

0

0.0193

0.0409

0

Cyanide (Total)

B003

50 µg CN/l

4

0

<5.5

<5.5

0

E coli (faecal coliforms Confirmed)

C002

0 number/100 ml

12

0

0

0

0

Enterococci (Confirmed)

C003

0 number/100 ml

4

0

0

0

0

Fluoride (Total)

A027

1.5 mg F/l

4

0

<0.04

0.06

0

Lead (10 – will apply 25.12.2013)

B007B

10 µg Pb/l

4

0

0.27

3.84

0

Mercury (Total)

B005

1 µg Hg/l 

4

0

<0.06

<0.06

0

Nickel (Total) 

B006A 

20 µg Ni/l

4

0

0.61

0.92

0

Nitrate (Total)

A012

50 mg NO3/l

4

0

4.38

10.8

0

Nitrite – Consumer’s Taps

A013A

0.5 mg NO2/l

4

0

<0.002

0.007

0

Nitrite/Nitrate formula

A013C

1 mg/l

4

0

0.09

0.22

0

Pesticides (Total by Calculation)

B010

0.5 µg/l

4

0

0

0.01

0

Pesticides 2,3,6-Tba

P074

0.1 µg/l

4

0

<0.009

<0.01

0

Pesticides Asulam

P133

0.1 µg/l

4

0

<0.008

<0.014

0

Pesticides Benazolin (Total)

P138

0.1 µg/l

4

0

<0.01

<0.011

0

Pesticides Clopyralid

P018

0.1 µg/l

4

0

<0.011

<0.022

0

Pesticides Linuron

P051

0.1 µg/l

4

0

<0.007

<0.012

0

Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

P054

0.1 µg/l

4

0

<0.008

<0.012

0

Pesticides MCPP (Mecoprop)

P053

0.1 µg/l

4

0

<0.007

<0.009

0

Polycyclic Aromatic Hydrocarbons (Total by Calculation)

B011F

0.1 µg/l

4

0

0

0

0

Selenium (Total)

B009

10 µg Se/l

4

0

<0.32

<0.32

0

Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

D009B

10 µg/l

4

0

0

<0.4

0

Trihalomethanes (Total by Calculation)

D011

100 µg/l

4

0

31.51

48.9

0

Totals

140

0

Table 10: Quality of water at consumer’s tap (zones) – National Standards

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests Failed

1 percentile (representing a minimum)

99 percentile (representing a maximum)

No. of zones failing standard

Aluminium (Total)

A021

200 µg Al/l

4

0

<0.015

<14.5

0

Colour

A001

20 mg/l Pt/Co

4

0

<2.9

<2.9

0

Iron (Total)

A022

200 µg Fe/l

4

0

8.86

16.2

0

Manganese (Total)

A023

50 µg Mn/l

4

0

<0.85

<0.85

0

Odour

A003

0 Dilution number at 25°C

5

0

0

0

0

Sodium (Total)

A009

200 mg Na/l

4

0

18.8

39.5

0

Taste (Taste Quant)

A004

0 Dilution number at 25°C

4

0

0

0

0

Tetrachloromethane (Total)

D008

3 µg/l

4

0

<0.16

<0.16

0

Turbidity

A002

4 NTU

4

0

<0.13

0.18

0

Totals

37

0

Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

Parameter Name

Parameter Code

Prescribed Concentration or Value

Total Number of Tests

Tests exceeding specification

1 percentile (representing a minimum)

99 percentile (representing a maximum)

Ammonium (Total)

A014

0.5 mg NH4/l

4

0

<0.008

<0.008

Chloride

D002A

250 mg Cl/l

4

0

18.3

43.1

Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

C004A

0 number/100 ml

4

0

0

0

Coliform Bacteria (Indicator)

C001A

0 number/100 ml

12

0

0

0

Colony Counts After 3 Days At 22øc (Colony Counts)

C007

No abnormal change

4

N/A

0

1

Colony Counts After 48 Hours At 37øc (Colony Counts)

C013

No abnormal change

4

N/A

0

4

Conductivity (Electrical Conductivity)

D001

2500 µS/cm at 20°C

4

0

209

296

Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

A006

6.5 – 9.5 pH Value

4

0

7.51

7.87

Residual Disinfectant – Free

C009

No abnormal change

12

N/A

0.54

0.89

Residual Disinfectant – Total

C010

No abnormal change

12

N/A

0.61

0.92

Sulphate

A007

250 mg SO4/l

4

0

47.3

55.9

Total Organic Carbon

A017

No abnormal change

4

N/A

1.5

1.9

Totals

72

0

South East Water Limited – Boxley Treatment Works_Disinfection Risks

Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

Reference: SEW-2023-00006

Version Number: 2

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): South East Water Limited, with registered number 02679874 (hereinafter called ‘the Company’).

Assets Affected:

  • T371 – Boxley Treatment Works

Details of this Notice:

  1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a regulation 28(1) report of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated 21 September 2021, which states that there is or has been a significant risk of supplying water from Boxley Treatment Works (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
  2. Consequently, this Notice is served on the Company by the Inspectorate on behalf of the Secretary of State, under regulation 28(4) for the assets listed above, for risks associated with:

Description of Risk

Hazard/ Hazardous Event/ Parameter

Hazard I D

Inadequately disinfected water

Escherichia coli (E. coli)

T371-TREATMENT-C002

Inadequately disinfected water

Coliform bacteria

T371-TREATMENT-C001

Inadequately disinfected water

Enterococci

T3371-TREATMENT-C003

Table 1: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.
  1. The Company are required to satisfy the following requirements.

The date given is that until or by which the requirements must be maintained or satisfied, as appropriate.

Requirements:

(a) To maintain the following measures for the period specified in each case:

  1. Optimisation of all existing treatment processes.
    Date: Ongoing for the duration of this Notice
  2. Operation of all processes within defined normal operating ranges with appropriate triggers, responses and contingency procedures.
    Date: Ongoing for the duration of this Notice
  3. Online turbidity and chlorine monitoring with appropriate alarms and failsafe shutdown.
    Date: Ongoing for the duration of this Notice
  4. Enhanced and large volume operational monitoring for microbiological parameters at Boxley Treatment Works.
    Date: Ongoing for the duration of this Notice

(b) To review, revise or make operational the following measures, by the dates specified in each case:

  1. Review options to allow shutdown on final water turbidity and chlorine levels.
    Date: Complete
  2. Plan and design the option to allow shutdown on final water turbidity and chlorine levels.
    Date: 31 January 2025
  3. Install and commission the chosen solution to allow shutdown on final water turbidity and chlorine levels.
    Date: 30 September 2026

(c) To audit whether the measures have been effective by the following means:

  1. Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
    Date: Complete
  2. Implement, and keep under continuous review, the audit strategy defined in measure (c)1.
    Date: Following completion of measure (c)1 onwards.

(d) Not to supply water for regulation 4(1) purposes from Boxley Treatment Works, or not to so supply unless the specified conditions below are satisfied:

  1. Not applicable.

(e) To provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risks:

  1. Provide a progress report annually.
    Date: by 31 January each year.
  2. Provide a copy of the audit strategy.
    Date: Complete
  3. Report on the review of options to allow shutdown on final water turbidity and chlorine levels and provide dates for the planning, design, installation and commissioning.
    Date: Complete
  4. Confirm the completion of installation and commissioning of the shutdown processes.
    Date: 31 October 2026
  5. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  6. Submit a report in the event that any completed measures of this Notice need to be altered in any way, for any reason.
    Date: Ongoing for the duration of this Notice
  7. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 November 2027

Further Details of this Notice:

  1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
  2. Under regulation 28(6) the Inspectorate, on behalf of the Secretary of State, may by notice served on the Company, revoke or vary this Notice.
  3. Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991 (as amended).

Signed

Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
17 June 2024
Reference: SEW-2023-00006

Dŵr Cymru Welsh Water

Water supply arrangements

Company Assets

Number of treatment works

92

Number of service reservoirs 

157

Number of water supply zones

89

Length of mains pipe (km)

16,800km

Population Served

Population Supplied

3,797,000

Number of local authorities

41

Water Supplied

Water Supplied (l/day)

950,608,000

Percentage from surface sources

40%

Percentage of ground sources

55%

Percentage from mixed sources

5%

Area of supply

Blaenau Gwent, Bridgend, Caerphilly, Cardiff, Carmarthenshire, Ceredigion, Conwy, Denbighshire, Flintshire, Gwynedd, Herefordshire, County of, Isle of Anglesey, Merthyr Tydfil, Monmouthshire, Neath Port Talbot, Newport, Pembrokeshire, Powys, Rhondda Cynon Taf, Swansea, Torfaen, Vale of Glamorgan

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

961

0.25

2020

897

0.24

2021

900

0.24

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

3,066

0.81

2020

3,319

0.88

2021

3,036

0.80

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

A total of 3 consumers of Dŵr Cymru Welsh Water Services Ltd directly contacted DWI in 2021.


What is Regulation 31?

Regulation 31 of The Water Supply (Water Quality) Regulations 2016 (as amended)1 implements Article 10 of the Council of the European Union Drinking Water Directive (DWD) in England and Wales for all chemicals and construction products used by water undertakers, from the source of the water, up to the point of delivery to the consumer’s building. It sets out how approvals can be given to such construction products and materials that do not prejudice water quality and consumer safety.

Does your product require approval?

Learn more about Reg 31 and find out if your product requires approval

More
  1. Advice Sheets

    For all advice on the approval process and application requirements

Reg31 Enquiries

To contact the Regulation 31 team, please email reg31.enquiries@defra.gov.uk, or telephone +44(0)330 041 6501

Dŵr Cymru Welsh Water (England) 

Water supply arrangements

Company Assets

Number of treatment works

92

Number of service reservoirs 

157

Number of water supply zones

89

Length of mains pipe (km)

16,800km

Population Served

Population Supplied

3,797,000

Number of local authorities

41

Water Supplied

Water Supplied (l/day)

950,608,000

Percentage from surface sources

40%

Percentage of ground sources

55%

Percentage from mixed sources

5%

Area of supply

Worcestershire

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

961

0.25

2020

897

0.24

2021

900

0.24

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

3,066

0.81

2020

3,319

0.88

2021

3,036

0.80

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

No consumers of Dŵr Cymru Welsh Water Services Ltd directly contacted DWI in 2021. 

Water supply arrangements

Company Assets

Number of treatment works

92

Number of service reservoirs 

157

Number of water supply zones

89

Length of mains pipe (km)

16,800km

Population Served

Population Supplied

3,797,000

Number of local authorities

41

Water Supplied

Water Supplied (l/day)

950,608,000

Percentage from surface sources

40%

Percentage of ground sources

55%

Percentage from mixed sources

5%

Area of supply

Flintshire, Denbighshire, Powys, Gwynedd and Wrexham

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

961

0.25

2020

897

0.24

2021

900

0.24

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

3,066

0.81

2020

3,319

0.88

2021

3,036

0.80

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

No consumers of Hafren Dyfrdwy directly contacted DWI in 2021.

Water supply arrangements

Company Assets

Number of treatment works

92

Number of service reservoirs 

157

Number of water supply zones

89

Length of mains pipe (km)

16,800km

Population Served

Population Supplied

3,797,000

Number of local authorities

41

Water Supplied

Water Supplied (l/day)

950,608,000

Percentage from surface sources

40%

Percentage of ground sources

55%

Percentage from mixed sources

5%

Area of supply

North Norfolk, Hailsham, East Sussex, Surrey, Kent, Isle of Wight 

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

961

0.25

2020

897

0.24

2021

900

0.24

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

3,066

0.81

2020

3,319

0.88

2021

3,036

0.80

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

No consumers of Icosa Water directly contacted DWI in 2021.

Water supply arrangements

Company Assets

Number of treatment works

92

Number of service reservoirs 

157

Number of water supply zones

89

Length of mains pipe (km)

16,800km

Population Served

Population Supplied

3,797,000

Number of local authorities

41

Water Supplied

Water Supplied (l/day)

950,608,000

Percentage from surface sources

40%

Percentage of ground sources

55%

Percentage from mixed sources

5%

Area of supply

Flintshire 

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

961

0.25

2020

897

0.24

2021

900

0.24

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

3,066

0.81

2020

3,319

0.88

2021

3,036

0.80

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

No consumers of Albion Eco directly contacted DWI in 2021.

Independent Water Networks Ltd

Water supply arrangements

Company Assets

Number of treatment works

92

Number of service reservoirs 

157

Number of water supply zones

89

Length of mains pipe (km)

16,800km

Population Served

Population Supplied

3,797,000

Number of local authorities

41

Water Supplied

Water Supplied (l/day)

950,608,000

Percentage from surface sources

40%

Percentage of ground sources

55%

Percentage from mixed sources

5%

Area of supply

Barnet, Brent, Buckinghamshire, Central, Bedfordshire, Ealing, Essex, Harrow, Hertfordshire, Hillingdon, Kent, Luton, Buckinghamshire, Central Bedfordshire, East Riding of Yorkshire, Essex, Hertfordshire, Kent, Leeds, Milton Keynes, Newcastle upon Tyne, Northamptonshire, Tower Hamlets, Warwickshire, West Sussex 

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

961

0.25

2020

897

0.24

2021

900

0.24

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

3,066

0.81

2020

3,319

0.88

2021

3,036

0.80

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

No consumers of Independent Water Networks Ltd directly contacted DWI in 2021.

Water supply arrangements

Company Assets

Number of treatment works

92

Number of service reservoirs 

157

Number of water supply zones

89

Length of mains pipe (km)

16,800km

Population Served

Population Supplied

3,797,000

Number of local authorities

41

Water Supplied

Water Supplied (l/day)

950,608,000

Percentage from surface sources

40%

Percentage of ground sources

55%

Percentage from mixed sources

5%

Area of supply

Isles of Scilly

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

961

0.25

2020

897

0.24

2021

900

0.24

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

3,066

0.81

2020

3,319

0.88

2021

3,036

0.80

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

No consumers of Isles of Scilly directly contacted DWI in 2021.

On Tap – DWI podcasts

Lead

Chlorine

Water supply arrangements

Company Assets

Number of treatment works

92

Number of service reservoirs 

157

Number of water supply zones

89

Length of mains pipe (km)

16,800km

Population Served

Population Supplied

3,797,000

Number of local authorities

41

Water Supplied

Water Supplied (l/day)

950,608,000

Percentage from surface sources

40%

Percentage of ground sources

55%

Percentage from mixed sources

5%

Area of supply

Wiltshire, Buckinghamshire, Hampshire, Norfolk, Oxfordshire, Reading, Salford, Gloucestershire, Surrey, Sussex, Wiltshire, 9 London Borough 

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

961

0.25

2020

897

0.24

2021

900

0.24

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

3,066

0.81

2020

3,319

0.88

2021

3,036

0.80

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

No consumers of Leep Networks Water directly contacted DWI in 2021.

Water Companies

The Drinking Water Inspectorate works with a number of organisations concerned with the provision of drinking water.

This section provides information mainly of interest to water companies and new entrants to the water industry, local authorities and other regulators.

If you are unable to find what you are looking for please contact us on dwi.enquiries@defra.gov.uk.

Private Water Supplies

Leep Networks Water (Wales)

Water supply arrangements

Company Assets

Number of treatment works

92

Number of service reservoirs 

157

Number of water supply zones

89

Length of mains pipe (km)

16,800km

Population Served

Population Supplied

3,797,000

Number of local authorities

41

Water Supplied

Water Supplied (l/day)

950,608,000

Percentage from surface sources

40%

Percentage of ground sources

55%

Percentage from mixed sources

5%

Area of supply

Rhondda Cynon Taf 

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

961

0.25

2020

897

0.24

2021

900

0.24

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

3,066

0.81

2020

3,319

0.88

2021

3,036

0.80

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

No consumers of Leep Network Water (Wales) directly contacted the DWI in 2021.

Research

Welcome to the DWI Research pages. We believe that good quality science is crucial in the provision of credible and authoritative information on the health aspects of drinking water quality and it helps ensure that standards and regulations are adequate to protect public health. The DWI spends around £550K annually on research and development on drinking water quality issues.

These research web pages provides information to the aims and objectives of our research programme, access to the results and publications, and details of future research competitions. Summaries of our research output can also be found in the Chief Inspector’s report.

Enquiries about the DWI research programme, including publications of past research, should be directed to DWI Enquiries.

Press & Media

If you are seeking independent comment on drinking water quality for public supplies in England and Wales, please check if the subject is covered in our “DWI Press releases“. If your area of interest is not covered, please contact the following:

dwi.enquiries@defra.gov.uk

Or for a press officer:

In normal working hours
0330 041 6501

Out of hours
Please contact the Defra helpline on the following numbers and ask for the duty press officer

From within the UK: 0845 051 8486
From outside of the UK: +44 (0) 20 7238 6951

DWI press releases

Prosecution and Caution Record

Northumbrian, Essex and Suffolk Water

Water supply arrangements

Company Assets

Number of treatment works

92

Number of service reservoirs 

157

Number of water supply zones

89

Length of mains pipe (km)

16,800km

Population Served

Population Supplied

3,797,000

Number of local authorities

41

Water Supplied

Water Supplied (l/day)

950,608,000

Percentage from surface sources

40%

Percentage of ground sources

55%

Percentage from mixed sources

5%

Area of supply

Barking and Dagenham, County Durham, Darlington, Essex, Gateshead, Havering, Middlesbrough, Newcastle upon Tyne, Norfolk, North Tyneside, North Yorkshire, Northumberland, Redbridge, Redcar and Cleveland, South Tyneside, Southend-on-Sea, Stockton-on-Tees, Suffolk, Sunderland, Thurrock 

Consumer Contacts

Informing Consumers

Company Figure

Total Number

Rate per 1,000 population

2019

961

0.25

2020

897

0.24

2021

900

0.24

Industry Average

2021

9,913.96

1.22

Acceptability of water to consumers

Company Figure

Total Number

Rate per 1,000 population

2019

3,066

0.81

2020

3,319

0.88

2021

3,036

0.80

Industry Average

2021

2,832.12

1.08

Complaints to the Drinking Water Inspectorate

A total of 2 consumers of Northumbrian, Essex and Suffolk Water directly contacted DWI in 2021.

What we do

The Drinking Water Inspectorate (DWI) was formed in 1990 to provide independent reassurance that public water supplies in England and Wales are safe and drinking water quality is acceptable to consumers. We are a small organisation of 55 staff.

The main Drinking Water Inspectorate activities are as follows:

  • Technical audit of water companies covering the operating practices of water companies;
  • Assessment of water company sampling programmes and results;
  • Assessment of incidents potentially affecting drinking water quality or sufficiency;
  • Handling enquiries from the public;
  • Investigation of consumer complaints about drinking water quality;
  • Agreeing and managing water company programmes for improving drinking water quality including the Inspectorate’s input into Ofwat periodic review of water prices;
  • Enforcement activities;
  • Management of the Inspectorate’s scientific evidence and Defra’s water quality and health research programme;
  • Management of Product approvals;
  • Management of industry data;
  • Oversight of Local Authority enforcement of regulations for Private water supplies.

    What’s new

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    Water supply arrangements

    Company Assets

    Number of treatment works

    92

    Number of service reservoirs 

    157

    Number of water supply zones

    89

    Length of mains pipe (km)

    16,800km

    Population Served

    Population Supplied

    3,797,000

    Number of local authorities

    41

    Water Supplied

    Water Supplied (l/day)

    950,608,000

    Percentage from surface sources

    40%

    Percentage of ground sources

    55%

    Percentage from mixed sources

    5%

    Area of supply

    Hampshire, West Sussex, Portsmouth

    Consumer Contacts

    Informing Consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    961

    0.25

    2020

    897

    0.24

    2021

    900

    0.24

    Industry Average

    2021

    9,913.96

    1.22

    Acceptability of water to consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    3,066

    0.81

    2020

    3,319

    0.88

    2021

    3,036

    0.80

    Industry Average

    2021

    2,832.12

    1.08

    Complaints to the Drinking Water Inspectorate

    No consumers of Portsmouth Water Ltd directly contacted DWI in 2021. 

    Domestic drinking water pipes which are made of plastic can become contaminated when oil, fuel or other hydrocarbons come into contact with them in the ground. If you notice a fuel or petrol type taste or odour to your drinking water, contact your water company immediately as these can be dangerous to your health.

    Where could the contamination come from

    There are numerous sources of hydrocarbons around a domestic property. Some houses use oil for heating and have storage tanks. If you notice the level in the tank drops more than you would expect it to, based on your usage, this could indicate a leak. Containers such as jerry cans or paint pots can be knocked over or be spilt through careless use. A stationary vehicle for a long period might have an oil or petrol leak which could go unnoticed until it is moved. Renovation and DIY works could involve a wide range of solvents or hydrocarbons that could be spilt accidentally or disposed of incorrectly.

    How do I know when the problem started?

    It may take a long time for any of contamination to reach the water pipe which means the problem and its source may not be immediately obvious. There is also the chance that the contamination could be coming from further upstream via a long supply pipe, or even from the water main along the road.

    What should I do if I suspect or know of a leak or spill of oil or fuel?

    If you become aware of a fuel or other chemical spill or leak on your property or suspect that one may have occurred in the past, you should notify the environmental health team at your local council. The ground where the spill has occurred will likely be dug up and replaced with fresh soil. The sooner this is done the less chance the spill will have to spread further. Where a pipe has been contaminated it must be replaced as flushing will not resolve the problem. If the spill is at risk of contaminating a stream or other watercourse, then the Environment Agency emergency hotline should be contacted.

    What can be done to prevent contamination?

    Some specialist plastic pipes contain a barrier material, such as copper or foil, which will prevent chemicals leaching through pipes, however these are not used as standard. Storing chemical containers in suitable areas with adequate bunding and disposing of any chemicals no longer needed through the correct disposal methods is important. Where deliveries are made, great care should be taken during this time to prevent any spillage. Any storage structures should be serviced at regular intervals to monitor changes.

    ANH (Anglian Water Services Ltd)

    Report Data Range: For the whole year 2021

    Table 1: Quality of water leaving service treatment works – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    Nitrite (Total)

    A013B

    0.1 mg NO2/l

    4,317

    0

    <0.03

    <0.03

    0

    Totals

    4,317

    0

    Table 2: Quality of water leaving service treatment works – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    21,200

    1

    0

    0

    1

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    21,200

    8

    0

    0

    7

    Totals

    42,400

    9

    Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    21,215

    N/A

    0

    2

    Residual Disinfectant – Free

    C009

    No abnormal change

    21,411

    N/A

    <0.05

    1.28

    Residual Disinfectant – Total

    C010

    No abnormal change

    21,411

    N/A

    0.35

    1.5788

    Turbidity – Indicator

    A002A

    1 NTU

    21,211

    1

    <0.09

    0.24

    Totals

    85,248

    1

    Table 4: Quality of water leaving service reservoirs – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of reservoirs failing standard

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    16,265

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    16,265

    11

    0

    0

    0

    Totals:

    32,530

    11

    Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    16,290

    N/A

    0

    32

    Residual Disinfectant – Free

    C009

    No abnormal change

    16,290

    N/A

    0

    32

    Residual Disinfectant – Total

    C010

    No abnormal change

    16,295

    N/A

    0.12

    1.03

    Totals:

    48,880

    0

    Table 6: Quality of water leaving bulk supply points – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply point with failures

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    1,162

    0

    <0.079

    <0.433

    0

    Benzene (Total)

    F002

    1 µg/l

    1,164

    0

    <0.041

    <0.183

    0

    Boron

    D005A

    1 mg B/l

    1,152

    0

    <0.04332

    0.18

    0

    Bromate

    F003

    10 µg BrO3/l

    1,154

    0

    <0.35

    2.7305

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    605

    0

    <3.333

    <3.333

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    519

    0

    <0.097

    <0.097

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    1,044

    0

    0

    0.083

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    157

    0

    <0.01

    <0.01

    0

    Pesticides Aldrin

    P002

    0.03 µg/l

    52

    0

    <0.003

    <0.003

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    259

    0

    <0.004

    0.018

    0

    Pesticides Azoxystrobin

    P227

    0.1 µg/l

    53

    0

    <0.002

    0.003

    0

    Pesticides Benazolin (Total)

    P138

    0.1 µg/l

    60

    0

    <0.01

    <0.01

    0

    Pesticides Bentazone

    P006

    0.1 µg/l

    668

    0

    <0.008

    <0.008

    0

    Pesticides Boscalid

    P231

    0.1 µg/l

    16

    0

    <0.003

    0.004

    0

    Pesticides Bromacil

    P086

    0.1 µg/l

    106

    0

    <0.006

    <0.006

    0

    Pesticides Bromoxynil

    P008

    0.1 µg/l

    9

    0

    <0.01

    <0.01

    0

    Pesticides Carbetamide 

    P010

    0.1 µg/l

    229

    0

    <0.014

    <0.014

    0

    Pesticides Chloridazon

    P162

    0.1 µg/l

    101

    0

    <0.012

    <0.012

    0

    Pesticides Chlormequat

    P163

    0.1 µg/l

    4

    0

    <0.005

    <0.005

    0

    Pesticides Chlortoluron

    P014

    0.1 µg/l

    59

    0

    <0.01

    <0.01

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    437

    0

    <0.018

    0.03148

    0

    Pesticides Cyanazine

    P092

    0.1 µg/l

    9

    0

    <0.008

    <0.008

    0

    Pesticides Cyproconazole

    P207

    0.1 µg/l

    15

    0

    <0.003

    <0.003

    0

    Pesticides Dicamba

    P025

    0.1 µg/l

    8

    0

    <0.017

    <0.017

    0

    Pesticides Dichlorprop

    P026

    0.1 µg/l

    17

    0

    <0.004

    0.005

    0

    Pesticides Dieldrin

    P028

    0.03 µg/l

    51

    0

    <0.003

    <0.003

    0

    Pesticides Diuron

    P032

    0.1 µg/l

    73

    0

    <0.013

    <0.013

    0

    Pesticides Ethofumersate

    P221

    0.1 µg/l

    586

    0

    <0.006

    <0.006

    0

    Pesticides Fenpropidin

    P168

    0.1 µg/l

    9

    0

    <0.011

    <0.012

    0

    Pesticides Flufenacet

    P230

    0.1 µg/l

    163

    0

    <0.003

    0.02236

    0

    Pesticides Fluroxypyr

    P040

    0.1 µg/l

    325

    0

    <0.02

    <0.02

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    347

    0

    <0.007

    0.01504

    0

    Pesticides Heptachlor

    P043

    0.03 µg/l

    52

    0

    <0.002

    <0.002

    0

    Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

    P044

    0.03 µg/l

    52

    0

    <0.003

    <0.003

    0

    Pesticides Isoproturon

    P048

    0.1 µg/l

    125

    0

    <0.006

    <0.006

    0

    Pesticides Lenacil

    P109

    0.1 µg/l

    71

    0

    <0.002

    0.065

    0

    Pesticides Malathion

    P052

    0.1 µg/l

    9

    0

    <0.007

    0.077

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    138

    0

    <0.008

    <0.008

    0

    Pesticides MCPB

    P055

    0.1 µg/l

    16

    0

    <0.006

    <0.006

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    237

    0

    <0.006

    0.02126

    0

    Pesticides Metalaxyl

    P209

    0.1 µg/l

    9

    0

    <0.01

    <0.012

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    573

    0

    <0.008

    0.04726

    0

    Pesticides Metamitron

    P194

    0.1 µg/l

    43

    0

    <0.017

    <0.017

    0

    Pesticides Metazachlor

    P203

    0.1 µg/l 

    104

    0

    <0.002

    <0.03

    0

    Pesticides Metribuzin

    P152

    0.1 µg/l

    9

    0

    <0.008

    <0.008

    0

    Pesticides Monuron

    P113

    0.1 µg/l

    32

    0

    <0.012

    <0.012

    0

    Pesticides Pentachlorophenol

    P060

    0.1 µg/l

    6

    0

    0.006

    <0.007

    0

    Pesticides Pirimicarb

    P064

    0.1 µg/l

    10

    0

    <0.007

    <0.008

    0

    Pesticides Propamocarb

    P238

    0.1 µg/l

    8

    0

    <0.001

    <0.001

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    341

    0

    <0.004

    0.03964

    0

    Pesticides Prosulfocarb

    P243

    0.1 µg/l

    158

    0

    <0.00359

    0.005

    0

    Pesticides Quinmerac

    P224

    0.1 µg/l

    274

    0

    <0.013

    0.015

    Pesticides Simazine

    P073

    0.1 µg/l

    308

    0

    <0.01

    0.01491

    0

    Pesticides Tebuconazole

    P177

    0.1 µg/l

    26

    0

    <0.004

    <0.004

    0

    Pesticides Terbutryn

    P077

    0.1 µg/l

    43

    0

    <0.01

    <0.01

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    31

    0

    <0.012

    <0.012

    0

    Pesticides Trietazine

    P132

    0.1 µg/l

    42

    0

    <0.016

    <0.016

    0

    Radon

    F031

    100 Bq/l

    8

    0

    <1

    1.2

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    1,198

    0

    0

    1.6618

    0

    Totals

    14,531

    0

    Table 7: Quality of water leaving bulk supply points – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply points with failures

    Tetrachloromethane (Total)

    D008

    3 µg/l

    1,157

    0

    <0.081

    0.33186

    0

    Totals

    1,157

    0

    Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Chloride

    D002A

    250 mg Cl/l

    1,153

    0

    13.754

    132

    Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    1,152

    0

    0

    0

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    5,119

    0

    321.6

    1006.8

    Gross Alpha

    F004

    0.1 Bq/l

    22

    1

    <0.02

    0.236

    Gross Beta

    F005

    1 Bq/l

    22

    0

    <0.054

    0.197

    Sulphate

    A007

    250 mg SO4/l

    1,152

    0

    <14.5

    172

    Total Organic Carbon

    A017

    No abnormal change

    1,153

    N/A

    0.6708

    3.9014

    Tritium

    F006

    100 Bq/l

    16

    0

    5.79

    <6

    Totals

    9,789

    1

    Table 9: Quality of water at consumer’s tap (zones) – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of zones failing standard

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    51

    0

    <0.79

    <0.433

    0

    Antimony

    B008A

    5 µg Sb/l

    1,340

    0

    <0.086

    0.49

    0

    Arsenic (Total)

    B001A

    10 µg As/l

    1,340

    0

    <0.157

    3.3959

    0

    Benzene (Total)

    F002

    1 µg/l

    50

    0

    <0.041

    <0.183

    0

    Benzo[a]Pyrene (Total)

    D007

    0.01 µg/l

    1,336

    0

    <0.002

    <0.002

    0

    Boron

    D005A

    1 mg B/l

    51

    0

    <0.04332

    0.451

    0

    Bromate

    F003

    10 µg BrO3/l

    148

    0

    <0.35

    3.168

    0

    Cadmium (Total)

    B002

    5 µg Cd/l

    1,340

    0

    <0.025

    <0.063

    0

    Chromium (Total)

    B004

    50 µg Cr/l

    1,343

    0

    <0.293

    1.056

    0

    Copper (Total)

    A024A

    2 mg Cu/l

    1,339

    0

    0.00394

    0.7494

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    51

    0

    <3.333

    <3.333

    0

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    13,123

    4

    0

    0

    4

    Enterococci (Confirmed)

    C003

    0 number/100 ml

    1,341

    0

    0

    0

    0

    Fluoride (Fluoridated)

    A027A

    1.2 mg F/l

    222

    106

    0.10692

    1.08185

    26

    Fluoride (Total)

    A027

    1.5 mg F/l

    1,340

    0

    0.09541

    1.29177

    0

    Lead (10 – will apply 25.12.2013)

    B007B

    10 µg Pb/l

    1,340

    2

    <0.133

    7.0159

    2

    Mercury (Total)

    B005

    1 µg Hg/l 

    51

    0

    <0.097

    <0.097

    0

    Nickel (Total) 

    B006A 

    20 µg Ni/l

    1,339

    8

    <0.613

    14.36

    7

    Nitrate (Total)

    A012

    50 mg NO3/l

    2,893

    0

    <7.526

    42

    0

    Nitrite – Consumer’s Taps

    A013A

    0.5 mg NO2/l

    2,893

    0

    <0.03

    0.255

    0

    Nitrite/Nitrate formula

    A013C

    1 mg/l

    2,893

    0

    0

    0.84212

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    47

    0

    0

    0.07

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    1

    0

    <0.01

    <0.01

    0

    Pesticides 2 4-DB

    P082

    0.1 µg/l

    1

    0

    <0.008

    <0.008

    0

    Pesticides Aldrin

    P002

    0.03 µg/l

    30

    0

    <0.003

    <0.003

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    13

    0

    <0.004

    0.023

    0

    Pesticides Benazolin (Total)

    P138

    0.1 µg/l

    1

    0

    <0.01

    <0.01

    0

    Pesticides Bentazone

    P006

    0.1 µg/l

    5

    0

    <0.008

    <0.008

    0

    Pesticides Bromacil

    P086

    0.1 µg/l

    4

    0

    <0.006

    <0.006

    0

    Pesticides Carbetamide 

    P010

    0.1 µg/l

    7

    0

    <0.014

    <0.014

    0

    Pesticides Chlorfenvinphos

    P013

    0.1 µg/l

    1

    0

    <0.007

    <0.007

    0

    Pesticides Chloridazon

    P162

    0.1 µg/l

    1

    0

    <0.012

    <0.012

    0

    Pesticides Chlormequat

    P163

    0.1 µg/l

    1

    0

    <0.005

    <0.005

    0

    Pesticides Chlorothalonil

    P015

    0.1 µg/l

    1

    0

    <0.01

    <0.01

    0

    Pesticides Chlortoluron

    P014

    0.1 µg/l

    1

    0

    <0.01

    <0.01

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    17

    0

    <0.018

    0.022

    0

    Pesticides Cyanazine

    P092

    0.1 µg/l

    1

    0

    <0.008

    <0.008

    0

    Pesticides Dichlorprop

    P026

    0.1 µg/l

    1

    0

    <0.004

    <0.004

    0

    Pesticides Dieldrin

    P028

    0.03 µg/l

    30

    0

    <0.003

    <0.003

    0

    Pesticides Fluroxypyr

    P040

    0.1 µg/l

    1

    0

    <0.02

    <0.02

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    1

    0

    <0.007

    <0.007

    0

    Pesticides Heptachlor

    P043

    0.03 µg/l

    30

    0

    <0.002

    <0.002

    0

    Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

    P044

    0.03 µg/l

    30

    0

    <0.003

    <0.003

    0

    Pesticides Isoproturon

    P048

    0.1 µg/l

    5

    0

    <0.006

    <0.006

    0

    Pesticides Linuron

    P051

    0.1 µg/l

    28

    0

    <0.014

    <0.014

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    1

    0

    <0.008

    <0.008

    0

    Pesticides MCPB

    P055

    0.1 µg/l

    1

    0

    <0.006

    <0.006

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    5

    0

    <0.006

    <0.006

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    18

    0

    <0.008

    0.056

    0

    Pesticides Metamitron

    P194

    0.1 µg/l

    1

    0

    <0.017

    <0.017

    0

    Pesticides Metazachlor

    P203

    0.1 µg/l 

    1

    0

    <0.03

    <0.03

    0

    Pesticides Monuron

    P113

    0.1 µg/l

    28

    0

    <0.012

    <0.012

    0

    Pesticides Pirimicarb

    P064

    0.1 µg/l

    1

    0

    <0.007

    <0.007

    0

    Pesticides Prometryne

    P070

    0.1 µg/l

    1

    0

    <0.01

    <0.01

    0

    Pesticides Propazine

    P066

    0.1 µg/l

    1

    0

    <0.01

    <0.01

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    7

    0

    <0.004

    0.04

    0

    Pesticides Quinmerac

    P244

    0.1 µg/l

    1

    0

    <0.013

    <0.013

    0

    Pesticides Simazine

    P073

    0.1 µg/l

    7

    0

    <0.01

    <0.01

    0

    Pesticides Terbutryn

    P077

    0.1 µg/l

    1

    0

    <0.01

    <0.01

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    1

    0

    <0.012

    <0.012

    0

    Pesticides Trietazine

    P132

    0.1 µg/l

    28

    0

    <0.016

    <0.016

    0

    Polycyclic Aromatic Hydrocarbons (Total by Calculation)

    B011F

    0.1 µg/l

    1,337

    0

    0

    0

    0

    Selenium (Total)

    B009

    10 µg Se/l

    1,340

    0

    <0.722

    3.5759

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    32

    0

    0

    0

    0

    Trihalomethanes (Total by Calculation)

    D011

    100 µg/l

    1,358

    0

    0

    51.941

    0

    Totals

    40,252

    120

    Table 10: Quality of water at consumer’s tap (zones) – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    No. of zones failing standard

    Aluminium (Total)

    A021

    200 µg Al/l

    4,383

    0

    <6

    34.028

    0

    Colour

    A001

    20 mg/l Pt/Co

    4,917

    0

    <0.68

    2.3

    0

    Iron (Total)

    A022

    200 µg Fe/l

    4,383

    6

    <7

    78.16

    6

    Manganese (Total)

    A023

    50 µg Mn/l

    4,383

    0

    <3

    3.716

    0

    Odour

    A003

    0 Dilution number at 25°C

    4,920

    41

    0

    0

    32

    Sodium (Total)

    A009

    200 mg Na/l

    1,340

    0

    9.4505

    81.272

    0

    Taste (Taste Quant)

    A004

    0 Dilution number at 25°C

    4,917

    16

    0

    0

    17

    Tetrachloromethane (Total)

    D008

    3 µg/l

    51

    0

    <0.081

    <0.313

    0

    Turbidity

    A002

    4 NTU

    4,917

    0

    <0.09

    <0.313

    0

    Totals

    34,211

    63

    Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Ammonium (Total)

    A014

    0.5 mg NH4/l

    2,894

    0

    <0.14

    0.26205

    Chloride

    D002A

    250 mg Cl/l

    51

    0

    <6.83

    82

    Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    51

    0

    0

    0

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    13,123

    29

    0

    0

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    4,916

    N/A

    0

    22

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    1,912

    0

    283.39

    747.87

    Gross Alpha

    F004

    0.1 Bq/l

    8

    0

    <0.02

    0.088

    Gross Beta

    F005

    1 Bq/l

    8

    0

    0.005

    0.256

    Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

    A006

    6.5 – 9.5 pH Value

    4,917

    0

    7.08

    7.87

    Residual Disinfectant – Free

    C009

    No abnormal change

    13,246

    N/A

    <0.05

    0.73

    Residual Disinfectant – Total

    C010

    No abnormal change

    13,245

    N/A

    0.11

    1.13

    Sulphate

    A007

    250 mg SO4/l

    51

    0

    <14.5

    124

    Total Organic Carbon

    A017

    No abnormal change

    9

    0

    <6

    6.3

    Tritium

    F006

    100 Bq/l

    9

    0

    <6

    6.3

    Totals

    54,482

    29

    LNW (Leep Networks Water)

    Report Data Range: For the whole year 2021

    Table 9: Quality of water at consumer’s tap (zones) – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of zones failing standard

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    117

    0

    <0.16

    <0.16

    0

    Antimony

    B008A

    5 µg Sb/l

    117

    0

    0.0536

    0.4864

    0

    Arsenic (Total)

    B001A

    10 µg As/l

    117

    0

    0.1418

    1.3564

    0

    Benzene (Total)

    F002

    1 µg/l

    117

    0

    <0.06

    <0.06

    0

    Benzo[a]Pyrene (Total)

    D007

    0.01 µg/l

    117

    0

    <0.00057

    <0.00285

    0

    Boron

    D005A

    1 mg B/l

    117

    0

    <0.0319

    <0.081938

    0

    Bromate

    F003

    10 µg BrO3/l

    117

    0

    <0.15

    4.24

    0

    Cadmium (Total)

    B002

    5 µg Cd/l

    117

    0

    <0.01

    <0.03

    0

    Chromium (Total)

    B004

    50 µg Cr/l

    117

    0

    0.0418

    5.7286

    0

    Copper (Total)

    A024A

    2 mg Cu/l

    117

    0

    0.00035

    0.59638

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    117

    0

    <5.5

    19.28

    0

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    348

    0

    0

    0

    0

    Enterococci (Confirmed)

    C003

    0 number/100 ml

    116

    0

    0

    0

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    117

    0

    <0.04

    0.3064

    0

    Lead (10 – will apply 25.12.2013)

    B007B

    10 µg Pb/l

    117

    0

    <0.04

    4.6666

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    117

    0

    <0.06

    <0.06

    0

    Nickel (Total) 

    B006A 

    20 µg Ni/l

    117

    2

    <0.18

    141.06

    2

    Nitrate (Total)

    A012

    50 mg NO3/l

    117

    0

    <2.11

    41.552

    0

    Nitrite – Consumer’s Taps

    A013A

    0.5 mg NO2/l

    117

    0

    <0.002

    0.2008

    0

    Nitrite/Nitrate formula

    A013C

    1 mg/l

    117

    0

    0

    0.83892

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    75

    0

    0

    0.112

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    4

    0

    <0.012

    <0.012

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    17

    0

    <0.004

    0.023

    0

    Pesticides Bentazone

    P006

    0.1 µg/l

    4

    0

    <0.002

    <0.004

    0

    Pesticides Carbendazim (Total)

    P150

    0.1 µg/l

    4

    0

    <0.003

    <0.003

    0

    Pesticides Carbetamide

    P010

    0.1 µg/l

    4

    0

    <0.008

    <0.01

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    13

    0

    <0.011

    0.03

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    5

    0

    <0.005

    <0.005

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    4

    0

    <0.008

    <0.012

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    5

    0

    <0.007

    <0.009

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l

    68

    0

    <0.007

    0.041

    0

    Pesticides Picloram (Total)

    P122

    0.1 µg/l

    4

    0

    <0.013

    <0.019

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    12

    0

    <0.007

    <0.009

    0

    Pesticides Prosulfocarb

    P243

    0.1 µg/l

    4

    0

    <0.007

    <0.009

    0

    Pesticides Quinmerac

    P244

    0.1 µg/l

    4

    0

    <0.006

    <0.007

    0

    Polycyclic Aromatic Hydrocarbons (Total by Calculation)

    B011F

    0.1 µg/l

    117

    0

    0

    0.001784

    0

    Selenium (Total)

    B009

    10 µg Se/l

    117

    0

    0.1536

    4.6078

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    117

    0

    0

    1.8622

    0

    Trihalomethanes (Total by Calculation)

    D011

    100 µg/l

    117

    0

    0

    56.7778

    0

    Totals

    3,265

    2

    Table 10: Quality of water at consumer’s tap (zones) – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    No. of zones failing standard

    Aluminium (Total)

    A021

    200 µg Al/l

    117

    0

    <6.9

    41.538

    0

    Colour

    A001

    20 mg/l Pt/Co

    121

    0

    <2.9

    <3.78

    0

    Iron (Total)

    A022

    200 µg Fe/l

    117

    0

    <3.72

    43.28

    0

    Manganese (Total)

    A023

    50 µg Mn/l

    117

    0

    <0.3

    2.412

    0

    Odour

    A003

    0 Dilution number at 25°C

    120

    1

    0

    0.79

    1

    Sodium (Total)

    A009

    200 mg Na/l

    117

    0

    <0.77

    45.048

    0

    Taste (Taste Quant)

    A004

    0 Dilution number at 25°C

    120

    0

    0

    0

    0

    Tetrachloromethane (Total)

    D008

    3 µg/l

    117

    0

    <0.16

    <0.16

    0

    Turbidity

    A002

    4 NTU

    121

    0

    <0.13

    0.4856

    0

    Totals

    1,067

    1

    Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Ammonium (Total)

    A014

    0.5 mg NH4/l

    121

    0

    <0.008

    0.20878

    Chloride

    D002A

    250 mg Cl/l

    117

    0

    5.908

    63.698

    Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    116

    0

    0

    0

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    348

    0

    0

    0

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    120

    N/A

    0

    157

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    121

    0

    73.442

    756.12

    Gross Alpha

    F004

    0.1 Bq/l

    19

    0

    <0.012

    0.092

    Gross Beta

    F005

    1 Bq/l

    19

    0

    0.019

    0.189

    Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

    A006

    6.5 – 9.5 pH Value

    121

    0

    6.9664

    8.0112

    Residual Disinfectant – Total

    C010

    No abnormal change

    359

    N/A

    0.13

    0.984

    Sulphate

    A007

    250 mg SO4/l

    117

    0

    <0.54

    116.64

    Total Organic Carbon

    A017

    No abnormal change

    117

    N/A

    0.354

    3.6

    Tritium

    F006

    100 Bq/l

    15

    0

    <5.6

    5.69

    Totals

    1,710

    0

    Water supply arrangements

    Company Assets

    Number of treatment works

    92

    Number of service reservoirs 

    157

    Number of water supply zones

    89

    Length of mains pipe (km)

    16,800km

    Population Served

    Population Supplied

    3,797,000

    Number of local authorities

    41

    Water Supplied

    Water Supplied (l/day)

    950,608,000

    Percentage from surface sources

    40%

    Percentage of ground sources

    55%

    Percentage from mixed sources

    5%

    Area of supply

    Kent, Surrey, Sutton, West Sussex

    Consumer Contacts

    Informing Consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    961

    0.25

    2020

    897

    0.24

    2021

    900

    0.24

    Industry Average

    2021

    9,913.96

    1.22

    Acceptability of water to consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    3,066

    0.81

    2020

    3,319

    0.88

    2021

    3,036

    0.80

    Industry Average

    2021

    2,832.12

    1.08

    Complaints to the Drinking Water Inspectorate

    No consumers of SES Water directly contacted DWI in 2021.

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    Drinking Water Inspectorate

    The Drinking Water Inspectorate (DWI) was formed in 1990 to provide independent reassurance that water supplies in England and Wales are safe and drinking water quality is acceptable to consumers.

    Drinking Water 2023

    Safe, clean drinking water is vital to public health and the wellbeing of our society, now and into the future. This is the central tenet of the vision and strategy of the Drinking Water Inspectorate. Drinking Water 2023 published in July 2024.

    Triennial Reports 2017-2019

    Three yearly report for both England and Wales on the quality of drinking water to inform consumers

    05

    Regions in England and Wales

    25

    Water Companies

    Use our map to find your local water company

    Find contact details, report a problem, look at incidents in your area.

    See ongoing improvement in your area, how your water company is improving and find the water quality in your area.

    Find your local company

    Contact Us


    Water quality

    If you are concerned about the quality of your drinking water you should contact your water company in the first instance. A number for your water company can be found here.

     

    Learn more about your water


    The Drinking Water Inspectorate provides information and advice to consumers on the quality of drinking water.

    Advice for finding a plumber
    Algae in drinking water
    Animals in drinking water
    Bills and compensation
    Blue water/Copper in drinking water
    Boil water notice
    Bottled water
    Chlorine

    View all leaflets

    Water supply arrangements

    Company Assets

    Number of treatment works

    92

    Number of service reservoirs 

    157

    Number of water supply zones

    89

    Length of mains pipe (km)

    16,800km

    Population Served

    Population Supplied

    3,797,000

    Number of local authorities

    41

    Water Supplied

    Water Supplied (l/day)

    950,608,000

    Percentage from surface sources

    40%

    Percentage of ground sources

    55%

    Percentage from mixed sources

    5%

    Area of supply

    Bracknell Forest, East Sussex, Hampshire, Kent, Surrey, West Sussex, Windsor and Maidenhead, Wokingham

    Consumer Contacts

    Informing Consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    961

    0.25

    2020

    897

    0.24

    2021

    900

    0.24

    Industry Average

    2021

    9,913.96

    1.22

    Acceptability of water to consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    3,066

    0.81

    2020

    3,319

    0.88

    2021

    3,036

    0.80

    Industry Average

    2021

    2,832.12

    1.08

    Complaints to the Drinking Water Inspectorate

    A total of 2 consumers of South East Water directly contacted DWI in 2021.

    Southern Water Services Ltd 

    Water supply arrangements

    Company Assets

    Number of treatment works

    92

    Number of service reservoirs 

    157

    Number of water supply zones

    89

    Length of mains pipe (km)

    16,800km

    Population Served

    Population Supplied

    3,797,000

    Number of local authorities

    41

    Water Supplied

    Water Supplied (l/day)

    950,608,000

    Percentage from surface sources

    40%

    Percentage of ground sources

    55%

    Percentage from mixed sources

    5%

    Area of supply

    Brighton and Hove, East Sussex, Hampshire, Isle of Wight, Kent, Medway, Southampton, West Sussex

    Consumer Contacts

    Informing Consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    961

    0.25

    2020

    897

    0.24

    2021

    900

    0.24

    Industry Average

    2021

    9,913.96

    1.22

    Acceptability of water to consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    3,066

    0.81

    2020

    3,319

    0.88

    2021

    3,036

    0.80

    Industry Average

    2021

    2,832.12

    1.08

    Complaints to the Drinking Water Inspectorate

    No consumers of Southern Water Services Ltd directly contacted DWI in 2021. 

    Overview

    Despite its reputation as a rainy country, England is susceptible to periods of drought. Drought is a natural event which is often characterised by some degree of rainfall shortage over a period of time, resulting in a reduction of water supplies. In order to prepare and tackle periods of drought, certain restrictions on water usage may be implemented.

    Role of the DWI

    The DWI is not able to deal with matters regarding drought. The Environment Agency (EA) has a duty to manage water resources in England. All enquiries should be directed to the Environment Agency, contact details can be found on their website.

    Role of Environment Agency

    During periods of drought, The EA implement drought plans that set out their methods to routinely monitor, measure and report on the water situation across England. This information helps with the assessment of the national and local water situation including prospects of water shortages. Drought Plans are also produced by water companies, which are a legal obligation for them, more information on these can be found on their websites.

    Role of Water Companies

    During drought, water companies have the authority to restrict non-essential use of water, which is often too referred to as hose-pipe bans. These restrictions are covered by the Flood and Water Management Act 2010, Section 36. This also updates section 76 of the Water Industry Act 1991, the Water Use (Temporary Bans) Order 2010.

    Water companies may apply for a drought permit or drought order, these allow for water companies to implement restrictions on water demand, maintain public water supplies and to take water from new sources. More information can be found at the GOV.UK website in the Drought Order Direction 2011, which lists the restrictions on water under a drought order.

    South Staffordshire Water plc

    Water supply arrangements

    Company Assets

    Number of treatment works

    92

    Number of service reservoirs 

    157

    Number of water supply zones

    89

    Length of mains pipe (km)

    16,800km

    Population Served

    Population Supplied

    3,797,000

    Number of local authorities

    41

    Water Supplied

    Water Supplied (l/day)

    950,608,000

    Percentage from surface sources

    40%

    Percentage of ground sources

    55%

    Percentage from mixed sources

    5%

    Area of supply

    Staffordshire, Worcestershire, Shropshire, Derbyshire and Leicestershire, West Midlands

    Consumer Contacts

    Informing Consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    961

    0.25

    2020

    897

    0.24

    2021

    900

    0.24

    Industry Average

    2021

    9,913.96

    1.22

    Acceptability of water to consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    3,066

    0.81

    2020

    3,319

    0.88

    2021

    3,036

    0.80

    Industry Average

    2021

    2,832.12

    1.08

    Complaints to the Drinking Water Inspectorate

    A total of 1 consumer of South Staffordshire Water plc directly contacted DWI in 2021.

    NES (Northumbrian, Essex and Suffolk Water Ltd)

    Report Data Range: For the whole year 2021

    Table 1: Quality of water leaving service treatment works – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    Nitrite (Total)

    A013B

    0.1 mg NO2/l

    3,161

    0

    <0.0035

    <0.0058

    0

    Totals

    3,161

    0

    Table 2: Quality of water leaving service treatment works – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    9,928

    1

    0

    0

    1

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    9,928

    7

    0

    0

    6

    Totals

    19,856

    8

    Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    9,915

    N/A

    0

    4

    Residual Disinfectant – Free

    C009

    No abnormal change

    6,318

    N/A

    0.19

    1.17

    Residual Disinfectant – Total

    C010

    No abnormal change

    9,915

    N/A

    0.36

    1.3784

    Turbidity – Indicator

    A002A

    1 NTU

    9,928

    1

    <0.09

    0.26

    Totals

    36,076

    1

    Table 4: Quality of water leaving service reservoirs – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of reservoirs failing standard

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    15,350

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    15,350

    3

    0

    0

    1

    Totals:

    30,700

    3

    Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    15,322

    N/A

    0

    212

    Residual Disinfectant – Free

    C009

    No abnormal change

    10,026

    N/A

    <0.05

    0.93

    Residual Disinfectant – Total

    C010

    No abnormal change

    15,328

    N/A

    0.09

    1.05

    Totals:

    40,676

    0

    Table 6: Quality of water leaving bulk supply points – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply point with failures

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    346

    0

    <0.079

    <0.2

    0

    Benzene (Total)

    F002

    1 µg/l

    346

    0

    <0.03

    <0.041

    0

    Boron

    D005A

    1 mg B/l

    72

    0

    0.043

    0.072

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    346

    0

    <5.5

    <5.5

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    72

    0

    0.16

    0.35

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    346

    0

    <0.022

    <0.022

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    346

    0

    0

    0.14618

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    346

    0

    <0.0036

    0.006465

    0

    Pesticides 2 4-DB

    P082

    0.1 µg/l

    72

    0

    <0.012

    <0.012

    0

    Pesticides 2,4,5-T

    P076

    0.1 µg/l

    72

    0

    <0.0044

    <0.0044

    0

    Pesticides Aldrin

    P002

    0.03 µg/l

    343

    0

    <0.0025

    <0.0025

    0

    Pesticides Aminomethylphosphonic acid

    P273

    0.1 µg/l

    346

    0

    <0.0093

    <0.012

    0

    Pesticides Asulam

    P133

    0.1 µg/l

    344

    0

    <0.017

    <0.017

    0

    Pesticides Benazolin (Total)

    P138

    0.1 µg/l

    274

    0

    <0.013

    <0.013

    0

    Pesticides Bentazone

    P006

    0.1 µg/l

    346

    0

    <0.0025

    0.01153

    0

    Pesticides Carbetamide 

    P010

    0.1 µg/l

    346

    0

    <0.0083

    <0.0083

    0

    Pesticides Chloridazon

    P162

    0.1 µg/l

    72

    0

    <0.0048

    <0.0048

    0

    Pesticides Chlormequat

    P163

    0.1 µg/l

    274

    0

    <0.02

    <0.02

    0

    Pesticides Chlorothalonil

    P015

    0.1 µg/l

    72

    0

    <0.0071

    <0.0071

    0

    Pesticides Chlortoluron

    P014

    0.1 µg/l

    346

    0

    <0.0031

    <0.0031

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    345

    0

    <0.013

    0.03716

    0

    Pesticides Cypermethrin

    P094

    0.1 µg/l

    272

    0

    <0.012

    <0.016

    0

    Pesticides Diazinon

    P024

    0.1 µg/l

    273

    0

    <0.0074

    <0.0094

    0

    Pesticides Dicamba

    P025

    0.1 µg/l

    72

    0

    <0.017

    <0.017

    0

    Pesticides Dichlorprop

    P026

    0.1 µg/l

    72

    0

    <0.0041

    <0.0041

    0

    Pesticides Dieldrin

    P028

    0.03 µg/l

    343

    0

    <0.0019

    <0.0019

    0

    Pesticides Diflufenican

    P157

    0.1 µg/l

    345

    0

    <0.0072

    <0.0086

    0

    Pesticides Diuron

    P032

    0.1 µg/l

    346

    0

    <0.0055

    <0.0055

    0

    Pesticides Ethofumersate

    P221

    0.1 µg/l

    346

    0

    <0.007

    <0.007

    0

    Pesticides Fenpropimorph

    P037

    0.1 µg/l

    273

    0

    <0.0083

    <0.0089

    0

    Pesticides Flufenacet

    P230

    0.1 µg/l

    72

    0

    <0.0052

    0.053

    0

    Pesticides Fluroxypyr

    P040

    0.1 µg/l

    326

    0

    <0.018

    <0.018

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    346

    0

    <0.0077

    <0.0079

    0

    Pesticides Heptachlor

    P043

    0.03 µg/l

    343

    0

    <0.0026

    <0.0026

    0

    Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

    P044

    0.03 µg/l

    343

    0

    0

    0

    0

    Pesticides Hexachlorobenzene

    P045

    0.1 µg/l

    72

    0

    <0.0065

    <0.0065

    0

    Pesticides Isoproturon

    P048

    0.1 µg/l

    346

    0

    <0.0025

    0.0097

    0

    Pesticides Lenacil

    P109

    0.1 µg/l

    72

    0

    <0.0057

    <0.0057

    0

    Pesticides Linuron

    P051

    0.1 µg/l

    72

    0

    <0.0034

    <0.0034

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    346

    0

    <0.0019

    0.01665

    0

    Pesticides MCPB

    P055

    0.1 µg/l

    274

    0

    <0.014

    <0.014

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    346

    0

    <0.0041

    0.005359

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    346

    0

    <0.021

    0.05265

    0

    Pesticides Metamitron

    P194

    0.1 µg/l

    346

    0

    <0.0074

    <0.0074

    0

    Pesticides Metazachlor

    P203

    0.1 µg/l 

    345

    0

    <0.01

    0.01916

    0

    Pesticides Oxamyl

    P263

    0.1 µg/l

    72

    0

    <0.0023

    <0.023

    0

    Pesticides Pendimethalin

    P118

    0.1 µg/l

    345

    0

    <0.0064

    <0.0082

    0

    Pesticides Pentachlorophenol

    P060

    0.1 µg/l

    72

    0

    <0.0062

    <0.0062

    0

    Pesticides Picloram (Total)

    P122

    0.1 µg/l

    346

    0

    <0.012

    <0.012

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    345

    0

    <0.0072

    0.07356

    0

    Pesticides Quinmerac

    P224

    0.1 µg/l

    338

    0

    <0.0052

    0.02

    0

    Pesticides Tebuconazole

    P177

    0.1 µg/l

    77

    0

    <0.0039

    <0.0039

    0

    Pesticides Terbutryn

    P077

    0.1 µg/l

    72

    0

    <0.0047

    <0.0073

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    346

    0

    <0.012

    <0.012

    0

    Radon

    F031

    100 Bq/l

    25

    0

    <10

    31

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    346

    0

    0

    0

    0

    Totals

    14,208

    0

    Table 7: Quality of water leaving bulk supply points – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply points with failures

    Tetrachloromethane (Total)

    D008

    3 µg/l

    346

    0

    <0.081

    <0.11

    0

    Totals

    346

    0

    Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Chloride

    D002A

    250 mg Cl/l

    72

    0

    51

    86

    Sulphate

    A007

    250 mg SO4/l

    72

    0

    44

    100

    Total Organic Carbon

    A017

    No abnormal change

    346

    N/A

    <0.2

    4.1

    Totals

    490

    0

    Table 9: Quality of water at consumer’s tap (zones) – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply point with failures

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    128

    0

    <0.079

    <0.2

    0

    Antimony

    B008A

    5 µg Sb/l

    875

    0

    <0.16

    0.5624

    0

    Arsenic (Total)

    B001A

    10 µg As/l

    875

    0

    <0.046

    1.4

    0

    Benzene (Total)

    F002

    1 µg/l

    128

    0

    <0.03

    <0.041

    0

    Benzo[a]Pyrene (Total)

    D007

    0.01 µg/l

    875

    0

    <0.0019

    <0.0019

    0

    Boron

    D005A

    1 mg B/l

    675

    0

    <0.0064

    0.1048

    0

    Bromate

    F003

    10 µg BrO3/l

    875

    0

    <0.99

    2.9

    0

    Cadmium (Total)

    B002

    5 µg Cd/l

    875

    0

    <0.018

    0.05996

    0

    Chromium (Total)

    B004

    50 µg Cr/l

    875

    0

    <0.17

    0.3024

    0

    Copper (Total)

    A024A

    2 mg Cu/l

    875

    0

    <0.0014

    0.47

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    128

    0

    <5.5

    14.84

    0

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    11,494

    2

    0

    0

    2

    Enterococci (Confirmed)

    C003

    0 number/100 ml

    875

    0

    0

    0

    0

    Fluoride (Fluoridated)

    A027A

    1.2 mg F/l

    80

    35

    <0.06

    1

    8

    Fluoride (Total)

    A027

    1.5 mg F/l

    675

    0

    <0.06

    1

    0

    Lead (10 – will apply 25.12.2013)

    B007B

    10 µg Pb/l

    875

    4

    <0.065

    7.4

    4

    Mercury (Total)

    B005

    1 µg Hg/l 

    128

    0

    <0.022

    0.03384

    0

    Nickel (Total)

    B006A

    20 µg Ni/l

    875

    6

    0.11

    15.24

    6

    Nitrate (Total)

    A012

    50 mg NO3/l

    2,240

    0

    <0.91

    41

    0

    Nitrite – Consumer’s Taps

    A013A

    0.5 mg NO2/l

    2,240

    0

    <0.0035

    0.35

    0

    Nitrite/Nitrate formula

    A013C

    1 mg/l

    2,240

    0

    <0.019

    <0.82

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    128

    0

    0

    0.098355

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    128

    0

    <0.0036

    0.006656

    0

    Pesticides 2 4-DB

    P082

    0.1 µg/l

    127

    0

    <0.012

    <0.012

    0

    Pesticides 2,4,5-T

    P076

    0.1 µg/l

    127

    0

    <0.0044

    <0.0044

    0

    Pesticides Aldrin

    P002

    0.03 µg/l

    128

    0

    <0.0025

    <0.0025

    0

    Pesticides Aminomethylphosphonic acid

    P273

    0.1 µg/l

    128

    0

    <0.0093

    <0.06312

    0

    Pesticides Asulam

    P133

    0.1 µg/l

    128

    0

    <0.017

    <0.07021

    0

    Pesticides Benazolin (Total)

    P138

    0.1 µg/l

    1

    0

    <0.013

    <0.013

    0

    Pesticides Bentazone

    P006

    0.1 µg/l

    128

    0

    <0.0025

    0.01371

    0

    Pesticides Carbetamide 

    P010

    0.1 µg/l

    128

    0

    <0.0083

    <0.0083

    0

    Pesticides Chloridazon

    P162

    0.1 µg/l

    127

    0

    <0.0048

    <0.0048

    0

    Pesticides Chlormequat

    P163

    0.1 µg/l

    1

    0

    <0.02

    <0.02

    0

    Pesticides Chlorothalonil

    P015

    0.1 µg/l

    127

    0

    <0.0071

    <0.0071

    0

    Pesticides Chlortoluron

    P014

    0.1 µg/l

    128

    0

    <0.0031

    0.003726

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    128

    0

    <0.013

    0.05565

    0

    Pesticides Cypermethrin

    P094

    0.1 µg/l

    1

    0

    <0.016

    <0.016

    0

    Pesticides Diazinon

    P024

    0.1 µg/l

    1

    0

    <0.0094

    <0.0094

    0

    Pesticides Dicamba

    P025

    0.1 µg/l

    127

    0

    <0.017

    <0.017

    0

    Pesticides Dichlorprop

    P026

    0.1 µg/l

    127

    0

    <0.0041

    <0.0041

    0

    Pesticides Dieldrin

    P028

    0.03 µg/l

    128

    0

    <0.0019

    <0.0019

    0

    Pesticides Diflufenican

    P157

    0.1 µg/l

    128

    0

    <0.0072

    <0.0086

    0

    Pesticides Diuron

    P032

    0.1 µg/l

    128

    0

    <0.0055

    <0.0055

    0

    Pesticides Ethofumersate

    P221

    0.1 µg/l

    128

    0

    <0.007

    <0.007

    0

    Pesticides Fenpropimorph

    P037

    0.1 µg/l

    1

    0

    <0.0089

    <0.0089

    0

    Pesticides Flufenacet

    P230

    0.1 µg/l

    127

    0

    <0.0052

    0.01992

    0

    Pesticides Fluroxypyr

    P040

    0.1 µg/l

    128

    0

    <0.018

    <0.018

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    128

    0

    <0.0077

    <0.0079

    0

    Pesticides Heptachlor

    P043

    0.03 µg/l

    128

    0

    <0.0026

    <0.0026

    0

    Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

    P044

    0.03 µg/l

    128

    0

    0

    0

    0

    Pesticides Hexachlorobenzene

    P045

    0.1 µg/l

    127

    0

    <0.0065

    <0.0065

    0

    Pesticides Isoproturon

    P048

    0.1 µg/l

    128

    0

    <0.0025

    0.005981

    0

    Pesticides Lenacil

    P109

    0.1 µg/l

    127

    0

    <0.0057

    <0.0057

    0

    Pesticides Linuron

    P051

    0.1 µg/l

    127

    0

    <0.0034

    <0.0034

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    128

    0

    <0.0019

    <0.0019

    0

    Pesticides MCPB

    P055

    0.1 µg/l

    1

    0

    <0.014

    <0.014

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    128

    0

    <0.0041

    0.008494

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    128

    0

    <0.021

    0.04639

    0

    Pesticides Metamitron

    P194

    0.1 µg/l

    128

    0

    <0.0074

    <0.0074

    0

    Pesticides Metazachlor

    P203

    0.1 µg/l 

    128

    0

    <0.01

    <0.015

    0

    Pesticides Oxamyl

    P263

    0.1 µg/l

    127

    0

    <0.0023

    <0.03956

    0

    Pesticides Pendimethalin

    P118

    0.1 µg/l

    128

    0

    <0.0064

    <0.0082

    0

    Pesticides Pentachlorophenol

    P060

    0.1 µg/l

    127

    0

    <0.0062

    <0.0062

    0

    Pesticides Picloram (Total)

    P122

    0.1 µg/l

    128

    0

    <0.012

    <0.012

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    128

    0

    <0.0072

    0.04181

    0

    Pesticides Quinmerac

    P224

    0.1 µg/l

    128

    0

    <0.0052

    <0.01071

    0

    Pesticides Tebuconazole

    P177

    0.1 µg/l

    127

    0

    <0.0039

    <0.0039

    0

    Pesticides Terbutryn

    P077

    0.1 µg/l

    127

    0

    <0.0047

    <0.0073

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    128

    0

    <0.012

    <0.012

    0

    Polycyclic Aromatic Hydrocarbons (Total by Calculation)

    B011F

    0.1 µg/l

    875

    0

    0

    0

    0

    Selenium (Total)

    B009

    10 µg Se/l

    875

    0

    <0.83

    2.572

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    128

    0

    0

    0

    0

    Trihalomethanes (Total by Calculation)

    D011

    100 µg/l

    875

    0

    0

    56.24

    0

    Totals

    37,027

    47

    Table 10: Quality of water at consumer’s tap (zones) – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    No. of zones failing standard

    Aluminium (Total)

    A021

    200 µg Al/l

    4,097

    1

    <3.9

    57.02

    1

    Colour

    A001

    20 mg/l Pt/Co

    4,163

    0

    <0.81

    3.4

    0

    Iron (Total)

    A022

    200 µg Fe/l

    4,097

    16

    <2.3

    120

    14

    Manganese (Total)

    A023

    50 µg Mn/l

    4,053

    1

    <0.28

    6.492

    1

    Odour

    A003

    0 Dilution number at 25°C

    4,162

    20

    0

    0

    16

    Sodium (Total)

    A009

    200 mg Na/l

    875

    0

    2.7

    70

    0

    Taste (Taste Quant)

    A004

    0 Dilution number at 25°C

    4,157

    7

    0

    0

    7

    Tetrachloromethane (Total)

    D008

    3 µg/l

    128

    0

    <0.081

    <0.11

    0

    Turbidity

    A002

    4 NTU

    4,162

    1

    <0.09

    0.5337

    1

    Totals

    29,894

    46

    Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Ammonium (Total)

    A014

    0.5 mg NH4/l

    4,102

    1

    <0.014

    0.26

    Chloride

    D002A

    250 mg Cl/l

    675

    0

    3.904

    120

    Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    4,054

    4

    0

    0

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    11,494

    19

    0

    0

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    4,163

    N/A

    0

    91

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    4,163

    0

    120

    1000

    Gross Alpha

    F004

    0.1 Bq/l

    8

    0

    <0.02

    0.088

    Gross Beta

    F005

    1 Bq/l

    8

    0

    0.134

    0.527

    Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

    A006

    6.5 – 9.5 pH Value

    4,613

    0

    7

    8

    Residual Disinfectant – Free

    C009

    No abnormal change

    6,636

    N/A

    <0.05

    0.8763

    Residual Disinfectant – Total

    C010

    No abnormal change

    11,492

    N/A

    0.09983

    1.01

    Sulphate

    A007

    250 mg SO4/l

    675

    0

    6.1

    170

    Total Organic Carbon

    A017

    No abnormal change

    128

    N/A

    0.7361

    4

    Totals

    51,761

    24

    Flooding can be a prevalent problem in England and Wales, with one in six homes at risk to flooding. Not only can flooding cause unrepairable damage to properties, it may also result in contaminants entering the water supply network.

    How do I prepare for a flood?

    If you believe your area is at risk you can check for any potential flood warnings at the GOV UK website and sign up for free flood warning messages from the Environment Agency via text, phone or email. If you are at risk it is recommended you create a personal flood plan.

    Who is responsible for managing flood risk?

    While Flooding is often an unavoidable phenomenon, local authorities and the Environment Agency are in charge in managing flooding risks to mitigate the problem, details of their work can be found on the Local Government website.

    What should I do if my tap water may be contaminated?

    The quality of your tap water is the responsibility of your water company supervised by the Drinking Water Inspectorate (DWI). In most flooding circumstances the main supply is unaffected and so is safe to drink, however if you notice a change in quality – such as discolouration or a change in taste or smell, or unsure, call your water company. While waiting for confirmation if the main supply has been affected, boil all intended water (and let it cool to avoid scalding) or use bottled water. It is also your local water company’s responsibility to provide alternative supplies should the main supply be contaminated. Further information regarding how to boil water and other water usage is provided by UK Health Security Agency.

    What if my water comes from a private supply network?

    If your water comes from a private supply network such as a well or spring, then check that this hasn’t been affected by flooding before any usage. If you believe that the supply network has been affected or unsure, avoid all usage and use alternative supplies while waiting for confirmation or in doubt.

    CAM (Cambridge Water Plc)

    Report Data Range: For the whole year 2021

    Table 1: Quality of water leaving service treatment works – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    Nitrite (Total)

    A013B

    0.1 mg NO2/l

    142

    0

    <0.006

    <0.006

    0

    Totals

    142

    0

    Table 2: Quality of water leaving service treatment works – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    2,697

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    2,697

    0

    0

    0

    0

    Totals

    5,394

    0

    Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    2,697

    N/A

    0

    5

    Residual Disinfectant – Free

    C009

    No abnormal change

    2,697

    N/A

    0.08

    0.86

    Turbidity – Indicator

    A002A

    1 NTU

    2,697

    0

    <0.1

    0.1

    Totals

    8,091

    0

    Table 4: Quality of water leaving service reservoirs – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of reservoirs failing standard

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    1,490

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    1,488

    0

    0

    0

    0

    Totals:

    2,978

    0

    Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    1,490

    N/A

    0

    18

    Residual Disinfectant – Free

    C009

    No abnormal change

    1,490

    N/A

    0.03

    0.2309

    Totals:

    2,980

    0

    Table 6: Quality of water leaving bulk supply points – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply point with failures

    Bromate

    F003

    10 µg BrO3/l

    143

    0

    <0.8

    0.956

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    127

    0

    0

    0.05672

    0

    Pesticides Aldrin

    P002

    0.03 µg/l

    24

    0

    <0.007

    <0.007

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    47

    0

    0.002

    0.019

    0

    Pesticides Bentazone

    P006

    0.1 µg/l

    32

    0

    <0.007

    0.051

    0

    Pesticides Bromacil

    P086

    0.1 µg/l

    12

    0

    <0.003

    <0.003

    0

    Pesticides Chlortoluron

    P014

    0.1 µg/l

    24

    0

    <0.003

    0.007

    0

    Pesticides Dieldrin

    P028

    0.03 µg/l

    24

    0

    <0.007

    <0.007

    0

    Pesticides Diuron

    P032

    0.1 µg/l

    28

    0

    <0.004

    0.006

    0

    Pesticides Heptachlor

    P043

    0.03 µg/l

    32

    0

    <0.008

    <0.008

    0

    Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

    P044

    0.03 µg/l

    8

    0

    <0.005

    <0.005

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    16

    0

    <0.008

    <0.008

    0

    Pesticides Propazine

    P066

    0.1 µg/l

    4

    0

    <0.002

    <0.002

    0

    Pesticides Propiconazole

    P068

    0.1 µg/l

    8

    0

    <0.008

    <0.008

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    8

    0

    <0.005

    <0.005

    0

    Pesticides Simazine

    P073

    0.1 µg/l

    77

    0

    <0.003

    0.01

    0

    Pesticides Trietazine

    P132

    0.1 µg/l

    16

    0

    <0.004

    0.009

    0

    Totals

    630

    0

    Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Clostridium Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    142

    0

    0

    0

    Gross Alpha

    F004

    0.1 Bq/l

    8

    0

    <0.02

    0.07

    Gross Beta

    F005

    1 Bq/l

    8

    0

    <0.28

    <0.28

    Totals

    158

    0

    Table 9: Quality of water at consumer’s tap (zones) – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of zones failing standard

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    72

    0

    <0.12

    <0.12

    0

    Antimony

    B008A

    5 µg Sb/l

    74

    0

    <0.2

    <0.2

    0

    Arsenic (Total)

    B001A

    10 µg As/l

    74

    0

    <1

    <1

    0

    Benzene (Total)

    F002

    1 µg/l

    72

    0

    <0.02

    <0.02

    0

    Benzo[a]Pyrene (Total)

    D007

    0.01 µg/l

    75

    0

    <0.003

    <0.003

    0

    Boron

    D005A

    1 mg B/l

    74

    0

    <0.04

    0.077

    0

    Bromate

    F003

    10 µg BrO3/l

    2

    0

    <0.8

    <0.8

    0

    Cadmium (Total)

    B002

    5 µg Cd/l

    74

    0

    <0.12

    <0.12

    0

    Chromium (Total)

    B004

    50 µg Cr/l

    74

    0

    <0.5

    0.9

    0

    Copper (Total)

    A024A

    2 mg Cu/l

    74

    0

    <0.008

    0.978

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    74

    0

    <2

    <5

    0

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    1,028

    0

    0

    0

    0

    Enterococci (Confirmed)

    C003

    0 number/100 ml

    74

    0

    0

    0

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    75

    0

    0.086

    0.214

    0

    Lead (10 – will apply 25.12.2013)

    B007B

    10 µg Pb/l

    74

    0

    <0.9

    5.7

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    74

    0

    <0.04

    0.05

    0

    Nickel (Total) 

    B006A 

    20 µg Ni/l

    74

    1

    1.1

    27.5

    1

    Nitrate (Total)

    A012

    50 mg NO3/l

    74

    0

    30

    44.3

    0

    Nitrite – Consumer’s Taps

    A013A

    0.5 mg NO2/l

    75

    0

    <0.003

    0.006

    0

    Nitrite/Nitrate formula

    A013C

    1 mg/l

    74

    0

    0.601

    0.887

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    2

    0

    0.003

    0.029

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    1

    0

    <0.007

    <0.007

    0

    Pesticides 2,4,5-T

    P020

    0.1 µg/l

    1

    0

    <0.007

    <0.007

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    2

    0

    0.003

    0.009

    0

    Pesticides Carbendazim (Total)

    P150

    0.1 µg/l

    1

    0

    <0.001

    <0.001

    0

    Pesticides Carbetamide 

    P010

    0.1 µg/l

    1

    0

    <0.002

    <0.002

    0

    Pesticides Chlortoluron

    P014

    0.1 µg/l

    1

    0

    <0.003

    <0.003

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    2

    0

    <0.007

    <0.007

    0

    Pesticides Desethylatrazine

    P182

    0.1 µg/l

    1

    0

    <0.01

    <0.01

    0

    Pesticides Diuron

    P032

    0.1 µg/l

    1

    0

    <0.004

    <0.004

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l

    2

    0

    <0.008

    <0.008

    0

    Pesticides Metazachlor

    P203

    0.1 µg/l 

    1

    0

    <0.003

    <0.003

    0

    Pesticides Propazine

    P066

    0.1 µg/l

    1

    0

    <0.002

    <0.002

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    1

    0

    <0.005

    <0.005

    0

    Pesticides Quinmerac

    P244

    0.1 µg/l

    2

    0

    <0.002

    <0.002

    0

    Pesticides Simazine

    P073

    0.1 µg/l

    1

    0

    0.013

    0.013

    0

    Polycyclic Aromatic Hydrocarbons (Total by Calculation)

    B011F

    0.1 µg/l

    75

    0

    0

    0.013

    0

    Selenium (Total)

    B009

    10 µg Se/l

    74

    0

    <0.8

    1.3

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    72

    0

    0

    1.73

    0

    Trihalomethanes (Total by Calculation)

    D011

    100 µg/l

    72

    0

    1.83

    20.6

    0

    Totals

    2,676

    1

    Table 10: Quality of water at consumer’s tap (zones) – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    No. of zones failing standard

    Aluminium (Total)

    A021

    200 µg Al/l

    74

    0

    <6

    96.9

    0

    Colour

    A001

    20 mg/l Pt/Co

    350

    0

    <1

    <1

    0

    Iron (Total)

    A022

    200 µg Fe/l

    74

    0

    <4

    17.2

    0

    Manganese (Total)

    A023

    50 µg Mn/l

    74

    0

    <1.7

    <1.7

    0

    Odour

    A003

    0 Dilution number at 25°C

    352

    0

    0

    0

    0

    Sodium (Total)

    A009

    200 mg Na/l

    74

    0

    4.2

    48.3

    0

    Taste (Taste Quant)

    A004

    0 Dilution number at 25°C

    352

    0

    0

    0

    0

    Tetrachloromethane (Total)

    D008

    3 µg/l

    72

    0

    <0.11

    <0.11

    0

    Turbidity

    A002

    4 NTU

    350

    0

    <0.1

    <0.1647

    0

    Totals

    1,772

    0

    Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Ammonium (Total)

    A014

    0.5 mg NH4/l

    350

    0

    <0.02

    0.02645

    Chloride

    D002A

    250 mg Cl/l

    74

    0

    22

    75

    Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    2

    0

    0

    0

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    1,028

    1

    0

    0

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    350

    N/A

    0

    177

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    350

    0

    529.51

    723

    Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

    A006

    6.5 – 9.5 pH Value

    350

    0

    7.1

    7.9

    Residual Disinfectant – Total

    C010

    No abnormal change

    1,028

    N/A

    0.03

    0.19

    Sulphate

    A007

    250 mg SO4/l

    74

    0

    23.1

    52.8

    Total Organic Carbon

    A017

    No abnormal change

    74

    N/A

    0.4

    1.2

    Totals

    3,680

    1

    Severn Trent Water plc 

    Water supply arrangements

    Company Assets

    Number of treatment works

    92

    Number of service reservoirs 

    157

    Number of water supply zones

    89

    Length of mains pipe (km)

    16,800km

    Population Served

    Population Supplied

    3,797,000

    Number of local authorities

    41

    Water Supplied

    Water Supplied (l/day)

    950,608,000

    Percentage from surface sources

    40%

    Percentage of ground sources

    55%

    Percentage from mixed sources

    5%

    Area of supply

    Cheshire, Derbyshire, Nottinghamshire, Leicestershire, Warwickshire, Gloucestershire, Worcestershire, Shropshire, Staffordshire, West Midlands

    Consumer Contacts

    Informing Consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    961

    0.25

    2020

    897

    0.24

    2021

    900

    0.24

    Industry Average

    2021

    9,913.96

    1.22

    Acceptability of water to consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    3,066

    0.81

    2020

    3,319

    0.88

    2021

    3,036

    0.80

    Industry Average

    2021

    2,832.12

    1.08

    Complaints to the Drinking Water Inspectorate

    A total of 5 consumers of Severn Trent Water plc directly contacted DWI in 2021.

    Where does lead come from?

    Lead used to be common in the environment due to its widespread historic use in petrol, paint and water pipes. Before 1970, lead pipework was commonly used to connect properties to the mains water network. The use of lead pipes has since been banned, however many older properties that have not been modernised are likely to have lead pipework underground and/or inside the building.

    Occasionally lead occurs naturally in groundwater however, this is a rare situation in the UK and lead is not present in the water within our wider public water supply network.

    Is lead harmful?

    Lead can build up in the body and it is recommended that exposure to lead minimised as far as possible. Those at particular risk are infants (including unborn babies) and children because lead can have an adverse impact on mental development. Lead may also be factor in behavioural problems. In adults it may impair kidney, heart and circulatory health.

    How do I know if there are lead pipes in my home?

    If your home was built:

    • before 1970 – it may have lead pipes
    • after 1970 – it is unlikely to have lead pipes

    If you are unsure, you can make a simple check:

    Find your internal stop tap, where the water first comes into the property. This may be in or behind the cupboards in your kitchen or a downstairs toilet. Unpainted lead pipes appear dull grey and often have a swollen joint next to the tap. The metal is soft and, if gently scraped with a coin, you will see the shiny, silver-coloured metal beneath. Wear disposable gloves while you do this and be careful not to breathe in any dust.

    Other pipe materials in common use are:

    • copper – bright, hard and dull brown
    • iron – dark, very hard and may be rusty
    • plastic – typically blue but if older it may be grey or black.

    How does lead get into drinking water?

    Lead from pipework can dissolve into the water whilst it stands in the pipe. Therefore, if you have lead pipework, the chances are there will be some lead in your drinking water. The concentration of lead may depend on the following:

    • How long the water has been standing in the pipe
    • The condition of the lead pipework
    • The temperature of the water; more lead will dissolve during the summer and autumn months
    • Water hardness; harder water tends to form a protective scale over the surface of the pipe which can reduce the concentration of lead in the water.

    Where a risk of lead exists, water companies treat the water with orthophosphate to reduce the problem significantly. None the less, particles of lead may build up in these older pipes and intermittently appear in tap water.

    A less common cause of lead in drinking water is the illegal use of lead-based solder to join sections of copper pipe. Lead solder is still permitted for use in closed central heating systems and mistakes occasionally happen whereby unqualified plumbers or householders use lead solder on drinking water pipes. Older brass fittings can also be a source of lead.

    Disturbing or working on lead pipes can cause the concentration of lead in drinking water to temporarily increase. Flush the tap well for at least 10 minutes after carrying out any work on a lead pipe.

    For all these reasons, lead in drinking water at a particular property may be present and if so, actions should be taken to reduce this as far as possible.

    How do I reduce lead levels in my drinking water?

    For drinking and cooking, run the tap to clear any water that has been standing in the pipework for while, for example, overnight. A washing up bowl full is normally enough to clear the pipe of standing water, although if you have long service pipe you may need to run the tap for longer. Check to see if you notice the temperature of the water drop as the mains water comes through (run the tap over your fingers and you should notice the change of temperature as fresh mains water arrives). You can then use the kitchen tap as normal.

    This short-term measure will protect you and your family, but if there are lead pipes or another source of lead present, these should be replaced as soon as possible.

    How can I find out if there is lead in my drinking water?

    If you suspect that your home has lead pipes you can ask your water company to test the water at your kitchen tap. If the water company investigates and finds lead pipes or another source of lead in the plumbing system, they should provide you with written advice on what to do.

    Who is responsible for the pipework?

    The part of the service pipe that links the water main in the street to the stop valve outside your property belongs to the water company. This is known as the communication pipe, see the diagram below.

    The part of the service pipe leading from the stop valve outside your property to the point where it enters your home is the responsibility of the owner. This is known as the private or supply pipe.

    All the plumbing inside your home to the kitchen tap is the responsibility of the property owner.

    Picture showing boundaries of the communication pipe and supply pipe

    Diagram 1 showing boundary between communication and supply pipes.

    Replacing Lead Pipework

    If you are planning on replacing your pipework, we recommend that you employ a qualified plumber to carry out any plumbing work, for example one who is accredited through the WaterSafe scheme. Refer to the WaterSafe website and see also our Advice Leaflet for finding a plumber.

    When arranging this you should also notify your water company because they are legally required to replace their communication pipe, if it is made of lead and is at risk of contributing to the amount of lead in the drinking water supply.

    I am buying a property

    Ask your surveyor to check the nature and condition of the outside and internal pipes as part of the survey, making special mention of lead. Purchasers increasingly make the cost of removing lead pipes part of their negotiations with vendors as to sale price.

    A lead pipe showing a swollen 'lead wipe' joint

    Diagram 2 A lead pipe showing a swollen ‘lead wipe’ joint.

    This accessibility statement applies to https://dwi.gov.uk

    This website is run by Drinking Water Inspectorate. We want as many people as possible to be able to use this website. For example, that means you should be able to:

    • change colours, contrast levels and fonts
    • zoom in up to 300% without the text spilling off the screen
    • navigate as much of the website as possible using just a keyboard
    • navigate as much of the website as possible using speech recognition software
    • listen to most of the website using a screen reader (including the most recent versions of JAWS, NVDA and VoiceOver)

    Feedback and contact information

    If you need information on this website in a different format, for example an accessible PDF, large print, easy read, audio recording or braille:

    We’ll consider your request and get back to you in 14 days.

    Reporting accessibility problems with this website

    We’re always looking to improve the accessibility of this website. If you find any problems not listed on this page or think we’re not meeting accessibility requirements, contact: dwi.enquiries@defra.gov.uk.

    Enforcement procedure

    The Equality and Human Rights Commission (EHRC) is responsible for enforcing the Public Sector Bodies (Websites and Mobile Applications) (No. 2) Accessibility Regulations 2018 (the ‘accessibility regulations’). If you’re not happy with how we respond to your complaint, contact the Equality Advisory and Support Service (EASS).

    Technical information about this website’s accessibility

    Drinking Water Inspectorate is committed to making its website accessible, in accordance with the Public Sector Bodies (Websites and Mobile Applications) (No. 2) Accessibility Regulations 2018.

    Compliance status This website is partially compliant with the Web Content Accessibility Guidelines version 2.1 AA standard, due to the non-compliances and exemptions listed below.

    Non-accessible content

    Non-accessible content

    The content listed below is non-accessible for the following reasons.

    Non-compliance with the accessibility regulations

    The label on the cookie switch and the read out are not the same. Screen reader users may be confused about what they are agreeing to. It is not possible to change cookie settings using JAWS screen reader or Dragon Naturally Speaking speech recognition software.

    There are some ambiguous or unclear link text. Multiple links that point to the page have the different link text.

    All our map images do not have alternative text. None of the text on the maps is accessible to screen readers.

    Some headings do not clearly describe what content follows.

    When the home icon has focus, the contrast between white and yellow is not enough and makes the icon hard to see.

    When you select the link ‘View cookies’ on the cookie banner, a modal popup appears but this is not announced to screen reader users.

    If the user searches but does not type a search term, they are not alerted and they may assume that the search results are for what they intended to type.

    Some images do not have a text alternative, so people using a screen reader cannot access the information. This fails WCAG 2.1 success criterion 1.1.1 (non-text content).

    We plan to add text alternatives for all images by September 2023. When we publish new content, we’ll make sure our use of images meets accessibility standards.

    Disproportionate burden

    Some of our information is specialist to the water industry and highly technical.  We will provide accessible content for reports on request and will prioritise information for consumers.   

    Content that’s not within the scope of the accessibility regulations

    The accessibility regulations do not require us to fix PDFs or other documents published before 23 September 2018 if they’re not essential to providing our services.

    PDFs and non-HTML documents

    Some of our PDFs and Word documents are essential to providing our services. For example, we have PDFs with information on how users can access our services, and forms published as Word documents for product approval. We are in the process of scoping an upgrade to our product approval system to make it more accessible for all our users.

    The accessibility regulations do not require us to fix PDFs or other documents published before 23 September 2018 if they’re not essential to providing our services. For example, we do not plan to fix research reports published prior to 2018.

    Any new PDFs or Word documents we create ourselves will meet accessibility standards.  

    What we’re doing to improve accessibility

    We have been working with our website designer to improve the accessibility of the website and fix the issues listed above, and we are currently reviewing how far we have got with that.

    We have used a variety of techniques to analyse the website focusing on critical functionality, and we are committed to checking functionality as we make future changes.

    We are working on the website content to improve its accessibility. We have updated most of our consumer leaflets and made them into accessible PDFs and HTML pages. We are working on the remaining leaflets and aim to have them all completed by December 2022. 

    All research commissioned since January 2020 will report in fully accessible pdf format. 

    The annual Chief Inspector’s Reports (England and Wales, public and private supplies) are produced in an accessible format since 2020.

    Content that’s not within the scope of the accessibility regulations

    The accessibility regulations do not require us to fix PDFs or other documents published before 23 September 2018 if they’re not essential to providing our services.

    Preparation of this accessibility statement

    This statement was prepared on 20 November 2020. It was last reviewed on 10 January 2023.

    This website was last tested on 13 to 26 May 2021. The test was carried out by Defra digital services.

    South West & Bournemouth Water Ltd

    Water supply arrangements

    Company Assets

    Number of treatment works

    92

    Number of service reservoirs 

    157

    Number of water supply zones

    89

    Length of mains pipe (km)

    16,800km

    Population Served

    Population Supplied

    3,797,000

    Number of local authorities

    41

    Water Supplied

    Water Supplied (l/day)

    950,608,000

    Percentage from surface sources

    40%

    Percentage of ground sources

    55%

    Percentage from mixed sources

    5%

    Area of supply

    Dorset, Cornwall, Devon, Somerset, Hampshire

    Consumer Contacts

    Informing Consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    961

    0.25

    2020

    897

    0.24

    2021

    900

    0.24

    Industry Average

    2021

    9,913.96

    1.22

    Acceptability of water to consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    3,066

    0.81

    2020

    3,319

    0.88

    2021

    3,036

    0.80

    Industry Average

    2021

    2,832.12

    1.08

    Complaints to the Drinking Water Inspectorate

    A total of 1 consumer of South West & Bournemouth Water Ltd directly contacted DWI in 2021.

    Overview

    The Triennial and Annual Drinking Water reports published by the Chief Inspector have shown that the industry figure for public water supply compliance with the regulations is well above 99.9% which indicates that the drinking water supply in England and Wales is excellent.

    Mains Water

    If you have concerns about the quality of your tap water, you should first approach your water supplier and explain the problem to them. If you are unsure who your water supplier is, you can find out by entering your postcode on the Water UK website. Companies will normally take a sample in response to a complaint from a consumer depending on the nature of it. Additionally, they test water daily in your area and will give you the results free of charge on request. This is also available on many water company websites.

    Private Water Supplies

    Your local authority will provide advice on any testing and arrange for this to be carried out on your behalf. If you are unsure who your local authority is, please visit the GOV UK website.

    Private Testing

    The last option is to have the water tested privately for which there will be a charge. You can find your nearest approved laboratory by visiting the UKAS website.

    Thames Water Utilities Ltd

    Water supply arrangements

    Company Assets

    Number of treatment works

    92

    Number of service reservoirs 

    157

    Number of water supply zones

    89

    Length of mains pipe (km)

    16,800km

    Population Served

    Population Supplied

    3,797,000

    Number of local authorities

    41

    Water Supplied

    Water Supplied (l/day)

    950,608,000

    Percentage from surface sources

    40%

    Percentage of ground sources

    55%

    Percentage from mixed sources

    5%

    Area of supply

    Barnet, Bexley, Brent, Bromley, Buckinghamshire, Camden, City of London, Croydon, Ealing, Enfield, Essex, Gloucestershire, Greenwich, Hackney, Hammersmith and Fulham, Hampshire, Haringey, Hertfordshire, Hounslow, Islington, Kensington and Chelsea, Kent, Kingston upon Thames, Lambeth, Lewisham, Merton, Newham, Oxfordshire, Reading, Redbridge, Richmond upon Thames, Slough, Southwark, Surrey, Swindon, Tower Hamlets, Waltham Forest, Wandsworth, West Berkshire, Westminster, Wiltshire, Windsor and Maidenhead, Wokingham  

    Consumer Contacts

    Informing Consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    961

    0.25

    2020

    897

    0.24

    2021

    900

    0.24

    Industry Average

    2021

    9,913.96

    1.22

    Acceptability of water to consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    3,066

    0.81

    2020

    3,319

    0.88

    2021

    3,036

    0.80

    Industry Average

    2021

    2,832.12

    1.08

    Complaints to the Drinking Water Inspectorate

    A total of 6 consumers of Thames Water Utilities Ltd directly contacted DWI in 2021.

    United Utilities Water Ltd

    Water supply arrangements

    Company Assets

    Number of treatment works

    92

    Number of service reservoirs 

    157

    Number of water supply zones

    89

    Length of mains pipe (km)

    16,800km

    Population Served

    Population Supplied

    3,797,000

    Number of local authorities

    41

    Water Supplied

    Water Supplied (l/day)

    950,608,000

    Percentage from surface sources

    40%

    Percentage of ground sources

    55%

    Percentage from mixed sources

    5%

    Area of supply

    Blackburn with Darwen, Blackpool, Bolton, Bury, Cheshire East, Cheshire West and Chester, Cumbria, Derbyshire, Halton, Knowsley, Lancashire, Liverpool, Manchester, Oldham, Rochdale, Salford, Sefton, St. Helens, Stockport, Tameside, Trafford, Warrington, Wigan, Wirral 

    Consumer Contacts

    Informing Consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    961

    0.25

    2020

    897

    0.24

    2021

    900

    0.24

    Industry Average

    2021

    9,913.96

    1.22

    Acceptability of water to consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    3,066

    0.81

    2020

    3,319

    0.88

    2021

    3,036

    0.80

    Industry Average

    2021

    2,832.12

    1.08

    Complaints to the Drinking Water Inspectorate

    A total of 3 consumers of Thames Water Utilities Ltd directly contacted DWI in 2021.

    What are PFAS?

    PFAS (per-and poly fluoroalkyl substances) is a chemical family consisting of at least 5,000 individual substances. They are sometimes referred to as ‘forever chemicals’ because of their persistence in the environment.

    In manufacturing, PFAS are favoured for their durability and useful properties such as non-stick, water repellence and anti-grease. PFAS are used in the manufacture of many domestic products, including:

    • skin creams and cosmetics,
    • car and floor polish,
    • rinse aid for dishwashers,
    • textile and fabric treatments,
    • food packaging and microwave popcorn bags,
    • baking equipment,
    • frying pans,
    • outdoor clothing and shoes.

    They also have many and widespread uses in industry, including in firefighting foam. The properties of these substances mean that they are very resistant to biodegradation.

    In recent years, they have received increased interest from both a research and regulatory perspective to better understand and mitigate the potential for any public health impacts.

    Chemistry of PFAS

    PFAS are typically described as comprising a group of compounds having carbon atoms linked to each other and bonded to fluorine atoms at most, or all the carbon bonding sites. These can be classified as polymers and non-polymers.

    Polymers

    Fluoropolymers are an example of polymers. Examples include PTFE, FEP, ETFE and PFA, which have been referred to as ‘polymers of low concern’ because they have high molecular weight and are extremely stable.

    Non-polymers

    Most research interest has been in the behaviour of non-polymer PFAS, due to them being the most commonly detected so far in humans, biota, and other environmental media and appear to be relatively more abundant at PFAS investigation sites.

    Are PFAS harmful?

    As a result of their widespread use and persistence, PFAS are being found to be present in many different environments. Toxicity data is not available for many PFAS.

    Some PFAS, such as perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS), have been associated with adverse effects in animal and human studies at sufficient levels of exposure. This has led to the restricted use of some of these substances in a variety of global markets. Perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS), have been restricted in England and Wales through UK REACH, the regulatory framework for Registration, Evaluation, Authorisation and Restriction of Chemicals.

    The Environment Agency (EA) is currently undertaking surveillance of PFAS as part of their groundwater quality monitoring network, and water companies are also monitoring for a range of PFAS in the raw water. The Drinking Water Inspectorate (DWI) is currently engaged with water companies in England and Wales to improve knowledge about the location, types and levels of specific PFAS. These PFAS may have entered the water environment due to historical and/or current industrial practices that produce products for all areas of modern society. Drinking water is only one possible route of exposure to PFAS, accounting for a small proportion of the possible overall exposure alongside use of various chemical products, food and even household dust.

    Based on our current knowledge, the low levels of PFAS detected in some untreated water abstracted for public drinking water supplies has no acute or immediate impact on human health.

    Recognising the potential for longer term accumulation of some PFAS in the human body, the DWI has set guidance levels for PFAS (based on an assessment of existing scientific knowledge) that provide a precautionary margin of safety in advance of further international research results on PFAS toxicology. Water companies are required to comply with this guidance, and where necessary take specific actions such as additional treatment and/or blending with other sources to reduce PFAS prior to supply.

    Precautionary approach to regulation

    Water companies have a duty to ensure water is wholesome. There are currently no statutory standards for PFAS in drinking water England and Wales, nor is there a World Health Organisation guideline value. The DWI has taken a precautionary approach and produced tiered guideline values for water companies to adhere to.

    Other countries have also put restrictions on PFAS concentrations in drinking water and the European Union is in the process of adopting a standard of 0.1 micrograms per litre for 20 individual substances. Prior to leaving the EU the UK worked with partners towards developing the methodology and assessment approach for setting these limits. DWI considers that this approach remains valid, and that a guidance limit of 0.1 micrograms per litre for PFAS is a robust level with an appropriate margin of safety to ensure the wholesomeness of drinking water.

    The DWI is working closely with the UK Health Security Agency, the EA and government, to adopt the most up to date information regarding standards and toxicology. We continue to carry out our own research to inform our decision making. All of our research is published on our website.

    DWI guidance to water companies

    In March 2025, the DWI published updated guidance for PFAS in drinking water requiring water companies in England and Wales to monitor for a wider range of PFAS and update their risk assessments accordingly.

    The DWI guidance follows a tiered approach with a guideline value of 0.1 micrograms per litre for the sum of 48 named PFAS, which is equivalent to 0.1 parts per billion.

    Private Water Supplies

    Local authorities are responsible for identifying risks to the quality of private water supplies and will seek advice from the UK Health Security Agency when required.

    DWI has provided advice that in the first instance, it is important for local authorities to understand if any of their supplies are at high risk of the presence of PFAS. High risk supplies can then be prioritised for further action which may include sampling and analysis when it is available. The UK Health Security Agency will help them advise on any potential risks to the wholesomeness of the water.

    Owners of private supplies where the individual PFAS are detected above the guidance level of 0.1 µg/l for drinking water are advised to contact the Environmental Health Team at their local authority to discuss what these results mean for their drinking water quality.

    Sampling and Analysis

    Laboratory capacity is being expanded in England and Wales, and analytical methods are constantly being developed and improved to monitor a larger range of PFAS at ever more smaller concentrations. So far only a few of these are accredited as quantified analytical techniques (essentially techniques with a high level of accuracy, repeatability and reliability) and a Standing Committee of Analysts Blue Book method has been developed to further improve the suite analytical approaches.

    PFAS are ubiquitous, in personal care products, waterproof jackets and in sampling and laboratory equipment. Therefore, specialist PFAS free laboratory equipment is required, which has led to the current situation where only a few labs are able to analyse for PFAS with the degree of quality required.

    Is my water safe to drink?

    Drinking water in England and Wales is safe, reliable and of very high quality. Public supplies in particular are among the best in the world. Water companies carry out water safety planning and use a risk-based approach to deal with any issues before they become a problem.

    Our regulatory system is designed to protect consumers at all times. Water supplies are made safe through a combination of treatment processes and managed dilution through blending, to achieve stringent regulatory standards, before reaching the consumer’s tap. As companies carry out more extended monitoring for PFAS we are likely to detect traces in more sources. This does not mean that the water has been unwholesome. Even where a guideline standard is exceeded, this does not mean that consumer’s health has been harmed, rather that the safety margin is less than we would expect to see achieved. In such instances the water company will be required to put in more protection to meet the guideline standards or if this cannot be achieved in suitable timeframe, remove the source from supply pending further assessment of treatment options.

    By law, your water company must inform you if there is a problem with your supply which could pose a risk to health and provide alternative water while any problem is fixed.

    The DWI regulates water companies in accordance with its enforcement policy and has a range of powers to ensure risks are adequately dealt with before they become a problem, such that consumers are protected at all times.

    Security and Emergencies

    Security and Emergency Measures Direction 2022 as amended (SEMD)

    The Drinking Water Inspectorate (DWI) is the independent regulator of drinking water in England and Wales. We provide independent assurance that the privatised water industry delivers and maintains a safe, clean drinking water to consumers.

    The Security and Emergency Measures (Water and Sewerage Undertakers and Water Supply Licensees) Direction 2022 (SEMD)(PDF 222KB) is the principal general direction issued by the Secretary of State and Welsh Ministers under Section 208 of the Water Industry Act 1991 (the Act).

    This was subsequently amended in 2024 with the The Security and Emergency Measures (water and
    sewerage undertakers and water supply licensees)(Amendment and Revocation) Direction 2024
    .

    Undertakers and licensees are required to maintain a water supply and/or sewerage system in the interests of national security or to mitigate the effects of any civil emergency which may occur.

    The DWI, on behalf of the Secretary of State and Welsh Ministers, are responsible for the regulation of the SEMD for companies who are wholly or mainly in England and Wales. This includes reviewing companies’ annual self-assessments and all National Infrastructure (NI) audits including Critical National Infrastructure (CNI), and any necessary compliance and enforcement actions.

    SEMD Enforcement Policy

    Help

    The Drinking Water Inspectorate

    Find our contact details on our Contact us page.

    Read our Privacy Policy.

    Read our Accessibility Statement.

    Annex C – Parameter Code List

    This is the live parameter list which should be referred to at all times, for ease of use an excel version is provided below, which will be updated periodically.

    Link to spreadsheet – Annex C

    UUT (United Utilities Water Plc)

    Report Data Range: For the whole year 2021

    Table 1: Quality of water leaving service treatment works – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    Nitrite (Total)

    A013B

    0.1 mg NO2/l

    682

    0

    <0.0062

    <0.0115

    0

    Totals

    682

    0

    Table 2: Quality of water leaving service treatment works – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    16,270

    1

    0

    0

    1

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    16,272

    5

    0

    0

    5

    Totals

    32,542

    6

    Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    16,267

    N/A

    0

    1

    Residual Disinfectant – Free

    C009

    No abnormal change

    16,248

    N/A

    0.49

    1.53

    Residual Disinfectant – Total

    C010

    No abnormal change

    16,251

    N/A

    0.54

    1.6

    Turbidity – Indicator

    A002A

    1 NTU

    16,249

    1

    <0.16

    <0.24

    Totals

    65,015

    1

    Table 4: Quality of water leaving service reservoirs – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of reservoirs failing standard

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    17,939

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    17,939

    5

    0

    0

    0

    Totals:

    35,878

    5

    Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    17,936

    N/A

    0

    9

    Residual Disinfectant – Free

    C009

    No abnormal change

    17,952

    N/A

    0.21

    1.24

    Residual Disinfectant – Total

    C010

    No abnormal change

    17,933

    N/A

    0.28

    1.29

    Totals:

    53,821

    0

    Table 6: Quality of water leaving bulk supply points – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply point with failures

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    691

    0

    <0.459

    <0.459

    0

    Benzene (Total)

    F002

    1 µg/l

    691

    0

    <0.157

    <0.157

    0

    Boron

    D005A

    1 mg B/l

    694

    0

    <0.0217

    0.065705

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    704

    0

    <2.33

    <3.91

    0

    Fluoride (Fluoridated)

    A027A

    1.2 mg F/l

    24

    0

    0.89

    1.04

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    701

    0

    <0.01

    1.01

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    689

    0

    <0.04

    <0.05

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    341

    0

    0

    0.027432

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    138

    0

    <0.012

    <0.01788

    0

    Pesticides 2 4-DB

    P082

    0.1 µg/l

    49

    0

    <0.021

    <0.022

    0

    Pesticides Aldrin

    P002

    0.03 µg/l

    2

    0

    <0.0025

    <0.0025

    0

    Pesticides Asulam

    P133

    0.1 µg/l

    58

    0

    <0.0047

    <0.0056

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    7

    0

    <0.009

    <0.009

    0

    Pesticides Bromoxynil

    P008

    0.1 µg/l

    1

    0

    <0.011

    <0.011

    0

    Pesticides Carbetamide

    P010

    0.1 µg/l

    57

    0

    <0.01

    <0.02

    0

    Pesticides Chlortoluron

    P014

    0.1 µg/l

    40

    0

    <0.007

    <0.014

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    140

    0

    <0.011

    0.01495

    0

    Pesticides Diazinon

    P024

    0.1 µg/l

    117

    0

    <0.008

    <0.01456

    0

    Pesticides Dicamba

    P025

    0.1 µg/l

    34

    0

    <0.013

    <0.019

    0

    Pesticides Dichlorprop

    P026

    0.1 µg/l

    41

    0

    <0.013

    <0.018

    0

    Pesticides Dieldrin

    P028

    0.03 µg/l

    2

    0

    <0.0019

    <0.0019

    0

    Pesticides Diuron

    P032

    0.1 µg/l

    56

    0

    <0.008

    <0.008

    0

    Pesticides Fluroxypyr

    P040

    0.1 µg/l

    136

    0

    <0.014

    <0.016

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    247

    0

    <0.0079

    0.018752

    0

    Pesticides Heptachlor

    P043

    0.03 µg/l

    2

    0

    <0.0026

    <0.0026

    0

    Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

    P044

    0.03 µg/l

    2

    0

    <0.0039

    <0.0039

    0

    Pesticides Isoproturon

    P048

    0.1 µg/l

    41

    0

    <0.008

    <0.016

    0

    Pesticides Linuron

    P051

    0.1 µg/l

    40

    0

    <0.01

    <0.02

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    215

    0

    <0.012

    <0.0202

    0

    Pesticides MCPB

    P055

    0.1 µg/l

    106

    0

    <0.01

    <0.01993

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    70

    0

    <0.0045

    0.008

    0

    Pesticides Metazachlor

    P203

    0.1 µg/l 

    50

    0

    <0.008

    <0.016

    0

    Pesticides Pentachlorophenol

    P060

    0.1 µg/l

    17

    0

    <0.011

    <0.021

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    25

    0

    <0.01

    <0.01

    0

    Pesticides Simazine

    P073

    0.1 µg/l

    2

    0

    <0.01

    <0.01

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    136

    0

    <0.01244

    <0.025

    0

    Radon

    F031

    100 Bq/l

    31

    0

    <1.1

    18.8

    0

    Totals

    6,398

    0

    Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Chloride

    D002A

    250 mg Cl/l

    701

    0

    4.1006

    112

    Gross Alpha

    F004

    0.1 Bq/l

    31

    0

    <0.02

    0.06

    Gross Beta

    F005

    1 Bq/l

    31

    0

    <0.02

    0.14

    Sulphate

    A007

    250 mg SO4/l

    696

    0

    1.8279

    107.3

    Total Organic Carbon

    A017

    No abnormal change

    703

    N/A

    <0.67

    2.5288

    Tritium

    F006

    100 Bq/l

    32

    0

    <10

    <10

    Totals

    2,194

    0

    Table 9: Quality of water at consumer’s tap (zones) – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply point with failures

    Antimony

    B008A

    5 µg Sb/l

    1,838

    0

    <0.31

    <0.44

    0

    Arsenic (Total)

    B001A

    10 µg As/l

    1,833

    0

    <0.09

    3.883

    0

    Benzo[a]Pyrene (Total)

    D007

    0.01 µg/l

    2,092

    1

    <0.002

    <0.002

    1

    Bromate

    F003

    10 µg BrO3/l

    1,821

    0

    <0.12

    1.849

    0

    Cadmium (Total)

    B002

    5 µg Cd/l

    1,837

    0

    <0.09

    <0.1

    0

    Chromium (Total)

    B004

    50 µg Cr/l

    1,834

    0

    <0.16

    <0.83

    0

    Copper (Total)

    A024A

    2 mg Cu/l

    1,848

    0

    <0.0031

    0.15359

    0

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    19,312

    1

    0

    0

    1

    Enterococci (Confirmed)

    C003

    0 number/100 ml

    1,828

    0

    0

    0

    0

    Fluoride (Fluoridated)

    A027A

    1.2 mg F/l

    38

    11

    0.37

    1.07

    3

    Fluoride (Total)

    A027

    1.5 mg F/l

    39

    0

    0.07

    1.07

    0

    Lead (10 – will apply 25.12.2013)

    B007B

    10 µg Pb/l

    1,842

    3

    <0.55

    4.4026

    3

    Nickel (Total)

    B006A

    20 µg Ni/l

    1,836

    5

    <0.77

    7.1878

    5

    Nitrate (Total)

    A012

    50 mg NO3/l

    2,014

    0

    <1.02

    31.665

    0

    Nitrite – Consumer’s Taps

    A013A

    0.5 mg NO2/l

    2,013

    0

    <0.0062

    <0.0115

    0

    Nitrite/Nitrate formula

    A013C

    1 mg/l

    2,013

    0

    0.014

    0.6342

    0

    Polycyclic Aromatic Hydrocarbons (Total by Calculation)

    B011F

    0.1 µg/l

    2,092

    0

    0

    0.00207

    0

    Selenium (Total)

    B009

    10 µg Se/l

    1,835

    0

    <0.2

    <0.99

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    1,845

    0

    0

    0.32224

    0

    Trihalomethanes (Total by Calculation)

    D011

    100 µg/l

    1,851

    0

    0

    54.836

    0

    Totals

    51,661

    21

    Table 10: Quality of water at consumer’s tap (zones) – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    No. of zones failing standard

    Aluminium (Total)

    A021

    200 µg Al/l

    7,239

    6

    <2.71

    43.76

    5

    Colour

    A001

    20 mg/l Pt/Co

    7,317

    0

    <1.21

    <2.16

    0

    Iron (Total)

    A022

    200 µg Fe/l

    7,219

    22

    <2.1

    96.98

    21

    Manganese (Total)

    A023

    50 µg Mn/l

    7,224

    6

    <0.37

    9.9125

    5

    Odour

    A003

    0 Dilution number at 25°C

    7,372

    14

    0

    0

    14

    Sodium (Total)

    A009

    200 mg Na/l

    1,816

    0

    2.85

    56.083

    0

    Taste (Taste Quant)

    A004

    0 Dilution number at 25°C

    7,341

    14

    0

    0

    13

    Tetrachloromethane (Total)

    D008

    3 µg/l

    1,857

    0

    <0.06

    0.1242

    0

    Turbidity

    A002

    4 NTU

    7,280

    1

    <0.16

    <0.24

    1

    Totals

    54,665

    63

    Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Ammonium (Total)

    A014

    0.5 mg NH4/l

    2,054

    0

    <0.0154

    <0.0475

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    1,822

    9

    0

    0

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    19,311

    49

    0

    0

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    7,320

    N/A

    0

    33

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    7,290

    0

    46

    687.36

    Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

    A006

    6.5 – 9.5 pH Value

    7,259

    2

    6.89

    8.04

    Residual Disinfectant – Free

    C009

    No abnormal change

    19,353

    N/A

    0.11

    1.16

    Residual Disinfectant – Total

    C010

    No abnormal change

    19,349

    N/A

    0.21

    1.25

    Totals

    83,758

    51

    Independent Water Commission: review of the water sector – DWI Summary Response

    Drinking Water Inspectorate summary response

    Section 2: Overarching Framework for the Management of Water

    Water system outcomes

    Ensuring the continuous supply of safe and wholesome drinking water, now and in the future is the Inspectorate’s priority.

    In the UK, we are fortunate to have access to world leading drinking water quality (2024 Environmental Performance Index – Unsafe drinking water). This is a public health service, fundamental to a healthy and productive society.

    Resilience to changing pressures is an important outcome, and resilience and reliability of water supplies supports the Government’s growth agenda by supporting productivity of businesses and development of industry. Pressures include impacts of climate change, infrastructure development, population growth and demand management, sufficiency and resilience of water supplies, emerging contaminants, external threats posed by cyber and physical security of assets, as well consumer trust in drinking water.  

    Access to water for vulnerable and marginalised groups, is another key theme, together with asset health and resilience of supplies, affordability of water and water poverty. Other outcomes are:

    • drought preparedness and management, water sufficiency
    • access for those on private water supplies to connect to public supplies especially those at high risk from drought and contamination,
    • consumer confidence in drinking water removal of lead pipes from water all supplies.

    Management of water

    The Inspectorate is the competent authority for drinking water in England and Wales. 

    The Chief Inspector has an advisory role in section 86 of the Water Industry Act to advise the Secretary of State on matters of regulation and specifically that industry manages risk for the long-term benefit of supplies to consumers.

    Collaborative decision making between the Inspectorate and government officials within an agreed framework is now being enacted following EU exit. The Chief Inspector commissioned an advisory group to deliver recommendations on standards. Further work will examine other areas of drinking water policy and legislation, such as standards of wholesomeness for other domestic uses, recycling and greywater, domestic risk assessments and water fittings.

    The water sector is complex with many stakeholders across government departments, including the environment, housing and communities, health and social care, planning infrastructure, treasury and education. It requires effective cross-departmental working and support to achieve the larger beneficial outcomes that could be delivered.

    There needs to be ongoing cross government and cross political support and long-term stable planning, protected to some extent from short-term party-political goals. The changes needed will take many years to achieve over successive governments, and short-term changes in political direction would be a risk to the sector achieving step changes in beneficial strategic outcomes.

    For effective drinking water quality regulation, it is essential to have nationally aligned legislation for consumer equity and confidence. As the technical experts it is appropriate that the Inspectorate provides the necessary evidence-base to recommend legislative updates and this is a role that should be continued and where appropriate strengthened.

    The Inspectorate publishes long term planning guidance for water companies, which forms the basis of the water company investment programme for drinking water. This covers key national interests of water quality, cyber security and security and emergency direction. Planning frameworks are frequently multi-AMP which, assists with affordability, capacity to deliver, time to research and investigate solutions, promote innovation.

    Online safety legislation and regulation could consider drinking water misinformation as a public health risk.

    The Inspectorate is working with Defra to identify legislative changes including to its duties and powers, to assist with drinking water regulation.

    • Secondary legislation around sufficiency and resilience of supplies. The Inspectorate has a duty for sufficiency as defined in the Act but no associated powers to enforce such a duty in the Regulations;
    • Revised standards for drinking water quality, including establishing mechanisms to ensure the timely update to legislation in the future
    • Ensuring all aspects of water supply systems are within scope of the Regulations. Currently, the regulation of third parties and contractors are outside of the regulatory reach of the Inspectorate posing a huge risk to drinking water quality;
    • Understanding the role and scope for water reuse and recycling as part of overall water resource planning and management. This includes associated risks to drinking water quality and establishing regulatory safeguards to protect against such risks;
    • Including the Inspectorate as a Statutory Consultee on the requirements for infrastructure planning;
    • The governance and regulation of private water supplies;
    • Risks exposed by domestic pipework, which are the responsibility of the property owner. These could be addressed by domestic risk assessments, supply pipe ownership, a review of the Water Fittings Regulations, and conveyancing legislation regarding risks from lead pipes.

    There is some overlap between the remit of the three main water regulators, with scope for a more integrated approach on overlapping topics such as resilience of supplies and abstraction protection.

    Artificial fluoridation of supplies for dental health is expanding across the northeast. The Inspectorate owns the technical guidance on fluoridation but has no regulatory powers for ensuring compliance with the code of practice, or the administration of the correct and safe fluoride dose, other than ensuring compliance with the drinking water standard.

    The Inspectorate currently has no statutory consultee role in several important frameworks:

    • Strategic position statement
    • Defra Plan for Water
    • Water resource management plans
    • River basin management plans (although we are a statutory consultee on the EA WISER guidance)

    In future iterations of the above planning frameworks, it would be beneficial to the Inspectorate, as a formal part of the consultation process, to allow specific consideration of the potential interactions with drinking water provision and quality considerations.

    Property conveyancing reports should have a legal requirement include information on the water supply, quality and sufficiency if a private supply, presence of domestic lead plumbing.

    The water sector requires some form of strategic planning oversight that can assess the information, evidence and at times conflicting strategic priorities towards making informed high level policy decisions. This must include taking the responsibility for the necessary but difficult trade-offs, to provide more coherent and aligned planning objectives.  

    The Environmental Principles Statement was a positive policy step. However, the polluter pays principle is hard to enact in practice and insufficient emphasis has been applied to make it operate in a better way. Water companies and their consumers currently pay for cleaning up and these costs are passed on to bill payers. Developing a robust mechanism to bring the polluter pays principle into practice is urgently needed for a more effective and equitable approach.

    Management of the water environment

    Better protection of abstractions and more robust use of drinking water protected areas and safeguard zones would provide stronger protection from pollutants such as pesticides, nitrates and PFAS. Prevention is preferable to treatment – more cost effective, resilient and safer.

    Measuring and assessing the water environment

    The Inspectorate considers good reporting can be used as a very effective means of communicating complex and interconnected issues to both the industry, consumers and wider stakeholders. In reporting it is essential that recipients are not overwhelmed by the complexity

    The Inspectorate publishes the annual Chief Inspector’s Reports for both England and Wales, these reports cover public supplies and also a separate report private water supplies. The public supplies reports contain summary statistics and performance indices for all water companies with explanation and commentary. 

    The Inspectorate also publishes quarterly reports and a triennial report on drinking water quality, for the public. These documents contain a huge amount of information, and the Inspectorate is always interested in feedback and ways to make the data more accessible and understandable.

    The Inspectorate also produce consumer leaflets on various topics and our research outputs, together with water company improvement programmes.

    Water UK publish summary data on the discover water website.

    Strategic direction for the water industry

    The strategic direction set for drinking water quality by the Inspectorate follows closely the best international practices, through World Health Organization (WHO) guidelines and recommendations, and the UK is one of only a few countries to achieve 100 % in the Yale environmental index with no burden associated with drinking water (2024 Environmental Performance Index – Unsafe drinking water). 

    The Inspectorate is an appointed collaborating center with the WHO and we share expertise through the international WHO regulator network (Regnet) and the European network of regulators (ENDWARE). As the competent authority for drinking water in England and Wales, the Inspectorate has the technical skills and capability to develop long term strategies for drinking water, in consultation or partnership with government and other stakeholders. 

    The issues facing drinking water supplies are long term and complex, and do not lend themselves readily to short term solutions, examples being sufficiency, lead pipes and climate change resilience. Investment in the water industry requires a much more systemic approach to deal effectively with underlying issues, and a longer time period to develop the best approaches and deliver beneficial results.

    The Inspectorate publishes long term planning guidance for water companies, which sets out the expectations for drinking water, cyber security and physical security outcomes.

    A greater focus on long-term thinking to address long-term risks and support large infrastructure projects is needed as many schemes take several AMP investment cycles to deliver outcomes.

    Examples of multi-AMP schemes are the companies’ acceptability of drinking water undertakings for mains rehabilitation programmes to reduce discoloured water.  A multi-AMP approach allows companies to project manage the work effectively, source the necessary skills and materials internally or through contractors and deliver the programme in the most efficient and cost-effective manner e.g. street by street, rather than inefficiently targeting sites which may become an imminent priority for regulatory compliance.

    Section 3: The Regulators

    The Inspectorate takes a highly collaborative approach, with regular liaison with Ofwat and the Environment Agency, and  to a lesser extent with Natural Resources Wales.  There is good communication and exchange of information on company performance, the price review process, emerging environmental threats, specific high-profile topics, and communications.

    The three regulators have different priorities and there are some tensions around regulator specific objectives in the context of other overlapping issues managed by the other regulators. When handled and approached in a supportive and collective manner this can produce improved results. 

    The Inspectorate and Ofwat worked together constructively to enable the funding of PFAS strategies in PR24.

    Section 4: Economic regulation

    The water company’s primary duty is to supply high quality drinking water and to provide sanitation, therefore any investment process must be able to deliver adequate infrastructure resilience to meet these two aims.

    There is no statutory requirement for sustainable asset replacement and health in England, although this is somewhat covered by the Future Generations Act in Wales. With appropriate checks and balances the price review process should be able to deliver these outcomes.

    The strategic position statement has been unsuccessful due to the perceived cost of lead pipe replacement.

    The Inspectorate publishes long term planning guidance for water companies, which sets out the expectations for drinking water outcomes.

    A greater focus on long-term thinking to support long-term risks and large infrastructure projects is needed as many schemes take several investment cycles to deliver outcomes. Examples of multi-AMP schemes are the companies’ acceptability of drinking water undertakings for mains rehabilitation programmes to reduce discoloured water.

    A multi-AMP approach allows companies to project manage the work effectively, source the necessary skills and materials internally or through contractors and deliver the programme in the most efficient and cost-effective manner e.g. street by street, rather than inefficiently targeting sites which may become the priority for regulatory compliance.

    A more flexible and responsive funding framework would be beneficial on occasions, where there are fast-changing issues (e.g. cybersecurity – NIS is an area where the threat landscape is quickly changing and evolving and new guidance and/or legislation can quickly emerge to combat threats to national infrastructure, requiring service operators to invest and act promptly) or other quickly emerging risks which could materialize mid-AMP in relation to the toxicity of pollutants that enter the water environment with associated risks to abstractions for drinking water.

    Insufficient infrastructure maintenance and poor asset health is one of the key risks to safe drinking water provision. The Inspectorate’s audit programmes frequently detect instances of poor asset health. The Inspectorate has very limited powers to prevent deterioration, and only where linked to an identified and reported risk of regulatory failure.

    Drinking water schemes are required to have a statutory driver, to ensure they receive funding. This is usually a new parameter (an example being PFAS), a new statutory standard, or a risk of deterioration in quality – which must be clearly evidenced. This limited scope leads to a very restricted range of schemes being put forward for consideration. Enlarging the scope to include proactive maintenance and resilience schemes might be beneficial, and tracking the company scheme delivery across all schemes would ensure the money allocated is spent on the right issue. A lack of financial tracking has led to money being diverted into other solutions which are not as appropriate, or indeed even linked.

    Every drinking water scheme is encapsulated into a legal notice, and forms part of the Inspectorate’s normal scheme delivery assessment process.

    At PR24, Ofwat linked all drinking water quality, SEMD and NIS improvement schemes to Inspectorate legal instruments or acknowledged actions. This ensures that the technical regulator not only assesses the need and agreed with the justification but then monitors the progress through to benefits delivery.

    The Inspectorate has worked closely with Ofwat through our regular liaison meetings to align drinking water outcomes with financial incentives where possible.

    This has been achieved in the case of the Compliance Risk Index (CRI) which is linked to financial penalties and incentives, with a deadband based on median company performance, so company performance is benchmarked against industry performance, and poorer performing outliers are penalised.

    Metrics about consumer contacts (complaints) for discoloured water are also aligned with Inspectorate agreed performance indicators.

    The Inspectorate encourages the alignment of regulatory focus to drive improvements for the benefit of consumers but is careful to avoid double regulation. The Inspectorate works to develop suitable Memoranda of Understanding (MOUs) with other sector regulators to clarify roles and to avoid a ‘double’ regulatory burden on companies that is both unnecessary and inefficient.

    Customer bills

    Companies set bills depending on the amount of investment required to provide wholesome and continuous water supplies and wastewater services.

    Ideally consumers would value drinking water and accept that there is a cost and that its very good value for money, compared with bottled water or filters for example.

    Any changes should be mindful of increasing consumer confidence in drinking water quality and encouraging consumers to value and conserve water.

    The Inspectorate supports water metering of water as part of an overall demand management strategy.

    Currently abstractions below a certain volume do not require a license. We consider that all abstractions should preferably be licensed in future.

    There is a need to tackle illegal water connections which would address unfair access and use of water.

    Customer protections

    The Inspectorate frequently carries out customer call center audits and additionally investigates consumer complaints against the water company relating to drinking water quality. There is an opportunity for closer integration of consumer contacts and experience measures to better inform the landscape of company performance and to better target improvements.

    Bottled water stations used by companies to provide consumers with water during an event are a less preferred method of emergency water provisions than infusion into or re-zoning of the water supply network. Improved connectivity and network resilience could therefore improve the customer experience during events.

    Water companies maintain lists of vulnerable consumers, who require additional support during emergencies. Vulnerabilities can change over time, and therefore such lists need to be maintained. Different organisations use different definitions of vulnerability, which can cause issues when combining lists. It should be clear for companies who should be supported, and how best to support these consumers.

    Financial resilience

    Competition

    Competition must be managed so as not to hamper the ability to effectively regulate and potentially create an adverse impact on consumers.

    Drinking Water Safety Plans (DWSPs) require risk identification and risk management through all stages from catchment to consumer tap. Where different parties are responsible for different stages, the risks can be held by non-licensees; and this aspect does not fit the current regulatory model and introduces complexity and potential accountability issues.

    Where a CAP or similar under a DPC or comparable third-party arrangement is involved as part of the DWSP process this cannot currently be adequately addressed through contract law to retain the accountability. Careful arrangements are needed to ensure accountability and communication of risks to downstream parties.

    Section 5: Water Industry Public Policy Outcomes

    Protecting the environment

    Greater emphasis on catchment protection for drinking water sources would naturally over time lead to less drinking water treatment. This not only provides benefits in reduced use of consumables, energy use, carbon footprint concerns and overall treatment costs but also reduces industry reliance on supply chains where certain elements of treatment chemicals may need to be imported.

    A good example of catchment protection is the use of nitrate vulnerable zones to protect aquifers from nitrate pollution, thereby reducing the need for nitrate removal plants, or limiting the time they are needed to operate into the future.

    Delivering clean drinking water

    The drinking water regulatory system has been very effective in safeguarding consumers and providing high quality drinking water. It has incorporated the WHO water safety planning risk assessment process, whereby risks are identified and mitigated before any impact on consumers, leading to a robust system with no disease burden associated with public supplies.

    There is no secondary legislation to safeguard sufficiency and resilience. This impacts consumers with supply interruptions occurring both during events, extreme weather and high demand. The Inspectorate is working with Defra to develop resilience standards and to improve the regulation for security and emergencies, including cyber security, that will accelerate developing a more resilient supply system, and we strongly support new secondary legislation to strengthen this area of risk.

    The Chief Inspector has a duty under the Water Industry Act section 86(2) to provide recommendations on legislative updates. The Inspectorate is working with Defra to implement the output from the independent advisory group.

    Regulation 31 controls the quality of products and chemicals (substances) in contact with drinking water to prevent contamination of public supplies and is an essential health protective measure. The Inspectorate supports the expansion of accredited laboratory capacity within the UK industry and strongly recommends the UK Government takes action to ensure reliable testing provision is made available and retained either as part of statutory obligations on the water industry or via a government supported laboratory service.

    Other areas for review relate to include knowingly spreading misinformation and false assertions about drinking water quality online that erodes public confidence and incorporating water supply in conveyancing and planning system.

    Securing resilient water supply

    Integrated management through RAPID to address regional resource planning appears to be an effective approach for delivering large scale infrastructure projects across regions and companies, although projects are yet to be delivered. Integration with industrial and housing strategies for development are needed as water resources are not adequately represented in the current planning framework.

    The Inspectorate has a duty for sufficiency under the Water Industry Act but no secondary legislation to ensure sufficiency at the consumers tap, or powers to make companies improve resilience of supplies. Secondary legislation is urgently needed to address this, and the Inspectorate is working with academics and water companies to understand the current risks and develop resilience standards for statute.

    Building regulations cover grey water and recycled water but are not enforceable or aligned to the Water Industry Act or Water Supply (Water Quality) Regulations, which dictate that all water supplied to a premises must be drinking water quality. Reform is needed which takes into account the needs of all stakeholders including developers and consumers, and covers the regulation and maintenance of recycling schemes plus changes to legislation and standards of wholesomeness for recycled water. The Inspectorate is working towards new standards for wholesomeness to allow for different domestic uses and will work through the advisory group to make recommendations for the standards of wholesomeness needed and the regulatory framework, proportional to the risk, but health protective.

    Abstraction reform is especially pertinent for smaller abstractions, including private water supplies which are out of scope of the current requirements for licensing and can cause sufficiency issues to other supplies. Such supplies are particularly vulnerable to dry weather, and there is no mechanism to address this issue, nor to prevent new developments on private water supplies (Scotland is introducing legislation to ensure water supply is sustainable at planning). Although private supplies are outside the remit of this review, a significant proportion of the population rely on this for their sole water supply.

    Demand management through smart metering can reduce remand but must be applied equitably, so as not to unfairly impact on low-income households, who may be at risk of water or hygiene poverty. Stepped tariffs can assist, but further additional measures are likely to be needed to bring down demand further.

    Infrastructure and supply chain resilience and security

    The Inspectorate has a duty for sufficiency under the Water Industry Act but no secondary legislation to ensure sufficiency at the consumers tap, or powers to make companies improve resilience of supplies. Secondary legislation is urgently needed to address this, and the Inspectorate is working with academics and water companies to understand the current risks and baseline, and to develop resilience standards for guidance and statute.

    Secondary legislation would provide clarity for water companies, improve resilience planning, and better delivery through the price review process. Improved recording of companies’ commitments for resilience, will reduce risks from double funding and highlight where a company has not previously sought funds for a particular item.

    Insufficient infrastructure maintenance and poor asset health is one of the key risks to resilience and providing safe drinking water provision. As noted previously the Inspectorate has very limited powers to prevent deterioration, and only where linked to an identified and reported risk of regulatory failure. Therefore, the Inspectorate is unable to ensure companies replace assets ahead of asset failures and this in turn restricts our ability to regulate towards resilient infrastructure.

    Examples which would benefit from the Inspectorate having powers in respect of sufficiency will include improved water treatment facilities that can operate under extreme weather conditions for example, infrastructure networks that are resilient and capable of maintaining supplies despite external stresses and instigating measures to reduce supply chain vulnerabilities; in particular those related to chemicals that are vital for water treatment.

    The Inspectorate is the regulator for Security and Emergency Measures (Water and Sewerage Undertakers and Water Supply Licensees) Direction 2022 (SEMD).

    The ability of the Inspectorate to issue legal notices in respect of SEMD is urgently needed, so that the improvements can be tracked and enforced using the Inspectorate’s enforcement ladder. Statutory notices are a very powerful legal instrument which allow a planned approach to project delivery, which is tracked and auditable. The legal notice for water quality sets out the risk, then the measures to address the risk, including investigation, monitoring and delivery. The Inspectorate carries out assessments at milestones, delivery and demonstration of benefits, which are all legally prescribed.

    The Inspectorate is also the regulator for cybersecurity under the Network and Information Direction. The Inspectorate has an enforcement policy for NIS and can issue fines up to £17M.

    We recommend measures to ensure improved engagement with security services to support the sector in making an informed risk-based decision on security is needed, with the Inspectorate developing a consistent understanding of risk across the sector.

    We recommend measures to ensure improved funding for emerging risks or potentially consider funding companies to hold and manage risk ‘pots’ which are returned to consumers or rolled over between AMPs for rapid funding of specific items. The Inspectorate acknowledge the large asset base in the sector, and that change will necessarily take time, therefore a proactive approach is needed to identify and mitigate risks to allow for constructability cost.

    A general and underlying recognition that a lot of security products life span is not necessarily how long the item will actually last e.g. a door 50 years, but rather if it still addresses the identified risk, it should be mitigating e.g. that door might not be suitable after five years potentially due to advances in techniques to breach physical security infrastructure. Electronic security might be more affected by this, but the same principle applies.

    Improving environmental quality at source and addressing certain widespread water quality issues is likely to reduce amount and number of chemicals and treatment used in the treatment process. For example, removal of nitrate in catchments removes the need for nitrate removal treatment and lead removal policies would reduce the need for orthophosphate dosing. Many treatment processes, particularly those requiring chemical dosing relies on importing chemicals from abroad. This is not only costly and has associated environmental impacts but can be threatened by geopolitics and trade barriers outside of the industry’s control. Removing the need in the first instance is the preferred option.

    The lack of resilience in the chemical supply is a known risk to the industry and was acutely highlighted during recent events such as EU Exit, industrial action by lorry drivers, and the war in Ukraine. Additionally, there was a recent environmental pollution incident at a ferric supplier, which highlighted a lack of capacity and alternative suppliers in the supply chain. Many sites are not designed for bulk storage of chemicals. Water companies are responsible for managing their relationship with suppliers and the industry came together to manage this acute situation through a platinum incident management process, but systemic weaknesses persist.

    Previously a within sector arrangement was made to prioritise drinking water treatment above sewage treatment process for the immediate benefits to public health should the situation arise where common supply-chain resources were in limited supply. We do not know if this arrangement was formalised or continues, but we consider it an appropriate position to be retained. However, as the water cycle is interactive, extended disruption of either process would be likely to have detrimental impact on public health.

    There are skills shortages within the industry, which competes for talent against other utilities. Efforts should be continued and further developed to attract younger staff at all levels and in a wide variety of related disciplines into the industry for its future wellbeing.

    Innovation and technology

    The Inspectorate strongly supports innovation and would like to see more innovation around our key priorities to improve water quality, consumer confidence in drinking water, asset health and resilience, security and emergencies, and cyber security.

    For example, the Inspectorate promoted the green economic recovery lead replacement trials, and a large part of these trials was testing different methods of delivery and consumer engagement and sharing the results with the industry and regulators.

    The Inspectorate runs an active research programme to support policy on drinking water quality, sufficiency, security and public health. All our research is competitively appointed and reports published on the website, shared with stakeholders, including the WHO. This provides the evidence base for our regulation, and much is focused on new and emerging risks and contaminant. The Inspectorate works collaboratively with UKWIR on drinking water research, supporting innovation and contributing to project steering groups when appropriate.

    The Inspectorate is supportive of the use of advances in technology and innovation backed up by science and evidence, and accredited where applicable. However, given that treating and supplying drinking water is fundamental to public health and wellbeing it is paramount that innovations are well tested for their efficacy, robustness and present no risk to drinking water quality.

    The Inspectorate would be supportive of advancements to real time monitoring of water quality and asset security, both microbiological parameters and chemical parameters, to speed up identification and response times when something goes wrong.

    Section 6: Ownership

    Consolidation of water companies historically has led to efficiencies of scale. Recent fragmentation of the market for competition, including the introduction of NAVs, has introduced a new level of complexity.

    The water safety planning model relies on identifying risks from ‘source to tap’ and putting in place mitigation before there is any impact on consumers. Mitigation can be downstream of the risk in some cases, e.g. catchment risks identified and remediated at treatment, verified at sampling of the consumers tap.

    Fragmentation directly cuts across this framework, and therefore risk management becomes more complex. Accountability and risk ownership must be maintained in any system. The regulator must therefore be empowered to reach all third parties in the supply chain.

    Ownership (for Wales only)

    It would be very difficult to directly link/measure the not-for-profit model to the outcomes around any drinking water quality improvements. The model appears generally to work, although the company performance is not leading across all indices and the company has recently been put into transformation by the Inspectorate. A full report on drinking water performance in Wales is produced by the Inspectorate annually, as part of the Chief Inspector Reports.

    The Inspectorate does not consider that there are significant risks for consumers directly arising from the not-for-profit model, although more advantages could potentially be secured using this type of model, with potentially better outcomes for consumers.

    The main risk associated with Dŵr Cymru’s not-for-profit model is that it is the single not-for-profit entity in its regulated industry. The financial regulatory model does not consider this status to take advantage of any opportunities, nor does it seek to mitigate any risks.

    Veolia Water Projects Ltd

    Water supply arrangements

    Company Assets

    Number of treatment works

    92

    Number of service reservoirs 

    157

    Number of water supply zones

    89

    Length of mains pipe (km)

    16,800km

    Population Served

    Population Supplied

    3,797,000

    Number of local authorities

    41

    Water Supplied

    Water Supplied (l/day)

    950,608,000

    Percentage from surface sources

    40%

    Percentage of ground sources

    55%

    Percentage from mixed sources

    5%

    Area of supply

    Tidworth 

    Consumer Contacts

    Informing Consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    961

    0.25

    2020

    897

    0.24

    2021

    900

    0.24

    Industry Average

    2021

    9,913.96

    1.22

    Acceptability of water to consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    3,066

    0.81

    2020

    3,319

    0.88

    2021

    3,036

    0.80

    Industry Average

    2021

    2,832.12

    1.08

    Complaints to the Drinking Water Inspectorate

    No consumers of Veolia Water Projects Ltd directly contacted DWI in 2021.

    Wessex Water Services Ltd 

    Water supply arrangements

    Company Assets

    Number of treatment works

    92

    Number of service reservoirs 

    157

    Number of water supply zones

    89

    Length of mains pipe (km)

    16,800km

    Population Served

    Population Supplied

    3,797,000

    Number of local authorities

    41

    Water Supplied

    Water Supplied (l/day)

    950,608,000

    Percentage from surface sources

    40%

    Percentage of ground sources

    55%

    Percentage from mixed sources

    5%

    Area of supply

    Somerset, Dorset, Wiltshire, Gloucestershire and Devon

    Consumer Contacts

    Informing Consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    961

    0.25

    2020

    897

    0.24

    2021

    900

    0.24

    Industry Average

    2021

    9,913.96

    1.22

    Acceptability of water to consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    3,066

    0.81

    2020

    3,319

    0.88

    2021

    3,036

    0.80

    Industry Average

    2021

    2,832.12

    1.08

    Complaints to the Drinking Water Inspectorate

    No consumers of Wessex Water Services Ltd directly contacted DWI in 2021.

    Yorkshire Water Services Ltd 

    Water supply arrangements

    Company Assets

    Number of treatment works

    92

    Number of service reservoirs 

    157

    Number of water supply zones

    89

    Length of mains pipe (km)

    16,800km

    Population Served

    Population Supplied

    3,797,000

    Number of local authorities

    41

    Water Supplied

    Water Supplied (l/day)

    950,608,000

    Percentage from surface sources

    40%

    Percentage of ground sources

    55%

    Percentage from mixed sources

    5%

    Area of supply

    Barnsley, Bradford, Calderdale, Doncaster, East Riding of Yorkshire, Kingston upon Hull, City of, Kirklees, Leeds, North Lincolnshire, North Yorkshire, Nottinghamshire, Rotherham, Sheffield, Wakefield, York 

    Consumer Contacts

    Informing Consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    961

    0.25

    2020

    897

    0.24

    2021

    900

    0.24

    Industry Average

    2021

    9,913.96

    1.22

    Acceptability of water to consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    3,066

    0.81

    2020

    3,319

    0.88

    2021

    3,036

    0.80

    Industry Average

    2021

    2,832.12

    1.08

    Complaints to the Drinking Water Inspectorate

    A total of 5 consumers of Yorkshire Water Services Ltd directly contacted DWI in 2021.

    Temp

    Company name

    Sample Results

    Company statistics and company performance data

    Affinity Water

    Download (PDF 108KB)

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    TCP or medicinal taste and odour

    TCP or medicinal type tastes can be caused by a number of sources within the home. Chlorine is the most common form of disinfection across water companies. Chemical reactions between chlorine and certain fixtures and fittings can result in phenolic chemical compounds being created. In extremely low levels these compounds are not considered harmful but can lead to noticeable tastes and odours of TCP (antiseptic) or medicinal. If you notice a particularly bad or strong smell or taste which means you cannot drink the water, or you notice a smell or taste for the first time you should contact your water company immediately.

    What could be causing the taste and odour?

    Kettles

    If the taste or odour is only present in hot drinks or boiled water and is not noticeable in freshly drawn cold water from the kitchen tap this could indicate the problem lies within your kettle. To confirm this try boiling some water in a saucepan instead. If there is no smell or taste the kettle is the likely cause. Kettles contain rubber seals and other plastic parts which may be reacting with chlorine. The issue is more common in new plastic kettles and the problem may go away over time, as you use the kettle. Always follow manufacturer’s instructions when using a new kettle for the first time.

    Appliances (such as washing machines or dishwashers)

    Most modern dishwashers and washing machines are connected directly to the incoming mains water supply but are sometimes not installed correctly. All connections should include a non-return valve so that water standing in the hoses does not get drawn back into your drinking water. If the appliance does not have a non-return valve it is possible to get a rubber, plastic, disinfectant or TCP taste and odour in your tap water. To test if an appliance is the problem turn off the water to the individual appliance using the service valve. Run the tap for a while and if the taste and odour are no longer present this indicates the source of the problem was the appliance.

    Other fittings

    It is also possible that your tap washer or some part of the tap is the cause, especially if you have recently installed new taps. If you’re getting an unusual taste or smell from your kitchen tap, try using another tap in the house, such as the bathroom sink, to see if the different taste or smell is also present there. Alternatively run the original tap for a few minutes before tasting the water again. This may clear the problem through flushing. If the taste or smell persists then it could be caused by a washer or fitting in the stop tap.

    Privacy Policy

    Privacy Policy

    PRIVATE WATER SUPPLIES – CASE STUDY 2016/01

    Change of status of a Regulation 8 supply

    In October 2012 the Inspectorate received a contact from a consumer complaining of particulates in their drinking water. The Inspectorate’s investigation revealed that this consumer was receiving their supply of water from a public distribution system via a storage reservoir sited on a neighbour’s property which served both the consumer and their neighbour. This arrangement constituted a Regulation 8 supply under the Private Water Supplies Regulations 2009 as water arising from a water company was being distributed by the neighbour, who was a customer of the water company, through their reservoir to the consumer who was not a customer of the water company.

    It was found that the complainant’s water quality problem was the result of sediment disturbance in the reservoir. This occurred each time the neighbour turned off the pumps, which were located on his land and used to fill the reservoir. A long-standing dispute existed between the two neighbours originating over billing and maintenance costs and although both consumers had access to the pump under the terms of a covenant agreement, the complainant refused access on the grounds of trespassing, unless he first obtained written permission from his neighbour. Furthermore he was advised by the local water company that if he was granted permission to fill the reservoir for his own purposes by this action, that by default he would become a bill paying customer and be responsible for the reservoir remediation costs and those of upgrading the pump house. Consequently he refused to do so.

    In December 2012, the water company carried out a water fittings inspection on this supply as part of the ongoing water quality investigation, under The Water Fittings Regulations 1999. This revealed contraventions associated with the storage reservoir, which presented water quality hazards from ingress. Remediation work to mitigate this risk was required of the owner by February 2013.

    The local authority recognised this arrangement as a private water supply under Regulation 8 of the Private Water Supplies Regulations 2009. These Regulations bestow powers on the local authority to enforce on a relevant person under Section 80 of the Water Industry Act 1991 if the water is unwholesome or insufficient, and under Regulation 18 if the water presents a danger to human health. Unfortunately the local authority did not act in accordance with these requirements in a timely manner and between that time and February 2013 the owner of the primary premises disconnected his supply pipe from the water company’s communication pipe in preference to repairing the reservoir. As a consequence of this the water supply arrangements ceased to constitute a Regulation 8 supply or a public supply and both the local authority and the water company were then unable to enforce under the respective regulations for which they are responsible, to bring about the necessary remediation of the reservoir.

    The owner of the primary premises then set about establishing alternative water supply arrangements for his own property, allegedly using a redundant rainwater collection system, and gave the keys to and permission for, his neighbour to access the pumping system, should he wish to reconnect to the supply. However, the neighbour returned the keys, refusing to step onto his neighbour’s land and instead sought assistance from the local water company to make a direct connection to the public main at the required pressure to maintain sufficiency. The costs associated with this were, however, very expensive due to the topography of the land, and were beyond his means. He remained therefore without a supply of drinking water, other than bottled water, and water for other sanitary purposes from a relative living in the near vicinity into 2014.

    During this time the local authority sought further legal advice regarding their position and concluded they had no further responsibility for the case. The water company felt that they had done all that they could and had no further obligation to pursue the matter. This left only the Inspectorate to lobby for a solution as a duty of care.

    In the summer of 2014, the Chief Inspector engaged with the water company at a senior level to ask them to step in and further investigate other options to remediate the situation. The Inspectorate acknowledges and welcomes that the company responded accordingly without any regulatory obligation to do so. In September 2014, the company put forward a feasible compromise proposal to bring about a solution, which was subject to agreements and the funding by both parties. This entailed installing a new water supply from a powered pump, removing the need for the water reservoir and land access to operate the pump except for essential maintenance purposes. Once a new water supply was installed a new billing arrangement would be set up so that both parties paid for their water usage directly to the company without being incumbent on each other.

    Unfortunately an agreement to accept this arrangement could not be reached by both parties due to ongoing conflicts of interest and eventually in 2015 the owner of the secondary parcel of land sold the premises to a developer who has since renovated the property.

    A service pipe (common supply pipe) has since been installed to the boundary of the primary premise, from where the pipe divides to supply both properties on each privately owned premises. Each property will have its own meter.

    This case study demonstrates how water supply arrangements between neighbours sharing water within the context of Regulation 8 can lead to disputes, resulting in public health risks and compromising situations that are difficult to resolve. In this scenario the unhelpful response of an individual acting under these circumstances led to the unusual position where those empowered under the Water Industry Act 1991 to bring about the necessary remedial actions on a failing supply through enforcement were unable to do so. Nevertheless this very protracted and concerning unsanitary situation was avoidable if the local authority had acted in a timely manner to issue an appropriate Notice when the risk of insufficiency was known.

    This case study also highlights the varying nature of private water supply arrangements, particularly those of Regulation 8 supplies. This illustrates that while the Inspectorate has developed guidance for local authorities providing basic criteria to determine where Regulation 8 applies, realistically, circumstances will vary and may involve factors that complicate remediation of identified risks in a timely manner. This particular case study is an example of where the Inspectorate has used its discretion as an independent advisory body for private water supplies to bring about.

    PRIVATE WATER SUPPLIES – CASE STUDY 2013/11

    Regulation 8 supplies: out of sight out of mind?

    This case study concerns the unintentional identification of a Regulation 8 private water supply to 25 properties through the compliance monitoring programme of a water company. On detecting coliforms in a random sample, the company took further samples from the same property and a neighbouring one upstream. Both of these additional samples contained coliforms, so the company investigated further and found that these and other properties were connected to the water supply via a water storage tank that was in a poor hygienic condition with inadequate seals as evidenced by slugs and snails on the roof and walls of the tank, and no overflow insect guard.

    Jointly the water company and local authority issued a boil water notice and bottled water was provided until the owners had cleaned the tank and dealt with the ingress points. The local authority wrote to all the householders, but did not serve a Regulation 18 Notice. This decision, based on the fact that a risk assessment had yet to be done and further satisfactory results had been obtained, meant that the owner of the supply was not compelled to complete the remedial work in a reasonable time period. As a consequence the boil water notice remained in place for longer than three months and the management company responsible for the tank was able to defer a decision on a suitable solution to secure the long-term security of the supply (renovation or replacement).

    This case demonstrates the lack of historic local authority or water company records about situations where third parties are further distributing water (Regulation 8). Such arrangements pose a high risk because they usually involve a storage structure that is poorly designed or maintained and it is inevitable, therefore, that at some stage water in the tank will become contaminated unbeknown to those using the water for domestic purposes. Joint working to raise the awareness of property management and letting companies of the need to report such water supply arrangements to the water company and the local authority is recommended by the Inspectorate as a way of reducing the risk and avoiding costly incident investigations and remedies.

    This case also highlights how informal action by the local authority is frequently ineffective in achieving a timely or permanent remedy. As indicated in an earlier case study it is not acceptable for consumers to be expected to have to boil water for anything other than a short period of time. A Regulation 18 Notice requiring both short-term and long-term remediation with target dates would have gone a long way towards reassuring consumers, and minimising the inconvenience to them by focusing the minds of the relevant persons.

    Catchment hazards

    Contamination from a variety of activities or places can occur at any point throughout a water supply system if it is not adequately protected, managed and/or maintained. This document provides some of the key measures that can be undertaken to prevent and remediate the main forms of contamination that pose a risk to a private water supply.

    Catchment risks

    Microbiological contamination

    Microbiological contamination from faecal material can lead to illness. The following is a list of examples of actions that will assist in preventing contamination of the source:

    • Employ regular inspection and maintenance of septic tanks, at a frequency that is in accordance with the manufacturer’s instructions.
    • Installation of stock proof fencing to protect the water source from grazing animals, including rabbits and deer as well as domestic livestock.
    • Prevent storage and/or the spreading of manure within 50 metres of the water source.
    • Restrict the access of livestock from the vicinity of the source. This may be up to 50m depending on ground conditions, topography, presence of swallow holes etc.
    • Eliminate or relocate storm water overflows away from the water source;
    • Construct embankments, walls or ditches to prevent surface water entering spring collection chambers or borehole headworks.
    • Raise the well head or borehole head-works to at least 0.5 metres above ground level to prevent surface water or spillages of contaminated material entering into the water source.
    • Construct storage lagoons or tanks for untreated source water to allow settlement of sediment and organic matter ahead of any treatment.
    • Design tanks, storage chambers and borehole head works to prevent access from all animals, including rodents, invertebrates etc. This document contains more specific advice about borehole design and protection.
    • Cover and backfill or seal any abandoned boreholes or wells to prevent surface water contamination of the aquifer.
    • Limit or control recreational use of the source water near the intake point (surface water supplies).
    • Locate surface water intakes where they are least exposed to possible contamination from up-stream activities, such as surface water run-off, effluent discharge points, or other polluting activities.
    • For rainwater harvesting systems, remove or avoid the use of roof-mounted aerials or overhanging trees in the water collection area. Birds should be discouraged from perching on roof collection areas as droppings will contain bacteria. Also consider installing mechanisms to divert the first flush of rainwater to a waste system. Approved materials (e.g. WRAS or permitted under Regulation 5) should be used to prevent the contamination of rainwater during runoff and collection.

    Chemical contamination

    Some chemical contamination can lead potentially to illness or other long term health effects. Some of the following improvements at the water source will assist in preventing them from entering the water supply:

    • Establish with the environmental regulator whether any discharges from licensed facilities, such as industrial premises exist in the catchment area.
    • Limit or control recreational use of the source water to prevent contamination e.g. boat fuel spillages.
    • Limit or control the use of pesticides, herbicides and fertilisers within the catchment.
    • Construct facilities (e.g. bankside storage) to enable intakes to be closed if surface water is contaminated.
    • Create a run to waste facility for borehole or spring chambers to prevent contaminated water (e.g. after pesticide or fertiliser spraying) entering into supply. NB. Any discharges to waste may need to be agreed with the environmental regulator.
    • Locate surface water intakes where they are least exposed to possible contamination from up-stream activities, such as surface water run-off, effluent discharge points, or other polluting activities.
    • All stored fuels or oils within a 50m radius of the source should be adequately bunded to prevent leaks from contaminating the supply.

    Surface water with chemical film

    Physical contamination

    Contamination by physical particles can lead to the water becoming unacceptable in appearance, taste or odour, and may act as a substrate for micro-organisms to live on and replicate. Some of the following improvements at the source can be effective in preventing them from entering the water supply:

    • Install screens or filters for rainwater harvesting systems; protection of inlets and the setting up of a cleaning regime for any collection gutters will help prevent/reduce ingress of organic matter into the system.
    • Construct storage lagoons or tanks for raw surface? water to allow settlement to occur.
    • Regularly maintain treatment equipment e.g. cartridge filters need to be cleaned or replaced according to manufacturer’s instructions.
    • Install screens and covers on storage tanks to prevent ingress of particles, insects and other small animals etc.
    • Regularly carry out visual checks, inspections and cleaning of storage tanks at suitable intervals to reduce sludge or sediment build-up.
    • Consider using valves and/or level sensors to help prevent stagnation of water and ensure water turnover occurs.

    Tank with murky (turbid) water

    BRL (Bristol Water Plc)

    Report Data Range: For the whole year 2021

    Table 1: Quality of water leaving service treatment works – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    Nitrite (Total)

    A013B

    0.1 mg NO2/l

    122

    0

    <0.002

    <0.01894

    0

    Totals

    122

    0

    Table 2: Quality of water leaving service treatment works – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    3,371

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    3,371

    5

    0

    0

    4

    Totals

    6,742

    5

    Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    3,371

    N/A

    0

    5

    Residual Disinfectant – Free

    C009

    No abnormal change

    3,368

    N/A

    0.38

    1.73

    Residual Disinfectant – Total

    C010

    No abnormal change

    3,368

    N/A

    0.45

    1.79

    Turbidity – Indicator

    A002A

    1 NTU

    3,371

    1

    <0.13

    0.37

    Totals

    13,478

    1

    Table 4: Quality of water leaving service reservoirs – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of reservoirs failing standard

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    7,941

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    7,941

    3

    0

    0

    0

    Totals:

    15,882

    3

    Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    7,941

    N/A

    0

    208

    Residual Disinfectant – Free

    C009

    No abnormal change

    7,936

    N/A

    <0.05

    0.75

    Residual Disinfectant – Total

    C010

    No abnormal change

    7,936

    N/A

    0.14

    0.84

    Totals:

    23,813

    0

    Table 6: Quality of water leaving bulk supply points – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply point with failures

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    123

    0

    <0.16

    <0.16

    0

    Benzene (Total)

    F002

    1 µg/l

    122

    0

    <0.06

    <0.09

    0

    Boron

    D005A

    1 mg B/l

    123

    0

    0.016668

    0.15252

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    119

    0

    <1.2

    <5.5

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    124

    0

    0.05

    0.42

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    120

    0

    <0.04

    <0.06

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    123

    0

    0

    0.0188

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    29

    0

    <0.012

    <0.012

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    7

    0

    <0.004

    0.015

    0

    Pesticides Azoxystrobin

    P227

    0.1 µg/l

    7

    0

    <0.007

    0.008

    0

    Pesticides Bixafen

    P279

    0.1 µg/l

    26

    0

    <0.004

    <0.014

    0

    Pesticides Boscalid

    P231

    0.1 µg/l

    15

    0

    <0.009

    <0.011

    0

    Pesticides Bromoxynil

    P008

    0.1 µg/l

    8

    0

    <0.009

    <0.009

    0

    Pesticides Carbetamide 

    P010

    0.1 µg/l

    29

    0

    <0.008

    <0.01

    0

    Pesticides Chlormequat

    P163

    0.1 µg/l

    7

    0

    <0.003

    <0.003

    0

    Pesticides Chlorothalonil

    P015

    0.1 µg/l

    7

    0

    <0.006

    <0.014

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    68

    0

    <0.011

    0.02

    0

    Pesticides Cyproconazole

    P207

    0.1 µg/l

    15

    0

    <0.007

    <0.008

    0

    Pesticides Deltamethrin

    P095

    0.1 µg/l

    16

    0

    <0.005

    <0.009

    0

    Pesticides Desthioprothioconazole

    P237

    0.1 µg/l

    15

    0

    <0.005

    <0.007

    0

    Pesticides Diflufenican

    P157

    0.1 µg/l

    7

    0

    <0.007

    <0.009

    0

    Pesticides Epoxyconazole

    P217

    0.1 µg/l

    7

    0

    <0.005

    <0.006

    0

    Pesticides Flufenacet

    P230

    0.1 µg/l

    36

    0

    <0.008

    <0.009

    0

    Pesticides Fluroxypyr

    P040

    0.1 µg/l

    36

    0

    <0.009

    <0.012

    0

    Pesticides Fluxapyroxad

    P274

    0.1 µg/l

    37

    0

    <0.009

    <0.011

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    82

    0

    <0.005

    <0.02

    0

    Pesticides Lambda-Cyhalothrin

    P216

    0.1 µg/l

    26

    0

    <0.006

    <0.006

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    36

    0

    <0.008

    <0.012

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    36

    0

    <0.007

    0.009

    0

    Pesticides Mepiquat

    P165

    0.1 µg/l

    42

    0

    <0.004

    <0.004

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    95

    0

    <0.007

    0.013

    0

    Pesticides Metazachlor

    P203

    0.1 µg/l 

    29

    0

    <0.006

    <0.007

    0

    Pesticides Metconazole

    P281

    0.1 µg/l

    7

    0

    <0.005

    <0.005

    0

    Pesticides Metsulfuron

    P210

    0.1 µg/l

    26

    0

    <0.004

    <0.026

    0

    Pesticides Pendimethalin

    P118

    0.1 µg/l

    7

    0

    <0.009

    <0.02

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    29

    0

    <0.007

    <0.009

    0

    Pesticides Prosulfocarb

    P243

    0.1 µg/l

    36

    0

    <0.007

    <0.009

    0

    Pesticides Quinmerac

    P224

    0.1 µg/l

    29

    0

    <0.006

    <0.007

    Pesticides Tebuconazole

    P177

    0.1 µg/l

    36

    0

    <0.005

    <0.009

    0

    Pesticides Thifensulfuron-methyl

    P260

    0.1 µg/l

    20

    0

    <0.006

    0.011

    0

    Pesticides Tri-allate

    P079

    0.1 µg/l

    26

    0

    <0.005

    <0.006

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    36

    0

    <0.015

    <0.028

    0

    Pesticides Trinexapac-ethyl

    P236

    0.1 µg/l

    26

    0

    <0.011

    <0.012

    0

    Radon

    F031

    100 Bq/l

    5

    0

    3.4

    5.61

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    122

    0

    0.71

    0.85

    0

    Totals

    1,977

    0

    Table 7: Quality of water leaving bulk supply points – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply points with failures

    Tetrachloromethane (Total)

    D008

    3 µg/l

    121

    0

    <0.13

    <0.16

    0

    Totals

    121

    0

    Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Chloride

    D002A

    250 mg Cl/l

    124

    0

    12.85

    68.65

    Clostridium Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    1,227

    0

    0

    0

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    1,226

    0

    213.35

    731.46

    Gross Alpha

    F004

    0.1 Bq/l

    23

    0

    <0.022

    0.074

    Gross Beta

    F005

    1 Bq/l

    23

    0

    0.055

    0.113

    Sulphate

    A007

    250 mg SO4/l

    123

    0

    6.9664

    128.04

    Total Organic Carbon

    A017

    No abnormal change

    123

    N/A

    0.6

    3.0672

    Totals

    2,869

    0

    Table 9: Quality of water at consumer’s tap (zones) – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of zones failing standard

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    4

    0

    <0.16

    <0.16

    0

    Antimony

    B008A

    5 µg Sb/l

    215

    0

    <0.01

    0.4768

    0

    Arsenic (Total)

    B001A

    10 µg As/l

    215

    0

    0.0316

    4.4916

    0

    Benzene (Total)

    F002

    1 µg/l

    4

    0

    <0.06

    <0.06

    0

    Benzo[a]Pyrene (Total)

    D007

    0.01 µg/l

    213

    0

    <0.00057

    <0.0012604

    0

    Boron

    D005A

    1 mg B/l

    4

    0

    <0.0319

    <0.0319

    0

    Bromate

    F003

    10 µg BrO3/l

    215

    0

    <0.15

    6.056

    0

    Cadmium (Total)

    B002

    5 µg Cd/l

    215

    0

    <0.01

    0.7284

    0

    Chromium (Total)

    B004

    50 µg Cr/l

    215

    0

    <0.04

    0.5652

    0

    Copper (Total)

    A024A

    2 mg Cu/l

    215

    0

    <0.0003548

    0.46804

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    4

    0

    <1.4

    <5.5

    0

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    3,127

    0

    0

    0

    0

    Enterococci (Confirmed)

    C003

    0 number/100 ml

    215

    0

    0

    0

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    4

    0

    0.09

    0.12

    0

    Lead (10 – will apply 25.12.2013)

    B007B

    10 µg Pb/l

    212

    3

    <0.02

    17.559

    3

    Mercury (Total)

    B005

    1 µg Hg/l 

    4

    0

    <0.06

    <0.06

    0

    Nickel (Total) 

    B006A 

    20 µg Ni/l

    215

    0

    0.2

    13.168

    0

    Nitrate (Total)

    A012

    50 mg NO3/l

    214

    0

    <2.13

    31.158

    0

    Nitrite – Consumer’s Taps

    A013A

    0.5 mg NO2/l

    214

    0

    <0.002

    <0.0139

    0

    Nitrite/Nitrate formula

    A013C

    1 mg/l

    214

    0

    0.043

    0.6241

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    4

    0

    0

    0

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    4

    0

    <0.012

    <0.012

    0

    Pesticides 2 4-DB

    P082

    0.1 µg/l

    4

    0

    <0.017

    <0.018

    0

    Pesticides Alpha-HCH

    P003

    0.1 µg/l

    4

    0

    <0.005

    <0.006

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    3

    0

    <0.004

    <0.005

    0

    Pesticides Boscalid

    P231

    0.1 µg/l

    4

    0

    <0.009

    <0.011

    0

    Pesticides Carbetamide 

    P010

    0.1 µg/l

    4

    0

    <0.008

    <0.01

    0

    Pesticides Chlormequat

    P163

    0.1 µg/l

    4

    0

    <0.003

    <0.003

    0

    Pesticides Chlorpyrifos (Chlorpyriphos Ethyl)

    Po17

    0.1 µg/l

    4

    0

    <0.016

    <0.016

    0

    Pesticides Chlortoluron

    P014

    0.1 µg/l

    3

    0

    <0.006

    <0.014

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    4

    0

    <0.011

    <0.015

    0

    Pesticides Dicamba

    P025

    0.1 µg/l

    4

    0

    <0.012

    <0.014

    0

    Pesticides Diuron

    P032

    0.1 µg/l

    4

    0

    <0.009

    <0.01

    0

    Pesticides Flufenacet

    P230

    0.1 µg/l

    4

    0

    <0.008

    <0.009

    0

    Pesticides Fluroxypyr

    P040

    0.1 µg/l

    4

    0

    <0.009

    <0.012

    0

    Pesticides Flutriafol

    P039

    0.1 µg/l

    4

    0

    <0.005

    <0.005

    0

    Pesticides Gamma-HCH (Lindane)

    P041

    0.1 µg/l

    4

    0

    <0.005

    <0.006

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    4

    0

    <0.005

    <0.005

    0

    Pesticides Isoproturon

    P048

    0.1 µg/l

    3

    0

    <0.005

    <0.006

    0

    Pesticides Linuron

    P051

    0.1 µg/l

    4

    0

    <0.007

    <0.012

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    4

    0

    <0.008

    <0.012

    0

    Pesticides MCPB

    P055

    0.1 µg/l

    4

    0

    <0.018

    <0.018

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    4

    0

    <0.007

    <0.009

    0

    Pesticides Metazachlor

    P203

    0.1 µg/l 

    4

    0

    <0.006

    <0.007

    0

    Pesticides Methiocarb

    P056

    0.1 µg/l

    4

    0

    <0.007

    <0.008

    0

    Pesticides Prometryne

    p)70

    0.1 µg/l

    4

    0

    <0.004

    <0.005

    0

    Pesticides Propazine

    P066

    0.1 µg/l

    3

    0

    <0.004

    <0.007

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    4

    0

    <0.007

    <0.009

    0

    Pesticides Quinmerac

    P244

    0.1 µg/l

    4

    0

    <0.006

    <0.007

    0

    Pesticides Simazine

    P073

    0.1 µg/l

    3

    0

    <0.004

    <0.005

    0

    Pesticides Tri-allate

    P079

    0.1 µg/l

    2

    0

    <0.006

    <0.006

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    4

    0

    <0.015

    <0.028

    0

    Polycyclic Aromatic Hydrocarbons (Total by Calculation)

    B011F

    0.1 µg/l

    211

    0

    0

    0.00288

    0

    Selenium (Total)

    B009

    10 µg Se/l

    215

    0

    <0.08

    1.1636

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    4

    0

    0.85

    0.85

    0

    Trihalomethanes (Total by Calculation)

    D011

    100 µg/l

    215

    0

    0.46316

    58.1232

    0

    Totals

    6,704

    3

    Table 10: Quality of water at consumer’s tap (zones) – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    No. of zones failing standard

    Aluminium (Total)

    A021

    200 µg Al/l

    4,383

    0

    <6

    34.028

    0

    Colour

    A001

    20 mg/l Pt/Co

    4,917

    0

    <0.68

    2.3

    0

    Iron (Total)

    A022

    200 µg Fe/l

    4,383

    6

    <7

    78.16

    6

    Manganese (Total)

    A023

    50 µg Mn/l

    4,383

    0

    <3

    3.716

    0

    Odour

    A003

    0 Dilution number at 25°C

    4,920

    41

    0

    0

    32

    Sodium (Total)

    A009

    200 mg Na/l

    1,340

    0

    9.4505

    81.272

    0

    Taste (Taste Quant)

    A004

    0 Dilution number at 25°C

    4,917

    16

    0

    0

    17

    Tetrachloromethane (Total)

    D008

    3 µg/l

    51

    0

    <0.081

    <0.313

    0

    Turbidity

    A002

    4 NTU

    4,917

    0

    <0.09

    <0.313

    0

    Totals

    34,211

    63

    Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Ammonium (Total)

    A014

    0.5 mg NH4/l

    2,894

    0

    <0.14

    0.26205

    Chloride

    D002A

    250 mg Cl/l

    51

    0

    <6.83

    82

    Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    51

    0

    0

    0

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    13,123

    29

    0

    0

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    4,916

    N/A

    0

    22

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    1,912

    0

    283.39

    747.87

    Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

    A006

    6.5 – 9.5 pH Value

    3,373

    0

    6.9

    7.7

    Residual Disinfectant – Total

    C010

    No abnormal change

    9,665

    N/A

    0.09

    0.98

    Sulphate

    A007

    250 mg SO4/l

    767

    0

    <11

    118.32

    Total Organic Carbon

    A017

    No abnormal change

    675

    N/A

    <0.4

    4.1

    Totals

    34,984

    17

    South West Water Limited – Water Quality Monitoring and Control Dousland WTW

    Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

    Reference: SWB-2024-00002

    Version Number: 1

    Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): South West Water Limited, with registered number 02366665 (hereinafter called ‘the Company’).

    Assets Affected:

    • Dousland WTW T5310F

    Details of this Notice:

    1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a regulation 28(1) report of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated 21 October 2020 which states that there is or has been a significant risk of supplying water from Dousland WTW (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
    2. Consequently, this Notice is served on the Company by the Inspectorate on behalf of the Secretary of State, under regulation 28(4) for the assets listed above, for risks associated with:

    Description of Risk

    Hazard/ Hazardous Event/ Parameter

    Hazard I D

    Potential risks of inadequate disinfection or uncompliant water leaving treatment works.

    Hydrogen ion (pH) – A006

    178

    Potential risks of inadequate disinfection or uncompliant water leaving treatment works.

    Turbidity – A002

    151

    Potential risks of inadequate disinfection or uncompliant water leaving treatment works.

    E. coli – C002

    379

    Potential risks of inadequate disinfection or uncompliant water leaving treatment works.

    Total Coliforms – C001

    401

    Table 1: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.

    1. The Company are required to satisfy the following requirements.

    The date given is that until or by which the requirements must be maintained or satisfied, as appropriate.

    Requirements:

    (a) To maintain the following measures for the period specified in each case:

    1. Review the risk assessment of short-term process outages:
      • Identifying the risks and determine the mitigations required to protect water quality as a result of processes being removed and/or returned to supply.
      • Ensure such risk assessments are reviewed and kept up to date.
        Date: Ongoing for the duration of this Notice
    2. Adherence to site specific start-up and shutdown procedures.
      Date: Ongoing for the duration of this Notice
    3. Adherence to company water quality investigational sampling procedures to ensure compliance with the requirements of regulations 10, 18 and 19.
      Date: Ongoing for the duration of this Notice
    4. Operation of all processes within defined operating ranges with appropriate and documented, triggers and responses where deviations occur.
      Date: Ongoing for the duration of this Notice
    5. Maintain instrument maintenance, calibration and verification to ensure the treatment works operate to the requirements of the Site-Specific Disinfection Policy.
      Date: Ongoing for the duration of this Notice

    (b) To review, revise or make operational the following measures, by the dates specified in each case:

    1. Install and commission duplicate chlorine, duplicate turbidity, and duplicate pH instrumentation post contact tank.
      Date: 30 June 2028

    (c) To audit whether the measures have been effective by the following means:

    1. Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
      Date: 30 November 2024
    2. Implement, and keep under continuous review, the audit strategy defined in measure (c)1.
      Date: Following completion of measure (c)1. onwards.

    (d) Not to supply water for regulation 4(1) purposes from Dousland WTW, or not to so supply unless the specified conditions below are satisfied:

    1. Not applicable.

    (e) To provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risks:

    1. Provide a progress report annually.
      Date: by 31 January each year.
    2. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
      Date: 31 December 2024
    3. Provide evidence of the installation, commissioning and operation of the instruments, as specified in measure (b)1.
      Date: 31 July 2028
    4. Submit any revisions of the audit strategy produced under measure (c)2.
      Date: Within 1 month of a revision
    5. Submit a report in the event that any completed measures of this Notice need to be altered in any way, for any reason.
      Date: Ongoing for the duration of this Notice
    6. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
      Date: 30 September 2028

    Further Details of this Notice:

    1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
    2. Under regulation 28(6) the Inspectorate, on behalf of the Secretary of State, may by notice served on the Company, revoke or vary this Notice.
    3. Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991 (as amended).

    Signed

    Nicholas Adjei
    Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
    2 September 2024
    Reference: SWB-2024-00002 v1

     

    South West Water Limited – Water Quality Monitoring and Control Prewley WTW

    Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

    Reference: SWB-2024-00003

    Version Number: 1

    Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): South West Water Limited, with registered number 02366665 (hereinafter called ‘the Company’).

    Assets Affected:

    • Prewley WTW T3832F

    Details of this Notice:

    1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a regulation 28(1) report of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated 21 October 2020, which states that there is or has been a significant risk of supplying water from Prewley WTW (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
    2. Consequently, this Notice is served on the Company by the Inspectorate on behalf of the Secretary of State, under regulation 28(4) for the assets listed above, for risks associated with:

    Description of Risk


    Hazard/ Hazardous Event/ Parameter

    Hazard I D


    Potential risks of inadequate disinfection or uncompliant water leaving treatment works.

    Hydrogen ion (pH) -A006

    12539


    Potential risks of inadequate disinfection or uncompliant water leaving treatment works.

    Turbidity – A002

    12542


    Potential risks of inadequate disinfection or uncompliant water leaving treatment works.

    E. coli – C002

    12497


    Potential risks of inadequate disinfection or uncompliant water leaving treatment works.

    Total Coliforms -C001

    12175

    Table 1: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.

    1. The Company are required to satisfy the following requirements.

    The date given is that until or by which the requirements must be maintained or satisfied, as appropriate.

    Requirements:

    (a) To maintain the following measures for the period specified in each case:

    1. Review the risk assessment of short-term process outages:
      • Identifying the risks and determine the mitigations required to protect water quality as a result of processes being removed and/or returned to supply.
      • Ensure such risk assessments are reviewed and kept up to date.
        Date: Ongoing for the duration of this Notice
    2. Adherence to site specific start-up and shutdown procedures.
      Date: Ongoing for the duration of this Notice
    3. Adherence to company water quality investigational sampling procedures to ensure compliance with the requirements of regulations 10, 18 and 19.
      Date: Ongoing for the duration of this Notice
    4. Operation of all processes within defined operating ranges with appropriate and documented, triggers and responses where deviations occur.
      Date: Ongoing for the duration of this Notice
    5. Maintain instrument maintenance, calibration and verification to ensure the treatment works operate to the requirements of the Site-Specific Disinfection Policy.
      Date: Ongoing for the duration of this Notice

    (b) To review, revise or make operational the following measures, by the dates specified in each case:

    1. Install and commission duplicate chlorine, duplicate turbidity, and duplicate pH instrumentation post contact tank.
      Date: 30 June 2027

    (c) To audit whether the measures have been effective by the following means:

    1. Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
      Date: 30 November 2024
    2. Implement, and keep under continuous review, the audit strategy defined in measure (c)1.
      Date: Following completion of measure (c)1. onwards.

    (d) Not to supply water for regulation 4(1) purposes from Prewley WTW, or not to so supply unless the specified conditions below are satisfied:

    1. Not applicable.

    (e) To provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risks:

    1. Provide a progress report annually.
      Date: by 31 January each year.
    2. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
      Date: 31 December 2024
    3. Provide evidence of the installation, commissioning and operation of the instruments, as specified in measure (b)1.
      Date: 31 July 2027
    4. Submit any revisions of the audit strategy produced under measure (c)2.
      Date: Within 1 month of a revision
    5. Submit a report in the event that any completed measures of this Notice need to be altered in any way, for any reason.
      Date: Ongoing for the duration of this Notice
    6. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
      Date: 30 September 2027

    Further Details of this Notice:

    1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
    2. Under regulation 28(6) the Inspectorate, on behalf of the Secretary of State, may by notice served on the Company, revoke or vary this Notice.
    3. Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991 (as amended).

    Signed

    Nicholas Adjei
    Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
    2 September 2024
    Reference: SWB-2024-00003 v1

     

    Anglian Water Services Ltd

    Water supply arrangements

    Company Assets

    Number of treatment works

    136

    Number of service reservoirs 

    340

    Number of water supply zones

    164

    Length of mains pipe (km)

    38,062.47km

    Population Served

    Population Supplied

    4,781,000

    Number of local authorities

    59

    Water Supplied

    Water Supplied (l/day)

    1,186,150,000

    Percentage from surface sources

    43.51%

    Percentage of ground sources

    40.69%

    Percentage from mixed sources

    15.8%

    Area of supply

    Bedford, Buckinghamshire, Cambridgeshire, Central Bedfordshire, Doncaster, Essex, Hartlepool, Lincolnshire, Milton Keynes, Norfolk, North East Lincolnshire, North Lincolnshire, Northamptonshire, Nottinghamshire, Peterborough, Rutland, Suffolk

    Consumer Contacts

    Informing Consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    1380

    0.30

    2020

    1098

    0.23

    2021

    1334

    0.28

    Industry Average

    2021

    9,913.96

    1.22

    Acceptability of water to consumers

    Company Figure

    Total Number

    Rate per 1,000 population

    2019

    5,309

    1.15

    2020

    5,592

    1.18

    2021

    5,235

    1.10

    Industry Average

    2021

    2,832.12

    1.08

    Complaints to the Drinking Water Inspectorate

    A total of 3 consumers of Anglian Water Services Ltd directly contacted DWI in 2021

    Radioactivity Notice: Northumbrian Water Limited

    Notice Reference: NES-2023-00011

    Notice under regulation 6(12) of the Water Supply (Water Quality) Regulations 2016 (as amended) (“the Regulations”)

    Radioactivity Monitoring of Water Supplies

    1. Water Undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Northumbrian Water Limited, with registered number 2366703 (hereinafter called ‘the Company’).
    2. This Notice is made by the Secretary of State under the power in regulation 6(12) of the Regulations. It takes effect from 10 December 2023 and it will expire on 10 December 2028, unless otherwise withdrawn.
    3. Regulation 6(7) to (15) of the Regulations relates to the monitoring by water companies of radioactive parameters in the water supply zones they supply. Specifically, regulation 6 requires water companies to monitor parameters for indicative dose, radon and tritium.
    4. Regulation 6(12) of the Regulations provides that the Secretary of State may notify a water company that a radioactive parameter need not be monitored if they are satisfied that, for the period specified in the notice and for the purposes of regulation 4(1), the water supplied to that zone:
      • gives rise to a calculated indicative dose that is below the parametric value specified in Schedule 2 to the Regulations;
      • contains levels of radon that are below the parametric value specified in Schedule 2 to the Regulations;
      • contains levels of tritium that are below the parametric value specified in Schedule 2 to the Regulations.
    5. Based on the evidence presented by the Company, the Secretary of State, is satisfied that the water supplied to the water supply zones listed in the Schedule to the Notice (“the Schedule”) contains levels of total indicative dose, Tritium and Radon that are below the parametric values specified in the relevant part of Schedule 2 to the Regulations.
    6. Accordingly, for the period the Notice has effect, the Company need not conduct regulatory monitoring for total indicative dose , Tritium and Radon for the sites listed in the Schedule.
    7. Pursuant to regulation 6(14) of the Regulations, the Secretary of State must, by notice in writing, withdraw this Notice if they have reason to believe that water supplied to the zone in question, for regulation 4(1) purposes, gives rise to a calculated indicative dose, or contains levels of radon or tritium which are likely to exceed the parametric value specified in Schedule 2 of the Regulations.
    8. In the event that this Notice is withdrawn under regulation 6(14), the Company must monitor the relevant parameter in accordance with Tables 2 and 3 in Schedule 3 to the Regulations.

    Signed

    Marcus Rink

    Chief Inspector of Drinking Water for the Secretary of State for Environment, Food and Rural Affairs

    13 November 2023

    Ref: NES-2023-00011

    South West Water Limited – Water Quality Monitoring and Control Lowermoor WTW

    Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

    Reference: SWB-2024-00004

    Version Number: 1

    Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): South West Water Limited, with registered number 02366665 (hereinafter called ‘the Company’).

    Assets Affected:

    • Lowermoor WTW T2318F

    Details of this Notice:

    1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a regulation 28(1) report of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated 21 October 2020 which states that there is or has been a significant risk of supplying water from Lowermoor WTW (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
    2. Consequently, this Notice is served on the Company by the Inspectorate on behalf of the Secretary of State, under regulation 28(4) for the assets listed above, for risks associated with:

    Description of Risk


    Hazard/ Hazardous Event/ Parameter

    Hazard I D


    Potential risks of inadequate disinfection or uncompliant water leaving treatment works.

    Hydrogen ion (pH) -A006

    13433


    Potential risks of inadequate disinfection or uncompliant water leaving treatment works.

    Turbidity – A002

    13446


    Potential risks of inadequate disinfection or uncompliant water leaving treatment works.

    E. coli – C002

    12815


    Potential risks of inadequate disinfection or uncompliant water leaving treatment works.

    Total Coliforms -C001

    13554

    Table 1: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.

    1. The Company are required to satisfy the following requirements.

    The date given is that until or by which the requirements must be maintained or satisfied, as appropriate.

    Requirements:

    (a) To maintain the following measures for the period specified in each case:

    1. Review the risk assessment of short-term process outages:
      • Identifying the risks and determine the mitigations required to protect water quality as a result of processes being removed and/or returned to supply.
      • Ensure such risk assessments are reviewed and kept up to date.

    Date: Ongoing for the duration of this Notice

    1. Adherence to site specific start-up and shutdown procedures.
      Date: Ongoing for the duration of this Notice
    2. Adherence to company water quality investigational sampling procedures to ensure compliance with the requirements of regulations 10, 18 and 19.
      Date: Ongoing for the duration of this Notice
    3. Operation of all processes within defined operating ranges with appropriate and documented, triggers and responses where deviations occur.
      Date: Ongoing for the duration of this Notice
    4. Maintain instrument maintenance, calibration and verification to ensure the treatment works operate to the requirements of the Site-Specific Disinfection Policy.
      Date: Ongoing for the duration of this Notice

    (b) To review, revise or make operational the following measures, by the dates specified in each case:

    1. Install and commission duplicate chlorine, duplicate turbidity, and duplicate pH instrumentation post contact tank.
      Date: 31 March 2029

    (c) To audit whether the measures have been effective by the following means:

    1. Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
      Date: 30 November 2024
    2. Implement, and keep under continuous review, the audit strategy defined in measure (c)1.
      Date: Following completion of measure (c)1. onwards.

    (d) Not to supply water for regulation 4(1) purposes from Lowermoor WTW, or not to so supply unless the specified conditions below are satisfied:

    1. Not applicable.

    (e) To provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risks:

    1. Provide a progress report annually.
      Date: by 31 January each year
    2. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
      Date: 31 December 2024
    3. Provide evidence of the installation, commissioning and operation of the instruments, as specified in measure (b)1.
      Date: 30 April 2029
    4. Submit any revisions of the audit strategy produced under measure (c)2.
      Date: Within 1 month of a revision
    5. Submit a report in the event that any completed measures of this Notice need to be altered in any way, for any reason.
      Date: Ongoing for the duration of this Notice
    6. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
      Date: 30 June 2029

    Further Details of this Notice:

    1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
    2. Under regulation 28(6) the Inspectorate, on behalf of the Secretary of State, may by notice served on the Company, revoke or vary this Notice.
    3. Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991 (as amended).

    Signed

    Nicholas Adjei
    Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
    2 September 2024
    Reference: SWB-2024-00004 v1

     

    DWR (Dwr Cymru Welsh Water)

    Report Data Range: For the whole year 2021

    Table 1: Quality of water leaving service treatment works – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    Nitrite (Total)

    A013B

    0.1 mg NO2/l

    508

    0

    <0.015

    <0.015

    0

    Totals

    508

    0

    Table 2: Quality of water leaving service treatment works – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    10,947

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    10,947

    5

    0

    0

    5

    Totals

    21,894

    5

    Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    10,921

    N/A

    0

    2

    Residual Disinfectant – Free

    C009

    No abnormal change

    10,965

    N/A

    0.41

    1.22

    Residual Disinfectant – Total

    C010

    No abnormal change

    10,964

    N/A

    0.46

    1.31

    Turbidity – Indicator

    A002A

    1 NTU

    10,931

    1

    <0.3

    <0.3

    Totals

    43,781

    1

    Table 4: Quality of water leaving service reservoirs – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of reservoirs failing standard

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    16,778

    1

    0

    0

    1

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    16,778

    14

    0

    0

    0

    Totals:

    33,556

    15

    Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    16,743

    N/A

    0

    2

    Residual Disinfectant – Free

    C009

    No abnormal change

    16,810

    N/A

    0.24

    0.93

    Residual Disinfectant – Total

    C010

    No abnormal change

    16,809

    N/A

    0.32

    1

    Totals:

    50,362

    0

    Table 6: Quality of water leaving bulk supply points – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply point with failures

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    218

    0

    <0.18

    <0.18

    0

    Benzene (Total)

    F002

    1 µg/l

    220

    0

    <0.097

    <0.097

    0

    Boron

    D005A

    1 mg B/l

    213

    0

    <0.014

    <0.014

    0

    Bromate

    F003

    10 µg BrO3/l

    65

    0

    <0.46

    3.2

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    212

    0

    <3.6

    <3.6

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    214

    0

    <0.11

    <0.11

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    213

    0

    <0.037

    <0.037

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    218

    0

    0

    0.05086

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    212

    0

    <0.0078

    0.008661

    0

    Pesticides 2 4-DB

    P082

    0.1 µg/l

    8

    0

    <0.014

    <0.014

    0

    Pesticides Aldrin

    P002

    0.1 µg/l

    214

    0

    <0.0065

    <0.0065

    0

    Pesticides Asulam

    P133

    0.1 µg/l

    214

    0

    <0.011

    <0.011

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    8

    0

    <0.0079

    0.032

    0

    Pesticides Diazinon

    P024

    0.1 µg/l

    37

    0

    <0.015

    <0.015

    0

    Pesticides Dicamba

    P025

    0.1 µg/l

    8

    0

    <0.023

    <0.023

    0

    Pesticides Dieldrin

    P028

    0.03 µg/l

    214

    0

    <0.007

    <0.007

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    214

    0

    <0.0064

    <0.00776

    0

    Pesticides Heptachlor

    P043

    0.03 µg/l

    214

    0

    <0.0081

    <0.0081

    0

    Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

    P044

    0.03 µg/l

    214

    0

    <0.0057

    <0.0057

    0

    Pesticides Linuron

    P051

    0.1 µg/l

    8

    0

    <0.012

    <0.012

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    214

    0

    <0.011

    <0.011

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    213

    0

    <0.0087

    <0.0087

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    8

    0

    <0.008

    <0.008

    0

    Pesticides Metamitron

    P194

    0.1 µg/l 

    9

    0

    <0.014

    <0.014

    0

    Pesticides Propetamphos

    P069

    0.1 µg/l

    1

    0

    <0.015

    <0.015

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    8

    0

    <0.012

    <0.012

    0

    Pesticides Quinmerac

    P224

    0.1 µg/l

    8

    0

    <0.006

    <0.016

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    27

    0

    <0.012

    <0.012

    0

    Radon

    F031

    100 Bq/l

    4

    0

    0.7

    1.2

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    218

    0

    0

    0.1701

    0

    Totals

    3,848

    0

    Table 7: Quality of water leaving bulk supply points – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply points with failures

    Tetrachloromethane (Total)

    D008

    3 µg/l

    212

    0

    <0.21

    <0.21

    0

    Totals

    212

    0

    Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Chloride

    D002A

    250 mg Cl/l

    214

    0

    10.1

    29

    Clostridium Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    517

    0

    0

    0

    Sulphate

    A007

    250 mg SO4/l

    214

    0

    <8.9

    59.95

    Total Organic Carbon

    A017

    No abnormal change

    214

    N/A

    <0.57

    1.97

    Tritium

    F006

    100 Bq/l

    8

    0

    <3

    <3

    Totals

    1,167

    0

    Table 9: Quality of water at consumer’s tap (zones) – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of zones failing standard

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    448

    0

    <0.18

    <0.18

    0

    Antimony

    B008A

    5 µg Sb/l

    645

    0

    <0.083

    0.12

    0

    Arsenic (Total)

    B001A

    10 µg As/l

    645

    0

    <0.43

    0.6616

    0

    Benzene (Total)

    F002

    1 µg/l

    454

    0

    <0.097

    <0.097

    0

    Benzo[a]Pyrene (Total)

    D007

    0.01 µg/l

    649

    0

    <0.0013

    <0.0013

    0

    Boron

    D005A

    1 mg B/l

    426

    0

    <0.14

    <0.14

    0

    Bromate

    F003

    10 µg BrO3/l

    581

    0

    <0.46

    1.854

    0

    Cadmium (Total)

    B002

    5 µg Cd/l

    645

    0

    <0.062

    <0.062

    0

    Chromium (Total)

    B004

    50 µg Cr/l

    645

    0

    <0.18

    0.33

    0

    Copper (Total)

    A024A

    2 mg Cu/l

    649

    0

    <0.22

    0.445

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    442

    0

    <3.6

    <3.6

    0

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    8,195

    1

    0

    0

    0

    Enterococci (Confirmed)

    C003

    0 number/100 ml

    650

    0

    0

    0

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    428

    0

    <0.11

    <0.11

    0

    Lead (10 – will apply 25.12.2013)

    B007B

    10 µg Pb/l

    649

    0

    <0.16

    3.05

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    435

    0

    <0.037

    <0.037

    0

    Nickel (Total) 

    B006A 

    20 µg Ni/l

    649

    1

    <1.2

    7.5

    1

    Nitrate (Total)

    A012

    50 mg NO3/l

    646

    0

    <2.213

    <16.3762

    0

    Nitrite – Consumer’s Taps

    A013A

    0.5 mg NO2/l

    646

    0

    <0.015

    <0.015

    0

    Nitrite/Nitrate formula

    A013C

    1 mg/l

    646

    0

    <0.05

    <0.33

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    556

    0

    0

    0.024

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    524

    0

    <0.0078

    0.01775

    0

    Pesticides Aldrin

    P002

    0.03 µg/l

    525

    0

    <0.0065

    <0.0065

    0

    Pesticides Asulam

    P133

    0.1 µg/l

    521

    0

    <0.011

    <0.011

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    41

    0

    <0.0079

    0.016

    0

    Pesticides Diazinon

    P024

    0.1 µg/l

    33

    0

    <0.015

    <0.015

    0

    Pesticides Dicamba

    P025

    0.1 µg/l

    25

    0

    <0.023

    <0.023

    0

    Pesticides Dieldrin

    P028

    0.03 µg/l

    525

    0

    <0.007

    <0.007

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    530

    0

    <0.0064

    <0.0064

    0

    Pesticides Heptachlor

    P043

    0.03 µg/l

    524

    0

    <0.0081

    <0.0081

    0

    Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

    P044

    0.03 µg/l

    524

    0

    <0.0057

    <0.0057

    0

    Pesticides Ioxynil

    P049

    0.1 µg/l

    16

    0

    <0.0069

    <0.0069

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    522

    0

    <0.011

    <0.01177

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    520

    0

    <0.0087

    <0.0087

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    185

    0

    <0.008

    <0.008

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    8

    0

    <0.012

    <0.012

    0

    Pesticides Quinmerac

    P244

    0.1 µg/l

    8

    0

    <0.006

    <0.006

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    33

    0

    <0.012

    <0.012

    0

    Polycyclic Aromatic Hydrocarbons (Total by Calculation)

    B011F

    0.1 µg/l

    651

    0

    0

    0

    0

    Selenium (Total)

    B009

    10 µg Se/l

    645

    0

    <0.22

    0.3854

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    447

    0

    0

    0

    0

    Trihalomethanes (Total by Calculation)

    D011

    100 µg/l

    650

    0

    3

    63.56

    0

    Totals

    27,196

    2

    Table 10: Quality of water at consumer’s tap (zones) – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    No. of zones failing standard

    Aluminium (Total)

    A021

    200 µg Al/l

    3,047

    0

    <44

    47

    0

    Colour

    A001

    20 mg/l Pt/Co

    3,052

    0

    <0.4

    4.247

    0

    Iron (Total)

    A022

    200 µg Fe/l

    3,048

    7

    <34

    120

    7

    Manganese (Total)

    A023

    50 µg Mn/l

    3,047

    2

    <7.1

    9.904

    2

    Odour

    A003

    0 Dilution number at 25°C

    3,055

    5

    0

    0

    4

    Sodium (Total)

    A009

    200 mg Na/l

    645

    0

    2.646

    39.54

    0

    Taste (Taste Quant)

    A004

    0 Dilution number at 25°C

    3,041

    2

    0

    0

    1

    Tetrachloromethane (Total)

    D008

    3 µg/l

    434

    0

    <0.21

    <0.21

    0

    Turbidity

    A002

    4 NTU

    3,051

    0

    <0.24

    <0.3

    0

    Totals

    22,420

    16

    Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Ammonium (Total)

    A014

    0.5 mg NH4/l

    647

    0

    <0.01

    <0.01

    Chloride

    D002A

    250 mg Cl/l

    436

    0

    <10.1

    36.63

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    8,195

    9

    0

    0

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    3,041

    N/A

    0

    7

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    3,053

    0

    66

    460

    Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

    A006

    6.5 – 9.5 pH Value

    3,048

    0

    7.3

    8.4

    Residual Disinfectant – Free

    C009

    No abnormal change

    8,213

    N/A

    0.06

    1.01

    Residual Disinfectant – Total

    C010

    No abnormal change

    8,213

    N/A

    0.16

    1.08

    Sulphate

    A007

    250 mg SO4/l

    436

    0

    <8.9

    62

    Total Organic Carbon

    A017

    No abnormal change

    427

    N/A

    <0.57

    2.172

    Totals

    35,709

    9

    What are the drinking water standards?

    Drinking water must be ‘wholesome’ and this is defined in law mainly by setting standards for a wide range of substances, organisms and properties of water in regulations. There is an additional requirement to make sure that it does not contain anything else that might be a potential danger to human health, as identified by risk assessment. The standards are set to be protective of public health and the definition of wholesome includes factors that might affect the look, smell or taste of the water which needs to be acceptable to consumers. There is good agreement amongst experts worldwide on the science behind the setting of health based standards for drinking water and this expert evidence is documented by the World Health Organisation in the Guidelines for Drinking Water Quality. You can look up all the background information to standards of water safety here: Guidelines for drinking-water quality: Fourth edition incorporating the first and second addenda (who.int). The legal standards in the UK were based on those which were set in Europe in the Drinking Water Directive 1998 and subsequent revisions, together with national standards set to maintain the high quality of water already achieved. The standards are strict and include wide safety margins. They cover:

    • micro-organisms

    • chemicals such as nitrate and pesticides

    • metals such as lead and copper

    • the way water looks and how it tastes

    The full regulations can be found The Water Supply (Water Quality) Regulations 2016 (legislation.gov.uk). An explanation of the organisms and substances tested for regularly can be found in the Chief Inspector’s Report. This guide also explains how drinking water is regulated in England and Wales.

    Terms Explained

    Parameter: Substance or organism tested for routinely in drinking water.

    Directive requirements: These are the standards and specifications set in the EU Drinking Water Directive and were adopted into national legislation.

    National requirements: These are national standards and specifications in the regulations which apply only in the England and Wales.

    Concentration or value or specification: Maximum or minimum or range allowed in drinking water.

    Point of compliance: The point where the legal standards apply, normally this is the consumers tap but it may be at the water works.

    µg/l: Micrograms per litre (parts per billion).

    mg/l: Milligrams per litre (parts per million).

    Microbiological Parameters

    Parameters

    Concentration or Value maximum)

    Units of Measurement

    Point of compliance

    Enterococci

    0

    number/100ml

    Consumers’ taps

    Escherichia coli (E. coli)

    0

    number/100ml

    Consumers’ taps

    Table 1: Part I – Directive requirements

    Parameters

    Concentration or Value maximum)

    Units of Measurement

    Point of compliance

    Coliform bacteria

    0

    number/100ml

    Service reservoirs* and water treatment works

    Escherichia coli (E. coli)

    0

    number/100ml

    Service reservoirs and water treatment works

    Table 2: Part II – National requirements

    Note: *Compliance required as to 95% of samples from each service reservoir

    Chemical Parameters

    Parameters

    Concentration or Value maximum)

    Units of Measurement

    Point of compliance

    Acrylamide

    0.10

    µg/l

    (i)

    Antimony

    5.0

    µgSb/l

    Consumers’ taps

    Arsenic

    10

    µgAs/l

    Consumers’ taps

    Benzene

    1.0

    µg/l

    Consumers’ taps

    Benzo(a)pyrene

    0.010

    µg/l

    Consumers’ taps

    Boron

    1.0

    mgB/l

    Consumers’ taps

    Bromate

    10

    µgBrO3/l

    Consumers’ taps

    Cadmium

    5.0

    µgCd/l

    Consumers’ taps

    Chromium

    50

    µgCr/l

    Consumers’ taps

    Copper(ii)

    2.0

    mgCu/l

    Consumers’ taps

    Cyanide

    50

    µgCN/l

    Consumers’ taps

    1, 2 dichloroethane

    3.0

    µg/l

    Consumers’ taps

    Epichlorohydrin

    0.10

    µg/l

    (i)

    Fluoride

    1.5

    mgF/l

    Consumers’ taps

    Lead (ii)

    10

    µgPb/l

    Consumers’ taps

    Mercury

    1.0

    µgHg/l

    Consumers’ taps

    Nickel (ii)

    20

    µgNi/l

    Consumers’ taps

    Nitrate (iii)

    50

    mgNO3/l

    Consumers’ taps

    Nitrite (iii)

    0.50

    mgNO2/l

    Consumers’ taps

     

    0.10

     

    Treatment works

    Pesticides (iv)(v)

       

    Aldrin

    0.030

    µg/l

    Consumers’ taps

    Dieldrin

    0.030

    µg/l

    Consumers’ taps

    Heptachlor

    0.030

    µg/l

    Consumers’ taps

    Heptachlor epoxide

    0.030

    µg/l

    Consumers’ taps

    other pesticides

    0.10

    µg/l

    Consumers’ taps

    Pesticides: Total (vi)

    0.50

    µg/l

    Consumers’ taps

    Polycyclic aromatic hydrocarbons (vii)

    0.10

    µg/l

    Consumers’ taps

    Selenium

    10

    µgSe/l

    Consumers’ taps

    Tetrachloroethene and Trichloroethene (viii)

    10

    µg/l

    Consumers’ taps

    Trihalomethanes: Total (ix)

    100

    µg/l

    Consumers’ taps

    Vinyl chloride

    0.50

    µg/l

    (i)

    Table 3: Part I – Directive requirements

    Notes:

    1. The parametric value refers to the residual monomer concentration in the water as calculated according to specifications of the maximum release from the corresponding polymer in contact with the water. This is controlled by product specification.
    2. See also regulation 6(6)
    3. See also regulation 4(2)(d)
    4. See the definition of “pesticides and related products” in regulation 2
    5. The parametric value applies to each individual pesticide.
    6. “Pesticides: Total” means the sum of the concentrations of the individual pesticides detected and quantified in the monitoring procedure.
      The specified compounds are:

     – benzo(b)fluoranthene
     – benzo(k)fluoranthene
     – benzo(ghi)perylene
     – indeno(1,2,3-cd)pyrene.

    1. The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.

    The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.

    1. The specified compounds are:

     – chloroform
     – bromoform
     – dibromochloromethane
     – bromodichloromethane.

    The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.

    National Requirements

    Parameters

    Concentration or Value (maximum unless otherwise stated)

    Units of Measurement

    Point of compliance

    Aluminium

    200

    µgAl/l

    Consumers’ taps

    Colour

    20

    mg/l Pt/Co

    Consumers’ taps

    Iron

    200

    µgFe/l

    Consumers’ taps

    Manganese

    50

    µgMn/l

    Consumers’ taps

    Odour

    Acceptable to consumers and no abnormal change

     

    Consumers’ taps

    Sodium

    200

    mgNa/l

    Consumers’ taps

    Taste

    Acceptable to consumers and no abnormal change

     

    Consumers’ taps

    Tetrachloromethane

    3

    µg/l

    Consumers’ taps

    Turbidity

    4

    NTU

    Consumers’ taps

    Table 4: National requirements

    Print child page

    PRT (Portsmouth Water Ltd)

    Report Data Range: For the whole year 2021

    Table 1: Quality of water leaving service treatment works – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    Nitrite (Total)

    A013B

    0.1 mg NO2/l

    118

    0

    < 0.011

    0.01462

    0

    Totals

    118

    0

    Table 2: Quality of water leaving service treatment works – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    3,003

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    3,003

    0

    0

    0

    0

    Totals

    6,006

    0

    Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    2,978

    N/A

    0

    3

    Residual Disinfectant – Free

    C009

    No abnormal change

    3,007

    N/A

    0.3

    0.8

    Residual Disinfectant – Total

    C010

    No abnormal change

    3,007

    N/A

    0.33

    0.87

    Turbidity – Indicator

    A002A

    1 NTU

    3,002

    0

    <0.28

    0.36491

    Totals

    11,994

    0

    Table 4: Quality of water leaving service reservoirs – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of reservoirs failing standard

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    1,460

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    1,460

    0

    0

    0

    0

    Totals:

    2,920

    0

    Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    1,446

    N/A

    0

    6

    Residual Disinfectant – Free

    C009

    No abnormal change

    1,464

    N/A

    0.2

    0.68

    Residual Disinfectant – Total

    C010

    No abnormal change

    1,464

    N/A

    0.27

    0.74

    Totals:

    4,374

    0

    Table 9: Quality of water at consumer’s tap (zones) – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of zones failing standard

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    129

    0

    <0.12

    <0.12

    0

    Antimony

    B008A

    5 µg Sb/l

    118

    0

    <0.0947

    0.4677

    0

    Arsenic (Total)

    B001A

    10 µg As/l

    118

    0

    0.2156

    <1

    0

    Benzene (Total)

    F002

    1 µg/l

    129

    0

    <0.02

    <0.02

    0

    Benzo[a]Pyrene (Total)

    D007

    0.01 µg/l

    124

    0

    <0.003

    <0.003

    0

    Boron

    D005A

    1 mg B/l

    120

    0

    <0.14

    <0.14

    0

    Bromate

    F003

    10 µg BrO3/l

    119

    0

    <0.8

    <0.8

    0

    Cadmium (Total)

    B002

    5 µg Cd/l

    124

    0

    <0.22

    <0.22

    0

    Chromium (Total)

    B004

    50 µg Cr/l

    124

    0

    <2.3

    <2.3

    0

    Copper (Total)

    A024A

    2 mg Cu/l

    128

    0

    <0.172

    1.55996

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    119

    0

    <2

    8.54

    0

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    1,909

    0

    0

    0

    0

    Enterococci (Confirmed)

    C003

    0 number/100 ml

    122

    0

    0

    0

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    119

    0

    <0.0508

    0.434

    0

    Lead (10 – will apply 25.12.2013)

    B007B

    10 µg Pb/l

    129

    0

    <0.5

    5.72

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    120

    0

    <0.04

    0.05

    0

    Nickel (Total) 

    B006A 

    20 µg Ni/l

    128

    3

    <1.3

    52.511

    2

    Nitrate (Total)

    A012

    50 mg NO3/l

    124

    0

    22.275

    45.725

    0

    Nitrite – Consumer’s Taps

    A013A

    0.5 mg NO2/l

    124

    0

    <0.011

    0.02325

    0

    Nitrite/Nitrate formula

    A013C

    1 mg/l

    124

    0

    0.4455

    0.91825

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    135

    0

    0

    0.05344

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    130

    0

    <0.007

    <0.007

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    130

    0

    0.00362

    0.01069

    0

    Pesticides Bentazone

    P006

    0.1 µg/l

    130

    0

    <0.007

    <0.007

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    131

    0

    <0.005

    <0.025

    0

    Pesticides Mesosulfuron-methyl

    P234

    0.1 µg/l

    130

    0

    <0.004

    <0.005

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    130

    0

    <0.008

    <0.008

    0

    Pesticides Picloram (Total)

    P122

    0.1 µg/l 

    130

    0

    <0.008

    <0.015

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    125

    0

    <0.005

    0.04574

    0

    Polycyclic Aromatic Hydrocarbons (Total by Calculation)

    B011F

    0.1 µg/l

    122

    0

    0

    0

    0

    Selenium (Total)

    B009

    10 µg Se/l

    118

    0

    <0.4112

    4.062

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    130

    0

    0

    0

    0

    Trihalomethanes (Total by Calculation)

    D011

    100 µg/l

    128

    0

    0.5046

    71.8783

    0

    Totals

    5,920

    3

    Table 10: Quality of water at consumer’s tap (zones) – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    No. of zones failing standard

    Aluminium (Total)

    A021

    200 µg Al/l

    602

    2

    <8.1

    64.429

    2

    Colour

    A001

    20 mg/l Pt/Co

    667

    0

    <1.23

    1.7596

    0

    Iron (Total)

    A022

    200 µg Fe/l

    612

    0

    <13.8

    39.334

    0

    Manganese (Total)

    A023

    50 µg Mn/l

    613

    0

    <2.5

    <2.5

    0

    Odour

    A003

    0 Dilution number at 25°C

    658

    2

    0

    0

    2

    Sodium (Total)

    A009

    200 mg Na/l

    120

    0

    <9.1

    14.958

    0

    Taste (Taste Quant)

    A004

    0 Dilution number at 25°C

    657

    0

    0

    0

    0

    Tetrachloromethane (Total)

    D008

    3 µg/l

    124

    0

    <0.11

    <0.11

    0

    Turbidity

    A002

    4 NTU

    672

    0

    <0.28

    0.5698

    0

    Totals

    4,725

    4

    Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Ammonium (Total)

    A014

    0.5 mg NH4/l

    626

    0

    <0.073

    <0.073

    Chloride

    D002A

    250 mg Cl/l

    120

    0

    19.863

    30.89

    Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    122

    0

    0

    0

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    1,909

    2

    0

    0

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    712

    N/A

    0

    12

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    667

    0

    492

    618

    Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

    A006

    6.5 – 9.5 pH Value

    667

    0

    7.11

    7.8196

    Residual Disinfectant – Free

    C009

    No abnormal change

    1,915

    N/A

    0.1

    0.66

    Residual Disinfectant – Total

    C010

    No abnormal change

    1,915

    N/A

    0.1816

    0.72

    Sulphate

    A007

    250 mg SO4/l

    120

    0

    10.721

    22.658

    Total Organic Carbon

    A017

    No abnormal change

    119

    N/A

    <0.5

    1.48

    Totals

    8,892

    2

    ALB (Albion Water Ltd)

    Report Data Range: For the whole year 2021

    Table 9: Quality of water at consumer’s tap (zones) – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of zones failing standard

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    8

    0

    <0.16

    <0.16

    0

    Antimony

    B008A

    5 µg Sb/l

    8

    0

    0.02

    0.54

    0

    Arsenic (Total)

    B001A

    10 µg As/l

    8

    0

    0.13

    1.26

    0

    Benzene (Total)

    F002

    1 µg/l

    8

    0

    <0.06

    <0.06

    0

    Benzo[a]Pyrene (Total)

    D007

    0.01 µg/l

    8

    0

    <0.00057

    <0.00057

    0

    Boron

    D005A

    1 mg B/l

    8

    0

    <0.032

    0.0715

    0

    Bromate

    F003

    10 µg BrO3/l

    8

    0

    <0.15

    2.8

    0

    Cadmium (Total)

    B002

    5 µg Cd/l

    8

    0

    <0.01

    0.04

    0

    Chromium (Total)

    B004

    50 µg Cr/l

    8

    0

    <0.04

    0.22

    0

    Copper (Total)

    A024A

    2 mg Cu/l

    8

    0

    0.0033

    1.15

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    8

    0

    <5.5

    <5.5

    0

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    24

    0

    0

    0

    0

    Enterococci (Confirmed)

    C003

    0 number/100 ml

    8

    0

    0

    0

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    8

    0

    0.13

    0.48

    0

    Lead (10 – will apply 25.12.2013)

    B007B

    10 µg Pb/l

    8

    0

    0.13

    2.32

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    8

    0

    <0.06

    <0.06

    0

    Nickel (Total) 

    B006A 

    20 µg Ni/l

    8

    0

    0.74

    8.03

    0

    Nitrate (Total)

    A012

    50 mg NO3/l

    8

    0

    6.8

    41.6

    0

    Nitrite – Consumer’s Taps

    A013A

    0.5 mg NO2/l

    8

    0

    <0.002

    <0.002

    0

    Nitrite/Nitrate formula

    A013C

    1 mg/l

    8

    0

    0.14

    0.83

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    9

    0

    0

    0.031

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    9

    0

    <0.012

    <0.012

    0

    Pesticides 2 4-DB

    P082

    0.1 µg/l

    9

    0

    <0.017

    <0.018

    0

    Pesticides 2,4,5-T

    P076

    0.1 µg/l

    9

    0

    <0.011

    <0.016

    0

    Pesticides Ametryn

    P222

    0.1 µg/l

    5

    0

    <0.003

    <0.004

    0

    Pesticides Asulam

    P133

    0.1 µg/l

    4

    0

    <0.008

    <0.014

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    9

    0

    <0.004

    <0.005

    0

    Pesticides Bentazone

    P006

    0.1 µg/l

    9

    0

    <0.002

    <0.004

    0

    Pesticides Bromoxynil

    P008

    0.1 µg/l

    5

    0

    <0.009

    <0.009

    0

    Pesticides Carbendazim (Total)

    P150

    0.1 µg/l

    5

    0

    <0.003

    <0.003

    0

    Pesticides Carbetamide 

    P010

    0.1 µg/l

    9

    0

    <0.008

    <0.01

    0

    Pesticides Chloridazon

    P162

    0.1 µg/l

    4

    0

    <0.008

    <0.022

    0

    Pesticides Chlormequat

    P163

    0.1 µg/l

    4

    0

    <0.003

    <0.003

    0

    Pesticides Chlorothalonil

    P015

    0.1 µg/l

    4

    0

    <0.006

    <0.014

    0

    Pesticides Chlortoluron

    P014

    0.1 µg/l

    9

    0

    <0.006

    <0.007

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    9

    0

    <0.011

    0.015

    0

    Pesticides Dicamba

    P025

    0.1 µg/l

    9

    0

    <0.012

    <0.014

    0

    Pesticides Dichlorprop

    P026

    0.1 µg/l

    9

    0

    <0.011

    <0.017

    0

    Pesticides Diuron

    P032

    0.1 µg/l

    9

    0

    <0.009

    <0.01

    0

    Pesticides Fenpropidin

    P168

    0.1 µg/l

    4

    0

    <0.006

    <0.007

    0

    Pesticides Fenpropimorph

    P037

    0.1 µg/l

    4

    0

    <0.004

    <0.005

    0

    Pesticides Fenpropimorph

    P037

    0.1 µg/l

    4

    0

    <0.004

    <0.005

    0

    Pesticides Fluroxypyr

    P040

    0.1 µg/l

    9

    0

    <0.009

    <0.012

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    4

    0

    <0.005

    <0.025

    0

    Pesticides Ioxynil

    P049

    0.1 µg/l

    5

    0

    <0.007

    <0.009

    0

    Pesticides Isoproturon

    P048

    0.1 µg/l

    9

    0

    <0.005

    <0.006

    0

    Pesticides Linuron

    P051

    0.1 µg/l

    4

    0

    <0.007

    <0.012

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    9

    0

    <0.008

    <0.012

    0

    Pesticides MCPB

    P065

    0.1 µg/l

    9

    0

    <0.018

    <0.018

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    9

    0

    <0.007

    <0.009

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    9

    0

    <0.007

    0.02

    0

    Pesticides Metazachlor

    P203

    0.1 µg/l 

    4

    0

    <0.006

    <0.007

    0

    Pesticides Monuron

    P113

    0.1 µg/l

    4

    0

    <0.007

    <0.007

    0

    Pesticides Pendimethalin

    P118

    0.1 µg/l

    4

    0

    <0.009

    <0.02

    0

    Pesticides Pentachlorophenol

    P060

    0.1 µg/l

    9

    0

    <0.015

    <0.02

    0

    Pesticides Picloram (Total)

    P122

    0.1 µg/l

    9

    0

    <0.013

    <0.019

    0

    Pesticides Propazine

    P066

    0.1 µg/l

    5

    0

    <0.004

    <0.007

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    4

    0

    <0.007

    0.014

    0

    Pesticides Quinmerac

    P244

    0.1 µg/l

    4

    0

    <0.006

    <0.007

    0

    Pesticides Simazine

    P073

    0.1 µg/l

    5

    0

    <0.004

    <0.005

    0

    Pesticides Terbutryn

    P077

    0.1 µg/l

    9

    0

    <0.003

    <0.005

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    9

    0

    <0.015

    <0.028

    0

    Polycyclic Aromatic Hydrocarbons (Total by Calculation)

    B011F

    0.1 µg/l

    8

    0

    0

    0.0005

    0

    Selenium (Total)

    B009

    10 µg Se/l

    8

    0

    0.13

    0.64

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    8

    0

    0

    0

    0

    Trihalomethanes (Total by Calculation)

    D011

    100 µg/l

    8

    0

    10.22

    17.05

    0

    Totals

    488

    0

    Table 10: Quality of water at consumer’s tap (zones) – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    No. of zones failing standard

    Aluminium (Total)

    A021

    200 µg Al/l

    8

    0

    <6.9

    <14.5

    0

    Colour

    A001

    20 mg/l Pt/Co

    8

    0

    <2.9

    <2.9

    0

    Iron (Total)

    A022

    200 µg Fe/l

    8

    0

    <3.72

    9.69

    0

    Manganese (Total)

    A023

    50 µg Mn/l

    8

    0

    <0.3

    <0.85

    0

    Odour

    A003

    0 Dilution number at 25°C

    8

    0

    0

    0

    0

    Sodium (Total)

    A009

    200 mg Na/l

    8

    0

    9.42

    39.5

    0

    Taste (Taste Quant)

    A004

    0 Dilution number at 25°C

    8

    0

    0

    0

    0

    Tetrachloromethane (Total)

    D008

    3 µg/l

    8

    0

    <0.16

    <0.16

    0

    Turbidity

    A002

    4 NTU

    8

    0

    <0.13

    0.3

    0

    Totals

    72

    0

    Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Ammonium (Total)

    A014

    0.5 mg NH4/l

    8

    0

    <0.008

    0.283

    Chloride

    D002A

    250 mg Cl/l

    8

    0

    17.2

    64.6

    Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    8

    0

    0

    0

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    24

    0

    0

    0

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    8

    N/A

    0

    32

    Colony Counts After 48 Hours At 37øc (Colony Counts)

    C013

    No abnormal change

    8

    N/A

    0

    26

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    8

    0

    488

    696

    Gross Alpha

    F004

    0.1 Bq/l

    2

    0

    <0.022

    <0.024

    Gross Beta

    F005

    1 Bq/l

    2

    0

    0.181

    0.182

    Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

    A006

    6.5 – 9.5 pH Value

    8

    0

    7.38

    7.76

    Residual Disinfectant – Free

    C009

    No abnormal change

    12

    N/A

    0.03

    0.56

    Residual Disinfectant – Total

    C010

    No abnormal change

    24

    N/A

    0.1

    1.18

    Sulphate

    A007

    250 mg SO4/l

    8

    0

    34.9

    57.6

    Total Organic Carbon

    A017

    No abnormal change

    8

    N/A

    <0.7

    2.6

    Totals

    137

    0

    Accessibility statement for the Drinking Water Inspectorate reporting portal (dwi-reporting@defra.gov.uk)

    Accessibility statement for the Drinking Water Inspectorate reporting portal (dwi-reporting@defra.gov.uk)

    This accessibility statement applies to the Drinking Water Inspectorate website reporting portal at dwi-reporting@defra.gov.uk. 

    This website is run by the Drinking Water Inspectorate and is for water companies to make statutory submissions to the Drinking Water Inspectorate. It is not intended to be used by members of the public or anyone outside of the authorised water company personnel.

    How accessible this website is

    We know some parts of this website are not fully accessible:

    • colours, contrast levels and fonts cannot be easily changed
    • zooming in up to 300% causes text to spill off the screen
    • navigating most of the site using just a keyboard is not possible
    • navigating most of the website using speech recognition software is not possible
    • listening to most of the website using a screen reader (including the most recent versions of JAWS, NVDA and VoiceOver) is not possible
    • the text will not reflow in a single column when you change the size of the browser window
    • you cannot modify the line height or spacing of text
    • most older PDF documents are not fully accessible to screen reader software
    • online forms are difficult to navigate using just a keyboard
    • you cannot skip to the main content when using a screen reader

    Feedback and contact information

    If you need information on this website in a different format like accessible PDF, large print, easy read, audio recording or braille:

    • email dwi.enquiries@defra.gov.uk
    • call 0300 068 6400

    We’ll consider your request and get back to you in 14 days.

    Reporting accessibility problems with this website

    We’re always looking to improve the accessibility of this website. If you find any problems not listed on this page or think we’re not meeting accessibility requirements, contact: dwi.enquiries@defra.gov.uk.

    Enforcement procedure

    The Equality and Human Rights Commission (EHRC) is responsible for enforcing the Public Sector Bodies (Websites and Mobile Applications) (No. 2) Accessibility Regulations 2018 (the ‘accessibility regulations’). If you’re not happy with how we respond to your complaint, contact the Equality Advisory and Support Service (EASS).

    Technical information about this website’s accessibility

    DWI is committed to making its website accessible, in accordance with the Public Sector Bodies (Websites and Mobile Applications) (No. 2) Accessibility Regulations 2018.

    Compliance status

    This website is partially compliant with the Web Content Accessibility Guidelines version 2.1 AA standard, due to the non-compliances and exemptions listed above.

    Non-accessible content

    The content listed below is non-accessible for the following reasons.

    Non-compliance with the accessibility regulations

    • change colours, contrast levels and fonts cannot be easily changed
    • zooming in up to 300% causes text to spill off the screen
    • navigating most of the site using just a keyboard is not possible
    • navigating most of the website using speech recognition software is not possible
    • listening to most of the website using a screen reader (including the most recent versions of JAWS, NVDA and VoiceOver) is not possible
    • the text will not reflow in a single column when you change the size of the browser window
    • you cannot modify the line height or spacing of text
    • most older PDF documents are not fully accessible to screen reader software
    • online forms are difficult to navigate using just a keyboard
    • you cannot skip to the main content when using a screen reader

    Disproportionate burden

    www.dwi-reporting.defra.gov.uk is portal for authorised water company personnel to upload statutory data to the Drinking Water Inspectorate system. The estimated number of people that will need to use this website is estimated to be <100 in total and approximately less than 20 visits per week. It is not intended for use by the public. The main public facing website of the DWI is at dwi.gov.uk

    Content that’s not within the scope of the accessibility regulations

    www.dwi-reporting.defra.gov.uk does not contain any content outside the scope of the accessibility regulations.

    PDFs and other documents

    There are no PDFs or other documents accessed via this site.

    What we’re doing to improve accessibility

    In order to meet the AA accessibility standards, we need an upgrade to our IT system to allow a modern interface. We have several other IT projects that need to be upgraded serving a larger number of users and these will be prioritised over this site. However, we plan to upgrade this site to meet the AA accessibility standard by 31 December 2024

    Preparation of this accessibility statement

    This statement was prepared on 12 August 2021. It was last reviewed on 12 August 2021.

    This website has not been formally tested against the accessibility standards.

    IWNL (Independent Water Networks Ltd)

    Report Data Range: For the whole year 2021

    Table 9: Quality of water at consumer’s tap (zones) – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of zones failing standard

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    101

    0

    <0.16

    <0.16

    0

    Antimony

    B008A

    5 µg Sb/l

    117

    0

    0.0218

    0.5264

    0

    Arsenic (Total)

    B001A

    10 µg As/l

    117

    0

    0.0918

    1.9064

    0

    Benzene (Total)

    F002

    1 µg/l

    101

    0

    <0.06

    <0.09

    0

    Benzo[a]Pyrene (Total)

    D007

    0.01 µg/l

    101

    0

    <0.00057

    <0.000962

    0

    Boron

    D005A

    1 mg B/l

    117

    0

    0.0101198

    0.12732

    0

    Bromate

    F003

    10 µg BrO3/l

    117

    0

    <0.15

    5.36

    0

    Cadmium (Total)

    B002

    5 µg Cd/l

    117

    0

    <0.01

    0.3782

    0

    Chromium (Total)

    B004

    50 µg Cr/l

    117

    0

    <0.04

    5.753

    0

    Copper (Total)

    A024A

    2 mg Cu/l

    117

    0

    <0.00049

    0.53134

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    117

    0

    <1.2

    <12.47

    0

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    311

    0

    0

    0

    0

    Enterococci (Confirmed)

    C003

    0 number/100 ml

    111

    0

    0

    0

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    117

    0

    <0.0418

    1.1722

    0

    Lead (10 – will apply 25.12.2013)

    B007B

    10 µg Pb/l

    117

    0

    <0.04

    3.2464

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    117

    0

    <0.06

    <0.06

    0

    Nickel (Total) 

    B006A 

    20 µg Ni/l

    117

    2

    <0.2106

    65.26

    2

    Nitrate (Total)

    A012

    50 mg NO3/l

    116

    0

    <2.11

    43.558

    0

    Nitrite – Consumer’s Taps

    A013A

    0.5 mg NO2/l

    116

    0

    0.00034

    0.12267

    0

    Nitrite/Nitrate formula

    A013C

    1 mg/l

    116

    0

    0

    0.8715

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    58

    0

    0

    0.065

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    58

    0

    <0.007

    0.055

    0

    Polycyclic Aromatic Hydrocarbons (Total by Calculation)

    B011F

    0.1 µg/l

    101

    0

    0

    0.0698

    0

    Radon

    F101

    100 Bq/l

    30

    0

    <1.1

    3.33

    0

    Selenium (Total)

    B009

    10 µg Se/l

    117

    0

    <0.08

    1.9906

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    101

    0

    0

    0.4802

    0

    Trihalomethanes (Total by Calculation)

    D011

    100 µg/l

    101

    0

    2.8158

    68.8084

    0

    Totals

    3,043

    2

    Table 10: Quality of water at consumer’s tap (zones) – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    No. of zones failing standard

    Aluminium (Total)

    A021

    200 µg Al/l

    117

    0

    <6.9

    141.01

    0

    Colour

    A001

    20 mg/l Pt/Co

    128

    0

    <2.9

    <8.68

    0

    Iron (Total)

    A022

    200 µg Fe/l

    117

    0

    <3.72

    164.28

    0

    Manganese (Total)

    A023

    50 µg Mn/l

    117

    0

    <0.3

    9.6134

    0

    Odour

    A003

    0 Dilution number at 25°C

    129

    0

    0

    0

    0

    Sodium (Total)

    A009

    200 mg Na/l

    117

    0

    3.9636

    77.402

    0

    Taste (Taste Quant)

    A004

    0 Dilution number at 25°C

    128

    0

    0

    0

    0

    Tetrachloromethane (Total)

    D008

    3 µg/l

    101

    0

    <0.13

    <0.2286

    0

    Turbidity

    A002

    4 NTU

    128

    1

    <0.13

    4.2587

    1

    Totals

    1,082

    1

    Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Ammonium (Total)

    A014

    0.5 mg NH4/l

    128

    0

    <0.008

    0.23423

    Chloride

    D002A

    250 mg Cl/l

    128

    0

    7.116

    95.524

    Clostridum Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    129

    0

    0

    0

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    310

    3

    0

    1

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    128

    N/A

    0

    210

    Colony Counts After 48 Hours At 37øc (Colony Counts)

    C013

    No abnormal change

    1

    N/A

    1

    1

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    128

    0

    154.03

    930.21

    Gross Alpha

    F004

    0.1 Bq/l

    34

    0

    <0.012

    0.093

    Gross Beta

    F005

    1 Bq/l

    34

    0

    0.013

    0.261

    Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

    A006

    6.5 – 9.5 pH Value

    128

    0

    6.8567

    8.3908

    Residual Disinfectant – Free

    C009

    No abnormal change

    314

    N/A

    0.02

    0.7325

    Residual Disinfectant – Total

    C010

    No abnormal change

    314

    N/A

    0.1

    0.9885

    Sulphate

    A007

    250 mg SO4/l

    128

    0

    9.3098

    195.07

    Total Organic Carbon

    A017

    No abnormal change

    128

    N/A

    <0.7

    4.2927

    Tritium

    F006

    100 Bq/l

    25

    0

    <5.6

    <10

    Totals

    2,057

    3

    The risk to water safety posed by eco-building design and the absence of effective procedures for scrutiny of the water supply aspects of planning applications

    In August 2013, the Inspectorate provided on-site technical support to a local authority when carrying out a private supply risk assessment at premises owned by the local authority. The premises was a public building providing educational facilities, including water sports for schools in the area. The design was intended to be an eco-building and the private supply, which derived from a shallow well in gravel strata, provided water for all domestic purposes other than drinking (including heating, toilet flushing, hand-washing and showering). The building has a separate public supply of water for the provision of drinking water.

    The risk assessment was triggered by complaints from the manager of the centre about the water being discoloured (see Figure 14) and there was staining of the sanitary wear, including the showers. When the facility was first granted planning permission and built, the new private supply was added to the local authority private supply record, however, at that time none of the parties involved (planners, engineers, council staff) understood that while the supply was not intended for drinking, it was still being used for domestic purposes and therefore needed to be wholesome as defined by the regulations.

    Figure 14: Discoloured water at a handbasin

    Figure 14: Discoloured water at a handbasin

    The well water is pumped into a tank and then passes to a treatment system comprising a sand filter for particle and turbidity removal, an ion-exchange unit (possibly for water softening but no design records as to purpose exist) and an ultraviolet (UV) disinfection system, all of which is powered by electricity generated on site by wind and photovoltaic cells. There was a history of interruptions to the power supply with consequential losses of the water supply and members of staff were in the habit of resetting the system whenever this occurred. This action prevented the correct cycling of the backwashing treatment programme and was therefore leading to the filters and the ion-exchange media becoming saturated and failing to adequately treat the water supply.

    This case study demonstrates a common problem that arises in relation to public buildings, especially eco buildings, namely those who finance, design and commission such water systems frequently fail to make provision for onward safe operation and do not recognise or have regard for the regulatory regime for water supplied for domestic purposes. In this case, in response to an obvious design fault with the power supply, staff using the building were accessing and operating a critical part of the water system without having any knowledge or understanding of the consequences of their actions for the safety and quality of the water. Workarounds, such as resetting a system each time a fault occurs, introduce risks and hazards that go beyond causing the water treatment to fail and the water supply to be unwholesome, they potentially create risks to the health and safety of staff or users of the facility.

    In premises served by both a private and a public water supply, specific risks can arise to the public water supply, therefore it is important that the water company is notified by the premises owner, as required by the Water Fittings Regulations 1999, so an inspection can be carried out to verify that the supply arrangements are satisfactory. Following the risk assessment the local authority has put in place procedures for the food safety team (who deal with private water supplies) to be notified of planning applications for new private water supplies. As regards the ecobuilding it was decided to abandon the private supply and rely solely on the mains water supply by installing two public supply storage tanks.

    This audit enabled the Inspectorate to verify that the risk assessment tool provided to local authorities places appropriate weight on the management aspects of private supplies so that the risks illustrated in this case study will be identified and acted upon.

    The Inspectorate recommends that local authorities put in place effective procedures for scrutinising the water supply aspects of planning applications and always notify the local water company whenever it is discovered that both a public and a private water supply serve a premises.

    Anglian Water Services Limited – Ringstead works Nitrate

    Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

    Reference: ANH-2023-00011

    Version Number: 1

    Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Anglian Water Services Limited, with registered number 02366656 (hereinafter called ‘the Company’).

    Assets Affected:

    Asset Name

    Reference

    Ringstead Supply System

    SSC-001-RIN

    Sedgeford Source

    CSED0WV

    Sedgeford Source Borehole 1

    ASED1CV

    Sedgeford Source Borehole 2

    ASED2CV

    Ringstead works

    TSED

    Hunstanton PWSZ

    ZFE42

    Table 1: List of assets affected and associated reference numbers

    Details of this Notice:

    1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a regulation 28(1) report of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated 1 February 2023, which states that there is or has been a significant risk of supplying water from Ringstead works (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
    2. Consequently, this Notice is served on the Company by the Inspectorate on behalf of the Secretary of State, under regulation 28(4) for the assets listed above, for risks associated with:

    Description of Risk

    Hazard/ Hazardous Event/ Parameter

    Hazard I D

    Increasing risk of a Prescribed Concentration breach.

    Nitrate

    ANH-TSED-A012-TR0908

    Table 2: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.

    1. The Company are required to satisfy the following requirements.

    The date given is that until or by which the requirements must be maintained or satisfied, as appropriate.

    Requirements:

    (a) To maintain the following measures for the period specified in each case:

    1. Regularly review and update groundwater risk assessments.
      Date: Ongoing for the duration of this Notice.
    2. Regularly review and update nitrate exceedance prediction graphs as part of the Regulation 27 risk assessment for the supply system supplied by Ringstead works, in line with the Drinking Water Safety Planning approach, and ensure that Regulation 28 risk assessment reports are regularly reviewed and provided to the Inspectorate.
      Date: Ongoing for the duration of this Notice.
    3. Continue to optimise the existing blending option of the higher nitrate sources with the lower nitrate sources at Ringstead works, to ensure compliance with the Regulations, until the completion of the additional control measures.
      Date: Ongoing for the duration of this Notice.
    4. Continue to implement operational and regulatory monitoring for nitrate for the raw water and final water at Ringstead works and in the downstream Public Water Supply Zone.
      Date: Ongoing for the duration of this Notice.
    5. Investigate exceedances of the nitrate parameter in line with company procedures.
      Date: Ongoing for the duration of this Notice.
    6. Report all exceedances of the nitrate parameter to the Local Authority and Health Protection team and agree further additional steps to protect public health as appropriate.
      Date: Ongoing for the duration of this Notice.
    7. Report all regulatory exceedances of the standards for the nitrate parameter to the Inspectorate, as part of the current monthly exception reporting process.
      Date: Ongoing for the duration of this Notice.
    8. Continue to implement enhanced monitoring strategy for the nitrate parameter, which shall include the monitoring of all high-risk water sources and associated final waters on a weekly basis to supplement the current regulatory treated water monitoring strategy.
      Date: Ongoing for the duration of this Notice.
    9. Continue to support any voluntary initiatives to influence nitrate usage in the groundwater catchments upstream of the Sedgeford catchments, taking a risk-based approach. In particular engage with and provide data to the Environment Agency and other relevant stakeholders as required on a regular basis.
      Date: Ongoing for the duration of this Notice.

    (b) To review, revise or make operational the following measures, by the dates specified in each case:

    1. Complete the design, planning and procurement arrangements to provide an ion exchange plant at Ringstead works.
      Date: 31 December 2027.
    2. Complete the construction, installation and commissioning of an ion exchange plant at Ringstead works, as designed in measure b(1).
      Date: 31 December 2028.

    (c) To audit whether the measures have been effective by the following means:

    1. Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
      Date: 31 March 2024
    2. Implement, and keep under continuous review, the audit strategy defined in measure (c)1.
      Date: Following completion of measure (c)1. onwards.

    (d) Not to supply water for regulation 4(1) purposes from Ringstead works, or not to so supply unless the specified conditions below are satisfied:

    1. Not applicable.

    (e) To provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risks:

    1. Provide a progress report annually.
      Date: by 31 January each year.
    2. Provide a report to confirm the completion of the design, planning and procurement arrangements of the ion exchange plant at Ringstead works, as specified in measure b(1).
      Date: 31 January 2028.
    3. Provide a report to confirm the completion of the construction, installation and commissioning of the ion exchange plant at Ringstead works, as specified in measure b(2).
      Date: 31 January 2029.
    4. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
      Date: 30 April 2024
    5. Submit any revisions of the audit strategy produced under measure (c)2.
      Date: Within 1 month of a revision
    6. Submit a report in the event that any completed measures of this Notice need to be altered in any way, for any reason.
      Date: Ongoing for the duration of this Notice
    7. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
      Date: 31 January 2030.

    Further Details of this Notice:

    1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
    2. Under regulation 28(6) the Inspectorate, on behalf of the Secretary of State, may by notice served on the Company, revoke or vary this Notice.
    3. Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991 (as amended).

    Signed

    Nicholas Adjei
    Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
    24 January 2024
    Reference: ANH-2023-00011

    HDC (Hafren Dyfrdwy)

    Report Data Range: For the whole year 2021

    Table 1: Quality of water leaving service treatment works – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    Nitrite (Total)

    A013B

    0.1 mg NO2/l

    42

    0

    <0.005

    <0.013

    0

    Totals

    42

    0

    Table 2: Quality of water leaving service treatment works – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    952

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    952

    0

    0

    0

    0

    Totals

    1,904

    0

    Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    952

    N/A

    0

    3

    Residual Disinfectant – Free

    C009

    No abnormal change

    952

    N/A

    0.2

    0.71

    Turbidity – Indicator

    A002A

    1 NTU

    952

    0

    <0.12

    <0.24

    Totals

    2,856

    0

    Table 4: Quality of water leaving service reservoirs – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of reservoirs failing standard

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    4,215

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    4,215

    4

    0

    0

    0

    Totals:

    8,430

    4

    Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    4,215

    N/A

    0

    63

    Residual Disinfectant – Free

    C009

    No abnormal change

    4,215

    N/A

    0.05

    0.58

    Totals:

    8,430

    0

    Table 6: Quality of water leaving bulk supply points – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply point with failures

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    42

    0

    <0.24

    <0.3

    0

    Benzene (Total)

    F002

    1 µg/l

    42

    0

    <0.06

    <0.12

    0

    Boron

    D005A

    1 mg B/l

    42

    0

    <0.011

    <0.031

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    41

    0

    <3.6

    <3.6

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    42

    0

    <0.08

    <0.08

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    42

    0

    <0.034

    <0.034

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    16

    0

    0

    0.006

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    16

    0

    <0.009

    <0.009

    0

    Pesticides 2 4-DB

    P082

    0.1 µg/l

    16

    0

    <0.016

    <0.016

    0

    Pesticides 2,3,6-Tba

    P074

    0.1 µg/l

    16

    0

    <0.027

    <0.027

    0

    Pesticides Aldrin

    P002

    0.03 µg/l

    16

    0

    <0.003

    <0.003

    0

    Pesticides Asulam

    P133

    0.1 µg/l

    16

    0

    <0.013

    <0.013

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    16

    0

    <0.011

    <0.011

    0

    Pesticides Azoxystrobin

    P227

    0.1 µg/l

    16

    0

    <0.004

    <0.004

    0

    Pesticides Benazolin (Total)

    P138

    0.1 µg/l

    16

    0

    <0.007

    <0.007

    0

    Pesticides Bentazone

    P006

    0.1 µg/l

    16

    0

    <0.006

    <0.006

    0

    Pesticides Boscalid

    P231

    0.1 µg/l

    16

    0

    <0.007

    <0.007

    0

    Pesticides Bromoxynil

    P008

    0.1 µg/l

    16

    0

    <0.011

    <0.011

    0

    Pesticides Carbendazim (Total)

    P150

    0.1 µg/l

    16

    0

    <0.011

    <0.011

    0

    Pesticides Carbetamide 

    P010

    0.1 µg/l

    16

    0

    <0.012

    <0.012

    0

    Pesticides Chloridazon

    P162

    0.1 µg/l

    16

    0

    <0.004

    <0.004

    0

    Pesticides Chlormequat

    P163

    0.1 µg/l

    16

    0

    <0.003

    <0.003

    0

    Pesticides Chlortoluron

    P014

    0.1 µg/l

    16

    0

    <0.012

    <0.012

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    16

    0

    <0.009

    <0.009

    0

    Pesticides Cyproconazole

    P207

    0.1 µg/l

    16

    0

    <0.007

    <0.007

    0

    Pesticides Diazinon

    P024

    0.1 µg/l

    16

    0

    <0.01

    <0.01

    0

    Pesticides Dicamba

    P025

    0.1 µg/l

    16

    0

    <0.015

    <0.015

    0

    Pesticides Dichlorprop

    P026

    0.1 µg/l

    16

    0

    <0.009

    <0.009

    0

    Pesticides Dieldrin

    P028

    0.03 µg/l

    16

    0

    <0.008

    <0.008

    0

    Pesticides Diflufenican

    P157

    0.1 µg/l

    16

    0

    <0.01

    <0.01

    0

    Pesticides Dimethenamid – P

    P265

    0.1 µg/l

    16

    0

    <0.006

    <0.006

    0

    Pesticides Diuron

    P032

    0.1 µg/l

    16

    0

    <0.013

    <0.013

    0

    Pesticides Epoxyconazole

    P217

    0.1 µg/l

    16

    0

    <0.007

    <0.007

    0

    Pesticides Ethofumersate

    P221

    0.1 µg/l

    16

    0

    <0.015

    <0.015

    0

    Pesticides Flufenacet

    P230

    0.1 µg/l

    16

    0

    <0.005

    <0.005

    0

    Pesticides Fluroxypyr

    P040

    0.1 µg/l

    16

    0

    <0.006

    <0.006

    0

    Pesticides Flusilazole

    P159

    0.1 µg/l

    6

    0

    <0.009

    <0.009

    0

    Pesticides Flutriafol

    P039

    0.1 µg/l

    16

    0

    <0.015

    <0.015

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    16

    0

    <0.015

    <0.03

    0

    Pesticides Heptachlor

    P043

    0.03 µg/l

    16

    0

    <0.003

    <0.003

    0

    Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

    P044

    0.03 µg/l

    16

    0

    0

    0

    0

    Pesticides Isoproturon

    P048

    0.1 µg/l

    16

    0

    <0.011

    <0.011

    0

    Pesticides Linuron

    P051

    0.1 µg/l

    16

    0

    <0.012

    <0.012

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    16

    0

    <0.006

    <0.006

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    16

    0

    <0.005

    <0.005

    0

    Pesticides Metalaxyl

    P209

    0.1 µg/l

    16

    0

    <0.007

    <0.007

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    16

    0

    <0.006

    <0.006

    0

    Pesticides Metamitron

    P194

    0.1 µg/l

    16

    0

    <0.012

    <0.012

    0

    Pesticides Metazachlor

    P203

    0.1 µg/l 

    16

    0

    <0.011

    <0.011

    0

    Pesticides Metribuzin

    P152

    0.1 µg/l

    16

    0

    <0.004

    <0.004

    0

    Pesticides Oxadixyl

    P154

    0.1 µg/l

    16

    0

    <0.004

    <0.004

    0

    Pesticides Pendimethalin

    P118

    0.1 µg/l

    16

    0

    <0.012

    <0.012

    0

    Pesticides Propiconazole

    P068

    0.1 µg/l

    16

    0

    <0.014

    <0.014

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    16

    0

    <0.011

    <0.011

    0

    Pesticides Prosulfocarb

    P243

    0.1 µg/l

    16

    0

    <0.005

    <0.005

    0

    Pesticides Quinmerac

    P224

    0.1 µg/l

    16

    0

    <0.009

    <0.009

    0

    Pesticides Simazine

    P073

    0.1 µg/l

    16

    0

    <0.011

    <0.011

    0

    Pesticides Tebuconazole

    P177

    0.1 µg/l

    16

    0

    <0.006

    <0.006

    0

    Pesticides Terbutryn

    P077

    0.1 µg/l

    16

    0

    <0.009

    <0.009

    0

    Pesticides Triadimefon

    P078

    0.1 µg/l

    16

    0

    <0.012

    <0.012

    0

    Pesticides Tri-allate

    P079

    0.1 µg/l

    16

    0

    <0.003

    <0.003

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    16

    0

    <0.011

    <0.011

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    42

    0

    0

    0

    0

    Totals

    1,179

    0

    Table 7: Quality of water leaving bulk supply points – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply points with failures

    Tetrachloromethane (Total)

    D008

    3 µg/l

    42

    0

    <0.19

    <0.2

    0

    Totals

    42

    0

    Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Chloride

    D002A

    250 mg Cl/l

    42

    0

    8.7

    16.1

    Clostridium Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    42

    0

    0

    0

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    255

    0

    85.312

    279.2

    Sulphate

    A007

    250 mg SO4/l

    42

    0

    6.4

    37.7

    Total Organic Carbon

    A017

    No abnormal change

    42

    N/A

    <0.8

    2.1

    Totals

    423

    0

    Table 9: Quality of water at consumer’s tap (zones) – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of zones failing standard

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    27

    0

    <0.24

    <0.3

    0

    Antimony

    B008A

    5 µg Sb/l

    107

    0

    <0.04

    <0.3

    0

    Arsenic (Total)

    B001A

    10 µg As/l

    107

    0

    0.09

    1.38

    0

    Benzene (Total)

    F002

    1 µg/l

    27

    0

    <0.06

    <0.12

    0

    Benzo[a]Pyrene (Total)

    D007

    0.01 µg/l

    107

    0

    <0.00074

    <0.001

    0

    Boron

    D005A

    1 mg B/l

    27

    0

    <0.011

    <0.031

    0

    Bromate

    F003

    10 µg BrO3/l

    107

    0

    <0.53

    <1.9652

    0

    Cadmium (Total)

    B002

    5 µg Cd/l

    107

    0

    <0.02

    0.15

    0

    Chromium (Total)

    B004

    50 µg Cr/l

    107

    0

    <0.3

    <2.1

    0

    Copper (Total)

    A024A

    2 mg Cu/l

    107

    0

    <0.0014

    0.758864

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    27

    0

    <3.6

    <3.6

    0

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    624

    0

    0

    0

    0

    Enterococci (Confirmed)

    C003

    0 number/100 ml

    107

    0

    0

    0

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    27

    0

    <0.08

    0.11

    0

    Lead (10 – will apply 25.12.2013)

    B007B

    10 µg Pb/l

    107

    0

    <0.13

    4.4252

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    27

    0

    <0.034

    <0.034

    0

    Nickel (Total) 

    B006A 

    20 µg Ni/l

    107

    0

    <0.5

    5.268

    0

    Nitrate (Total)

    A012

    50 mg NO3/l

    107

    0

    0.7548

    29.348

    0

    Nitrite – Consumer’s Taps

    A013A

    0.5 mg NO2/l

    107

    0

    <0.005

    <0.013

    0

    Nitrite/Nitrate formula

    A013C

    1 mg/l

    107

    0

    <0.02

    0.5884

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    27

    0

    0

    0.012

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    27

    0

    <0.009

    0.009

    0

    Pesticides 2 4-DB

    P082

    0.1 µg/l

    27

    0

    <0.016

    <0.016

    0

    Pesticides 2,3,6-Tba

    P074

    0.1 µg/l

    27

    0

    <0.027

    <0.027

    0

    Pesticides Aldrin

    P002

    0.03 µg/l

    27

    0

    <0.003

    <0.003

    0

    Pesticides Asulam

    P133

    0.1 µg/l

    27

    0

    <0.013

    <0.013

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    27

    0

    <0.011

    <0.011

    0

    Pesticides Azoxystrobin

    P227

    0.1 µg/l

    27

    0

    <0.004

    <0.004

    0

    Pesticides Benazolin (Total)

    P138

    0.1 µg/l

    27

    0

    <0.007

    <0.007

    0

    Pesticides Bentazone

    P006

    0.1 µg/l

    27

    0

    <0.006

    <0.006

    0

    Pesticides Boscalid

    P231

    0.1 µg/l

    27

    0

    <0.007

    <0.007

    0

    Pesticides Bromoxynil

    P008

    0.1 µg/l

    27

    0

    <0.011

    <0.011

    0

    Pesticides Carbendazim (Total)

    P150

    0.1 µg/l

    27

    0

    <0.011

    <0.011

    0

    Pesticides Carbetamide 

    P010

    0.1 µg/l

    27

    0

    <0.012

    <0.012

    0

    Pesticides Chloridazon

    P162

    0.1 µg/l

    27

    0

    <0.004

    <0.004

    0

    Pesticides Chlormequat

    P163

    0.1 µg/l

    27

    0

    <0.003

    0.009

    0

    Pesticides Chlortoluron

    P014

    0.1 µg/l

    27

    0

    <0.012

    <0.012

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    27

    0

    <0.009

    <0.009

    0

    Pesticides Cyproconazole

    P207

    0.1 µg/l

    27

    0

    <0.007

    <0.007

    0

    Pesticides Diazinon

    P024

    0.1 µg/l

    27

    0

    <0.01

    <0.01

    0

    Pesticides Dicamba

    P025

    0.1 µg/l

    27

    0

    <0.015

    <0.015

    0

    Pesticides Dichlorprop

    P026

    0.1 µg/l

    27

    0

    <0.009

    <0.009

    0

    Pesticides Dieldrin

    P028

    0.03 µg/l

    27

    0

    <0.008

    <0.008

    0

    Pesticides Diflufenican

    P157

    0.1 µg/l

    27

    0

    <0.01

    <0.01

    0

    Pesticides Dimethenamid – P

    P265

    0.1 µg/l

    27

    0

    <0.006

    <0.006

    0

    Pesticides Diuron

    P032

    0.1 µg/l

    27

    0

    <0.013

    <0.013

    0

    Pesticides Epoxyconazole

    P217

    0.1 µg/l

    27

    0

    <0.007

    <0.007

    0

    Pesticides Ethofumersate

    P221

    0.1 µg/l

    27

    0

    <0.015

    <0.015

    0

    Pesticides Flufenacet

    P230

    0.1 µg/l

    27

    0

    <0.005

    <0.005

    0

    Pesticides Fluroxypyr

    P040

    0.1 µg/l

    27

    0

    <0.006

    <0.006

    0

    Pesticides Flusilazole

    P159

    0.1 µg/l

    9

    0

    <0.009

    <0.009

    0

    Pesticides Flutriafol

    P039

    0.1 µg/l

    27

    0

    <0.015

    <0.015

    0

    Pesticides Fosthiazate

    P254

    0.1 µg/l

    27

    0

    <0.012

    <0.012

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    27

    0

    <0.015

    <0.03

    0

    Pesticides Heptachlor

    P043

    0.03 µg/l

    27

    0

    <0.003

    <0.003

    0

    Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

    P044

    0.03 µg/l

    27

    0

    0

    0

    0

    Pesticides Isoproturon

    P048

    0.1 µg/l

    27

    0

    <0.011

    <0.011

    0

    Pesticides Linuron

    P051

    0.1 µg/l

    27

    0

    <0.012

    <0.012

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    27

    0

    <0.006

    <0.006

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    27

    0

    <0.005

    <0.005

    0

    Pesticides Metalaxyl

    P209

    0.1 µg/l

    27

    0

    <0.007

    <0.007

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    27

    0

    <0.006

    <0.006

    0

    Pesticides Metamitron

    P194

    0.1 µg/l

    27

    0

    <0.012

    <0.012

    0

    Pesticides Metazachlor

    P203

    0.1 µg/l 

    27

    0

    <0.011

    <0.011

    0

    Pesticides Metribuzin

    P152

    0.1 µg/l

    27

    0

    <0.004

    <0.004

    0

    Pesticides Oxadixyl

    P154

    0.1 µg/l

    27

    0

    <0.004

    <0.004

    0

    Pesticides Pendimethalin

    P118

    0.1 µg/l

    27

    0

    <0.012

    <0.012

    0

    Pesticides Propiconazole

    P068

    0.1 µg/l

    27

    0

    <0.014

    <0.014

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    27

    0

    <0.011

    <0.011

    0

    Pesticides Prosulfocarb

    P243

    0.1 µg/l

    27

    0

    <0.005

    <0.005

    0

    Pesticides Quinmerac

    P244

    0.1 µg/l

    27

    0

    <0.009

    <0.009

    0

    Pesticides Simazine

    P073

    0.1 µg/l

    27

    0

    <0.011

    <0.011

    0

    Pesticides Tebuconazole

    P177

    0.1 µg/l

    27

    0

    <0.006

    <0.006

    0

    Pesticides Terbutryn

    P077

    0.1 µg/l

    27

    0

    <0.009

    <0.009

    0

    Pesticides Triadimefon

    P078

    0.1 µg/l

    27

    0

    <0.012

    <0.012

    0

    Pesticides Tri-allate

    P079

    0.1 µg/l

    27

    0

    <0.003

    <0.003

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    27

    0

    <0.011

    <0.011

    0

    Polycyclic Aromatic Hydrocarbons (Total by Calculation)

    B011F

    0.1 µg/l

    107

    0

    0

    0

    0

    Selenium (Total)

    B009

    10 µg Se/l

    107

    0

    <0.07

    <0.65

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    27

    0

    0

    0

    0

    Trihalomethanes (Total by Calculation)

    D011

    100 µg/l

    107

    0

    0

    83.6172

    0

    Totals

    4,046

    0

    Table 10: Quality of water at consumer’s tap (zones) – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    No. of zones failing standard

    Aluminium (Total)

    A021

    200 µg Al/l

    256

    0

    <14

    42.01

    0

    Colour

    A001

    20 mg/l Pt/Co

    285

    0

    <0.7

    <2.704

    0

    Iron (Total)

    A022

    200 µg Fe/l

    256

    0

    <8

    110

    0

    Manganese (Total)

    A023

    50 µg Mn/l

    256

    0

    <0.7

    3.415

    0

    Odour

    A003

    0 Dilution number at 25°C

    286

    0

    0

    0

    0

    Sodium (Total)

    A009

    200 mg Na/l

    107

    0

    4.26

    56.992

    0

    Taste (Taste Quant)

    A004

    0 Dilution number at 25°C

    286

    0

    0

    0

    0

    Tetrachloromethane (Total)

    D008

    3 µg/l

    27

    0

    <0.19

    <0.2

    0

    Turbidity

    A002

    4 NTU

    285

    0

    <0.12

    <0.24

    0

    Totals

    2,044

    0

    Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Ammonium (Total)

    A014

    0.5 mg NH4/l

    285

    0

    <0.029

    <0.064

    Chloride

    D002A

    250 mg Cl/l

    27

    0

    4.7

    121.1

    Clostridium Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    60

    0

    0

    0

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    624

    1

    0

    0

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    286

    N/A

    0

    66

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    62

    0

    45.1

    621

    Gross Alpha

    F004

    0.1 Bq/l

    1

    0

    <0.034

    <0.034

    Gross Beta

    F005

    1 Bq/l

    1

    0

    <0.018

    <0.018

    Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

    A006

    6.5 – 9.5 pH Value

    285

    0

    6.6874

    8.5342

    Residual Disinfectant – Free

    C009

    No abnormal change

    624

    N/A

    0.0225

    0.66

    Sulphate

    A007

    250 mg SO4/l

    27

    0

    6

    45.4

    Total Organic Carbon

    A017

    No abnormal change

    27

    N/A

    <0.8

    2.2

    Tritium

    F006

    100 Bq/l

    1

    0

    <3

    <3

    Totals

    2,310

    1

    Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

    Reference: BRL-2021-00003

    Version Number: 5

    Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): South West Water Limited, with registered number 02366665 (hereinafter called ‘the Company’).

    Assets Affected:

    Priority zones for 2024/5:

    • Z407 Clifton, Horefield, Redland and Kingsdown
    • Z408 Bedminster
    • Z411 Eastville, Easton, Netham and St Philips
    • Z414 Whitchurch, Hengrove, Knowle and Knowle Park
    • Z421 Wells, Glastonbury, Street and Baltonsborough
    • Z420 Cheddar, Wedmore, Brent Knoll and Burnham-On-Sea
    • Z409 Long Ashton, Failand, Bishopsworth and Dundry
    • Z422 Shepton Mallet, Pilton, Oakhill, Wookey Hole and Shipham

    Details of this Notice:

    1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a set of regulation 28(1) reports of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated between 15 June and 14 July 2022, which state that there is or has been a significant risk of supplying water from water supply zones (and associated assets as applicable) that could be unwholesome.
    2. Consequently, this Notice is served on the Company by the Inspectorate on behalf of the Secretary of State, under regulation 28(4) for the assets listed above, for risks associated with:

    Description of Risk

    Hazard/ Hazardous Event/ Parameter

    Hazard I D

    Consumer acceptability (discolouration)  

    Aluminium 

    Multiple risk assessment reports (Annex 1). For example:

    Z407Hazard0004

    Consumer acceptability (discolouration)  

    Iron  

    Z407Hazard0019

    Consumer acceptability (discolouration)  

    Manganese

    Z407Hazard0020

    Consumer acceptability (discolouration)  

    Turbidity  

    Z407Hazard0039

    Consumer acceptability (discolouration)  

    Discolouration

    Z407Hazard0040

    Table 1: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.

    1. The Company are required to satisfy the following requirements.

    The date given is that until or by which the requirements must be maintained or satisfied, as appropriate.

    Requirements:

    (a) To maintain the following measures for the period specified in each case:

    1. Undertake regulatory and risk-based enhanced monitoring as defined within section (c)1 from treatment works, reservoirs and any water supply zones identified as being at risk of discolouration, including the zones listed within this Notice. 
      Date: Ongoing for the duration of this notice
    2. Investigate any failure of a discolouration parameter (Aluminium, Iron, Manganese or Turbidity) and determine root cause.
      Date: Ongoing for the duration of this notice
    3. Record and monitor customer contacts in appropriate detail and along with water quality data, keep under review to inform the forward programme of work.
      Date: Ongoing for the duration of this notice
    4. Deliver a programme of proactive investigation and evidence-based intervention on the distribution network, to manage discolouration risks.
      Date: Ongoing for the duration of this notice
    5. Optimisation of existing treatment processes with particular regard to the removal of Aluminium, Iron and Manganese. 
      Date: Ongoing for the duration of this notice

    (b) To review, revise or make operational the following measures, by the dates specified in each case:

    1. Review and revise as appropriate the current discolouration strategy to reduce the risk of discoloured water in water supply zones. To include:
      • Treatment works
      • Service Reservoirs
      • Trunk mains
      • Zonal network
        Date: Complete
    1. Review and revise as appropriate the current risk assessment methodology for discolouration, consumer contacts, and consumer acceptability in water supply zones. Using this methodology carry out an annual review for all water supply zones to identify and prioritise high-risk zones for further investigation and input into regulation 27 risk assessments to allow for revision of the notice where appropriate. To include:
      • Treatment works
      • Service Reservoirs
      • Trunk mains
      • Zonal network
        Date: Annually for the duration of this notice
    1. For water supply zones identified in (b)2 carry out investigations to identify and evidence the most appropriate interventions to reduce discolouration contacts.
      Date: 31 December 2021 and ongoing for the duration of the notice
    2. Develop and keep under review a dynamic programme of work to reduce discolouration contacts in water supply zones listed, utilising the information gathered in (b)3.
      Date: 31 December 2021 and ongoing for the duration of the notice
    3. Implement the programme of work as identified in (b)3 and (b)4, to achieve the following:
      • By 2025 a reduction in consumer contacts for discolouration (black/brown/orange) to below the target of 0.8 per 1000 population for the zones listed and to reach an overall company contact rate for the defined company Outcome Delivery Incentives (ODI) for Appearance: 0.43 per 1000 population.
        Date: 31 December 2021 and ongoing for the duration of this notice

    (c) To audit whether the measures have been effective by the following means:

    1. Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
      Date: Complete
    2. Implement, and keep under continuous review, the audit strategy defined in measure (c)1.
      Date: Following the completion of measure (c)1, onwards

    (d) Not to supply water for regulation 4(1) purposes from water supply zones, or not to so supply unless the specified conditions below are satisfied:

    1. Not applicable.

    (e) To provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risks:

    1. Provide a progress report annually.
      Date: by 31 January, each year
    2. Provide the updated discolouration strategy, as stipulated in (b)1.
      Date: Complete
    3. Provide a list of priority zones on an annual basis as indicated in section (b)2.
      Date: Annually by 30 April
    4. Provide a report on the investigations and the identified interventions to reduce discolouration contacts in the zones, as specified in (b)3.
      Date: Annually by 30 April
    5. Provide a report on the dynamic programme of work for each zone listed, as specified in (b)4.
      Date: Annually by 30 April
    6. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
      Date: Complete
    7. Submit any revisions of the audit strategy produced under measure (c)2.
      Date: Within 1 month of a revision
    8. Submit a report in the event that any completed measures of this Notice need to be altered in any way, for any reason.
      Date: Ongoing for the duration of this Notice
    9. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
      Date: 30 April 2026

    Further Details of this Notice:

    1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
    2. Under regulation 28(6) the Inspectorate, on behalf of the Secretary of State, may by notice served on the Company, revoke or vary this Notice.
    3. Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991 (as amended).

    Signed

    Nicholas Adjei
    Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
    6 August 2024
    Reference: BRL-2021-00003 (v5)

     

    ISC (Isles of Scilly)

    Report Data Range: For the whole year 2021

    Table 1: Quality of water leaving service treatment works – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    Nitrite (Total)

    A013B

    0.1 mg NO2/l

    29

    0

    <0.015

    0.068

    0

    Totals

    29

    0

    Table 2: Quality of water leaving service treatment works – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    249

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    249

    3

    0

    7

    3

    Totals

    498

    3

    Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    29

    N/A

    0

    173

    Residual Disinfectant – Free

    C009

    No abnormal change

    249

    N/A

    0

    1.45

    Residual Disinfectant – Total

    C010

    No abnormal change

    249

    N/A

    0

    1.48

    Turbidity – Indicator

    A002A

    1 NTU

    249

    0

    0.01

    0.35

    Totals

    996

    0

    Table 4: Quality of water leaving service reservoirs – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of reservoirs failing standard

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    465

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    465

    2

    0

    0

    0

    Totals:

    930

    2

    Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    465

    N/A

    0

    32

    Residual Disinfectant – Free

    C009

    No abnormal change

    465

    N/A

    0

    0.4702

    Residual Disinfectant – Total

    C010

    No abnormal change

    465

    N/A

    0

    0.5434

    Totals:

    1,395

    0

    Table 6: Quality of water leaving bulk supply points – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply point with failures

    Boron

    D005A

    1 mg B/l

    23

    0

    0.00567

    0.465

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    23

    0

    <2.7

    <2.7

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    24

    0

    <0.011

    0.087

    0

    Mercury (Total)

    B005

    1 µg Hg/l 

    23

    0

    <0.04

    <0.04

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    29

    0

    0

    0.001

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    23

    0

    <0.01

    <0.01

    0

    Pesticides 2 4-DB

    P082

    0.1 µg/l

    23

    0

    <0.007

    <0.007

    0

    Pesticides Asulam

    P133

    0.1 µg/l

    23

    0

    <0.012

    <0.048

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    23

    0

    <0.007

    <0.007

    0

    Pesticides Azoxystrobin

    P227

    0.1 µg/l

    23

    0

    <0.005

    <0.005

    0

    Pesticides Bentazone

    P006

    0.1 µg/l

    23

    0

    <0.002

    <0.008

    0

    Pesticides Boscalid

    P231

    0.1 µg/l

    23

    0

    <0.007

    <0.007

    0

    Pesticides Bromoxynil

    P008

    0.1 µg/l

    23

    0

    <0.006

    <0.024

    0

    Pesticides Carbendazim (Total)

    P150

    0.1 µg/l

    23

    0

    <0.003

    <0.003

    0

    Pesticides Chlorpyrifos (Chlorpyriphos Ethyl)

    P017

    0.1 µg/l

    25

    0

    <0.002

    <0.003

    0

    Pesticides Chlortoluron

    P014

    0.1 µg/l

    23

    0

    <0.005

    <0.005

    0

    Pesticides Clopyralid

    P018

    0.1 µg/l

    23

    0

    <0.009

    <0.036

    0

    Pesticides Cyprodinil

    P228

    0.1 µg/l

    26

    0

    <0.01

    <0.012

    0

    Pesticides Cyromazine

    P223

    0.1 µg/l

    23

    0

    <0.012

    <0.012

    0

    Pesticides Diazinon

    P024

    0.1 µg/l

    26

    0

    <0.007

    <0.008

    0

    Pesticides Dicamba

    P025

    0.1 µg/l

    23

    0

    <0.01

    <0.01

    0

    Pesticides Dichlobenil

    P098

    0.1 µg/l

    23

    0

    <0.003

    <0.004

    0

    Pesticides Dichlorprop

    P026

    0.1 µg/l

    23

    0

    <0.009

    <0.009

    0

    Pesticides Dieldrin

    P028

    0.03 µg/l

    26

    0

    <0.004

    <0.005

    0

    Pesticides Diflufenican

    P157

    0.1 µg/l

    26

    0

    <0.003

    <0.004

    0

    Pesticides Diuron

    P032

    0.1 µg/l

    23

    0

    <0.007

    <0.007

    0

    Pesticides Epoxyconazole

    P217

    0.1 µg/l

    26

    0

    <0.016

    <0.019

    0

    Pesticides Fenpropimorph

    P037

    0.1 µg/l

    26

    0

    <0.003

    <0.004

    0

    Pesticides Linuron

    P051

    0.1 µg/l

    23

    0

    <0.012

    <0.012

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    23

    0

    <0.006

    <0.006

    0

    Pesticides MCPB

    P055

    0.1 µg/l

    23

    0

    <0.008

    <0.008

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    23

    0

    <0.007

    <0.007

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    16

    0

    <0.001

    <0.003

    0

    Pesticides Metamitron

    P194

    0.1 µg/l 

    23

    0

    <0.01

    <0.01

    0

    Pesticides Pendimethalin

    P118

    0.1 µg/l

    26

    0

    <0.003

    <0.004

    0

    Pesticides Pentachlorophenol

    P060

    0.1 µg/l

    23

    0

    <0.007

    <0.007

    0

    Pesticides Picloram (Total)

    P122

    0.1 µg/l

    23

    0

    <0.004

    <0.016

    0

    Pesticides Propamocarb

    P238

    0.1 µg/l

    23

    0

    <0.009

    <0.009

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    23

    0

    <0.005

    <0.005

    0

    Pesticides Quinmerac

    P224

    0.1 µg/l

    23

    0

    <0.002

    <0.025

    0

    Pesticides Simazine

    P073

    0.1 µg/l

    23

    0

    <0.007

    <0.007

    0

    Pesticides Tebuconazole

    P177

    0.1 µg/l

    23

    0

    <0.007

    <0.007

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    23

    0

    <0.004

    <0.016

    0

    Radon

    F031

    100 Bq/l

    23

    18

    13.6

    858

    7

    Totals

    1,130

    18

    Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Chloride

    D002A

    250 mg Cl/l

    24

    4

    4.4

    493

    Clostridium Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    23

    0

    0

    0

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    24

    0

    65.2

    1690

    Gross Alpha

    F004

    0.1 Bq/l

    24

    20

    <0.02

    1.852

    Gross Beta

    F005

    1 Bq/l

    24

    2

    <0.054

    2.222

    Sulphate

    A007

    250 mg SO4/l

    24

    0

    <2.4

    61.9

    Total Organic Carbon

    A017

    No abnormal change

    24

    N/A

    <0.42

    11.56

    Tritium

    F006

    100 Bq/l

    12

    0

    <5.6

    8.03

    Totals

    179

    26

    Table 9: Quality of water at consumer’s tap (zones) – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply point with failures

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    15

    0

    <0.2

    <0.2

    0

    Antimony

    B008A

    5 µg Sb/l

    15

    0

    <0.05

    <0.5

    0

    Arsenic (Total)

    B001A

    10 µg As/l

    15

    0

    <3.1

    9.3

    0

    Benzene (Total)

    F002

    1 µg/l

    15

    0

    <0.2

    <0.2

    0

    Benzo[a]Pyrene (Total)

    D007

    0.01 µg/l

    15

    0

    <0.0005

    <0.001

    0

    Bromate

    F003

    10 µg BrO3/l

    12

    0

    <0.15

    1.8

    0

    Cadmium (Total)

    B002

    5 µg Cd/l

    15

    0

    <0.06

    <0.6

    0

    Chromium (Total)

    B004

    50 µg Cr/l

    15

    0

    <0.8

    <8

    0

    Copper (Total)

    A024A

    2 mg Cu/l

    13

    0

    0.0112

    0.754

    0

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    36

    0

    0

    0

    0

    Enterococci (Confirmed)

    C003

    0 number/100 ml

    15

    0

    0

    0

    0

    Lead (10 – will apply 25.12.2013)

    B007B

    10 µg Pb/l

    13

    0

    0.386

    2.08

    0

    Nickel (Total)

    B006A

    20 µg Ni/l

    13

    0

    <3.3

    <16.5

    0

    Nitrate (Total)

    A012

    50 mg NO3/l

    14

    0

    <1.6

    42.71

    0

    Nitrite – Consumer’s Taps

    A013A

    0.5 mg NO2/l

    14

    0

    <0.015

    <0.015

    0

    Nitrite/Nitrate formula

    A013C

    1 mg/l

    14

    0

    0

    0.85

    0

    Polycyclic Aromatic Hydrocarbons (Total by Calculation)

    B011F

    0.1 µg/l

    15

    0

    0

    0.001

    0

    Selenium (Total)

    B009

    10 µg Se/l

    15

    0

    <0.52

    5.6

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    15

    0

    0

    0

    0

    Trihalomethanes (Total by Calculation)

    D011

    100 µg/l

    15

    1

    0

    106.3

    1

    Totals

    309

    1

    Table 10: Quality of water at consumer’s tap (zones) – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    No. of zones failing standard

    Aluminium (Total)

    A021

    200 µg Al/l

    15

    0

    15.6

    115

    0

    Colour

    A001

    20 mg/l Pt/Co

    15

    0

    <0.8

    11.4

    0

    Iron (Total)

    A022

    200 µg Fe/l

    15

    0

    7.91

    <76

    0

    Manganese (Total)

    A023

    50 µg Mn/l

    15

    1

    0.66

    324

    1

    Odour

    A003

    0 Dilution number at 25°C

    15

    0

    0

    0

    0

    Sodium (Total)

    A009

    200 mg Na/l

    15

    0

    <1

    180

    0

    Taste (Taste Quant)

    A004

    0 Dilution number at 25°C

    15

    2

    0

    5

    2

    Tetrachloromethane (Total)

    D008

    3 µg/l

    15

    0

    <0.2

    <0.2

    0

    Turbidity

    A002

    4 NTU

    15

    0

    0.071

    0.28

    0

    Totals

    135

    3

    Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Ammonium (Total)

    A014

    0.5 mg NH4/l

    14

    0

    0.003

    0.14

    Chloride

    D002A

    250 mg Cl/l

    1

    0

    28

    28

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    36

    0

    0

    0

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    36

    N/A

    0

    100

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    1

    0

    1450

    1450

    Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

    A006

    6.5 – 9.5 pH Value

    15

    1

    6.3

    7.8

    Residual Disinfectant – Free

    C009

    No abnormal change

    36

    N/A

    0

    0.38

    Residual Disinfectant – Total

    C010

    No abnormal change

    36

    N/A

    0

    0.47

    Totals

    175

    1

    Report Data Range: For the whole year 2021

    Table 1: Quality of water leaving service treatment works – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    Nitrite (Total)

    A013B

    0.1 mg NO2/l

    2,049

    0

    <0.01

    <0.01

    0

    Totals

    2,049

    0

    Table 2: Quality of water leaving service treatment works – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of works with failures

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    2,049

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    2,049

    0

    0

    0

    0

    Totals

    4,098

    0

    Table 3: Quality of water leaving service treatment works – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    2,049

    N/A

    0

    2

    Residual Disinfectant – Total

    C010

    No abnormal change

    2,049

    N/A

    0.215

    1.14

    Turbidity – Indicator

    A002A

    1 NTU

    2,049

    0

    <0.06

    0.2

    Totals

    6,147

    0

    Table 4: Quality of water leaving service reservoirs – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of reservoirs failing standard

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    1,808

    0

    0

    0

    0

    Total Coliforms (Confirmed)

    C001

    0 number/100 ml

    1,808

    0

    0

    0

    0

    Totals:

    3,616

    0

    Table 5: Quality of water leaving service reservoirs – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    1,808

    N/A

    0

    772

    Residual Disinfectant – Free

    C009

    No abnormal change

    1,807

    N/A

    <0.04

    0.82

    Totals:

    3,615

    0

    Table 6: Quality of water leaving bulk supply points – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of supply point with failures

    Bromate

    F003

    10 µg BrO3/l

    53

    0

    <0.8

    <0.8

    0

    Cyanide (Total)

    B003

    50 µg CN/l

    53

    0

    <2

    8.3

    0

    Fluoride (Total)

    A027

    1.5 mg F/l

    53

    0

    <0.06

    0.21

    0

    Mercury (Total)

    B005

    1 µg Hg/l

    53

    0

    <0.04

    0.05

    0

    Pesticides (Total by Calculation)

    B010

    0.5 µg/l

    53

    0

    0

    0.06

    0

    Pesticides 2 4-D

    P020

    0.1 µg/l

    8

    0

    <0.003

    <0.003

    0

    Pesticides Aldrin

    P002

    0.03 µg/l

    53

    0

    <0.007

    <0.007

    0

    Pesticides Atrazine

    P004

    0.1 µg/l

    53

    0

    <0.004

    0.035

    0

    Pesticides Azoxystrobin

    P227

    0.1 µg/l

    53

    0

    <0.014

    <0.014

    0

    Pesticides Bentazone

    P231

    0.1 µg/l

    53

    0

    <0.01

    <0.01

    0

    Pesticides Carbendazim (Total)

    P150

    0.1 µg/l

    53

    0

    <0.004

    <0.004

    0

    Pesticides Carbetamide

    P010

    0.1 µg/l

    53

    0

    <0.004

    0.006

    0

    Pesticides Chlortoluron

    P014

    0.1 µg/l

    53

    0

    <0.003

    <0.003

    0

    Pesticides Clopyralid

    P018

    0.03 µg/l

    8

    0

    0.013

    0.021

    0

    Pesticides Dieldrin

    P028

    0.03 µg/l

    53

    0

    <0.007

    <0.007

    0

    Pesticides Diflufenican

    P157

    0.1 µg/l

    53

    0

    <0.005

    <0.005

    0

    Pesticides Dimethenamid

    P245

    0.1 µg/l

    53

    0

    <0.005

    <0.005

    0

    Pesticides Diuron

    P032

    0.1 µg/l

    53

    0

    <0.006

    <0.006

    0

    Pesticides Epoxyconazole

    P217

    0.1 µg/l

    53

    0

    <0.007

    <0.007

    0

    Pesticides Flufenacet

    P230

    0.1 µg/l

    53

    0

    <0.006

    0.013

    0

    Pesticides Fluroxypyr

    P040

    0.1 µg/l

    8

    0

    <0.003

    <0.003

    0

    Pesticides Flutriafol

    P039

    0.1 µg/l

    53

    0

    <0.004

    <0.004

    0

    Pesticides Glyphosate

    P042

    0.1 µg/l

    8

    0

    <0.005

    <0.005

    0

    Pesticides Heptachlor

    P043

    0.03 µg/l

    53

    0

    <0.008

    <0.008

    0

    Pesticides Heptachlor Epoxide – Total (Trans, CIS) (Heptachlor Epoxide)

    P044

    0.03 µg/l

    53

    0

    <0.005

    <0.005

    0

    Pesticides Isoproturon

    P048

    0.1 µg/l

    53

    0

    <0.005

    <0.005

    0

    Pesticides MCPA 4-chloro-o-tolyloxyacetic acid

    P054

    0.1 µg/l

    8

    0

    <0.004

    <0.004

    0

    Pesticides MCPP (Mecoprop)

    P053

    0.1 µg/l

    8

    0

    <0.002

    <0.002

    0

    Pesticides Metaldehyde

    P226

    0.1 µg/l 

    21

    0

    <0.01

    0.02

    0

    Pesticides Metazachlor

    P203

    0.1 µg/l

    53

    0

    <0.002

    <0.002

    0

    Pesticides Methabenzthiazuron

    P167

    0.1 µg/l

    53

    0

    <0.002

    <0.002

    0

    Pesticides Pendimethalin

    P118

    0.1 µg/l

    53

    0

    <0.009

    <0.009

    0

    Pesticides Picloram (Total)

    P122

    0.1 µg/l

    45

    0

    <0.004

    0.012

    0

    Pesticides Propyzamide

    P071

    0.1 µg/l

    53

    0

    <0.001

    0.012

    0

    Pesticides Prosulfocarb

    P243

    0.1 µg/l

    53

    0

    <0.001

    <0.001

    0

    Pesticides Quinmerac

    P244

    0.1 µg/l

    8

    0

    <0.004

    <0.02

    0

    Pesticides Simazine

    P073

    0.1 µg/l

    53

    0

    <0.007

    0.016

    0

    Pesticides Tebuconazole

    P177

    0.1 µg/l

    53

    0

    <0.004

    <0.004

    0

    Pesticides Tri-allate

    P079

    0.1 µg/l

    53

    0

    <0.01

    <0.01

    0

    Pesticides Triclopyr

    P131

    0.1 µg/l

    8

    0

    <0.003

    <0.003

    0

    Totals

    1,720

    0

    Table 8: Quality of water leaving bulk supply points – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Chloride

    D002A

    250 mg Cl/l

    53

    0

    22.7

    50.2

    Clostridium Perfringens (Sulphite-reducing Clostridia) (Confirmed)

    C004A

    0 number/100 ml

    53

    0

    0

    0

    Conductivity (Electrical Conductivity)

    D001

    2500 µS/cm at 20°C

    672

    0

    314.73

    572.27

    Gross Alpha

    F004

    0.1 Bq/l

    8

    0

    0.03

    0.09

    Gross Beta

    F005

    1 Bq/l

    8

    0

    <0.28

    <0.28

    Sulphate

    A007

    250 mg SO4/l

    53

    0

    15.2

    93.5

    Total Organic Carbon

    A017

    No abnormal change

    53

    N/A

    0.32

    4.4

    Totals

    900

    0

    Table 9: Quality of water at consumer’s tap (zones) – European Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 Percentile (representing a minimum)

    99 Percentile (representing a maximum)

    No. of zones failing standard

    1 2-Dichloroethane (Total)

    F001

    3 µg/l

    160

    0

    <0.08

    <0.08

    0

    Antimony

    B008A

    5 µg Sb/l

    160

    0

    <0.09

    0.37

    0

    Arsenic (Total)

    B001A

    10 µg As/l

    160

    0

    <0.15

    0.58

    0

    Benzene (Total)

    F002

    1 µg/l

    160

    0

    <0.01

    0.0139

    0

    Benzo[a]Pyrene (Total)

    D007

    0.01 µg/l

    160

    0

    <0.001

    <0.001

    0

    Boron

    D005A

    1 mg B/l

    160

    0

    <0.04

    0.08

    0

    Cadmium (Total)

    B002

    5 µg Cd/l

    160

    0

    <0.06

    0.1639

    0

    Chromium (Total)

    B004

    50 µg Cr/l

    160

    0

    <0.8

    1.2

    0

    Copper (Total)

    A024A

    2 mg Cu/l

    161

    0

    <0.03

    0.267

    0

    E coli (faecal coliforms Confirmed)

    C002

    0 number/100 ml

    1,872

    0

    0

    0

    0

    Enterococci (Confirmed)

    C003

    0 number/100 ml

    160

    0

    0

    0

    0

    Lead (10 – will apply 25.12.2013)

    B007B

    10 µg Pb/l

    160

    0

    <0.3

    5.278

    0

    Nickel (Total) 

    B006A 

    20 µg Ni/l

    160

    1

    0.6

    21.57

    0

    Nitrate (Total)

    A012

    50 mg NO3/l

    696

    0

    3.7

    37.1

    0

    Nitrite – Consumer’s Taps

    A013A

    0.5 mg NO2/l

    696

    0

    <0.01

    0.25721

    0

    Nitrite/Nitrate formula

    A013C

    1 mg/l

    696

    0

    0.1

    0.7

    0

    Polycyclic Aromatic Hydrocarbons (Total by Calculation)

    B011F

    0.1 µg/l

    160

    0

    0

    0

    0

    Selenium (Total)

    B009

    10 µg Se/l

    160

    0

    <0.27

    1.3939

    0

    Trichloroethene & Tetrachloroethene – Sum Of 2 Substances (Total by Calculation)

    D009B

    10 µg/l

    160

    0

    0

    2.2812

    0

    Trihalomethanes (Total by Calculation)

    D011

    100 µg/l

    160

    0

    1.161

    55.463

    0

    Totals

    6,521

    1

    Table 10: Quality of water at consumer’s tap (zones) – National Standards

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests Failed

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    No. of zones failing standard

    Aluminium (Total)

    A021

    200 µg Al/l

    423

    0

    <5

    30.67

    0

    Colour

    A001

    20 mg/l Pt/Co

    696

    0

    <1.6

    4

    0

    Iron (Total)

    A022

    200 µg Fe/l

    564

    0

    <6

    52.7

    0

    Manganese (Total)

    A023

    50 µg Mn/l

    432

    0

    <0.9

    4.5

    0

    Odour

    A003

    0 Dilution number at 25°C

    696

    0

    0

    0

    0

    Sodium (Total)

    A009

    200 mg Na/l

    160

    0

    12

    27.39

    0

    Taste (Taste Quant)

    A004

    0 Dilution number at 25°C

    696

    0

    0

    0

    0

    Tetrachloromethane (Total)

    D008

    3 µg/l

    160

    0

    <0.11

    <0.11

    0

    Turbidity

    A002

    4 NTU

    696

    0

    <0.06

    0.4412

    0

    Totals

    4,532

    0

    Table 11: Quality of water at consumer’s tap (zones) – Additional Monitoring Requirements

    Parameter Name

    Parameter Code

    Prescribed Concentration or Value

    Total Number of Tests

    Tests exceeding specification

    1 percentile (representing a minimum)

    99 percentile (representing a maximum)

    Ammonium (Total)

    A014

    0.5 mg NH4/l

    696

    0

    <0.02

    0.18

    Coliform Bacteria (Indicator)

    C001A

    0 number/100 ml

    1,872

    0

    0

    0

    Colony Counts After 3 Days At 22øc (Colony Counts)

    C007

    No abnormal change

    696

    N/A

    0

    420

    Hydrogen ion (pH) – Indicator (Hydrogen ion) (pH)

    A006

    6.5 – 9.5 pH Value

    696

    0

    7.32

    7.9

    Residual Disinfectant – Total

    C010

    No abnormal change

    1,872

    N/A

    <0.04

    0.84

    Totals

    5,832

    0

    UV disinfection

    Ultraviolet (UV) irradiation is a common method for the disinfection of private supplies. Chlorination may be more suitable for larger supplies where it is necessary to maintain a residual disinfectant during storage and distribution.

    Installation of a UV unit

    There are many UV units on the market and care must be taken when selecting a unit for a private water supply. Units must be designed for drinking water treatment. Where possible validated units are to be recommended. Validated units are tested to ensure that the stated level of disinfection is achieved under normal operating conditions. UV units for ponds and fish tanks are not suitable for use on supplies for human consumption.

    Special lamps are used to generate UV radiation. The lamps are enclosed in a reaction chamber made of stainless steel or plastics. Low pressure mercury lamps are most commonly used. These lamps are similar in design, construction and operation to fluorescent tubes except that they are constructed of UV transparent quartz instead of phosphor coated glass. The optimum operating temperature of the lamp is around 40°C so the lamp is normally separated from the water by a sleeve to prevent cooling by the water.

    The usual UV reactor configuration comprises a quartz sleeved low pressure mercury lamp in direct contact with the water. Water enters the unit and flows along the annular space between the quartz sleeve and the wall of the chamber. Other configurations include lamps separated from the water, for example, those were the lamps are surrounded by bundles of PTFE tubes through which the water flows.

    Disinfection will only be effective provided that a sufficient dose of UV is applied. The dose of UV radiation is expressed as an energy flux, in units of mW.s/cm2 (milliwatt seconds per square centimetre), or more commonly as millijoules per centimeter squared (mJ/cm2) which is the product of the intensity given out by the lamp and the residence time of water in the reactor. The minimum dose required for disinfection depends on several factors, including the susceptibility of microorganisms but is generally taken to be around 40mJ/cm2.

    The clarity of water is usually expressed in terms of the amount of UV light that can pass – its ‘Ultraviolet Transmittance’ (UVT). Minimum UVT values, typically greater than 90-95%, are commonly specified by UV equipment manufacturers/suppliers.

    It is important, to ensure effective disinfection, that both residence time and UV intensity are adequate. Manufacturers’ recommendations must be followed regarding installation, operation and maintenance. In particular, the maximum design flow rate should not be exceeded, lamps should be allowed to reach their operating temperatures before water is passed through the unit and lamps should be cleaned and replaced as recommended. A continuous UV monitor and an alarm or failsafe device is strongly recommended and although not usually fitted as standard on point-of-use units, they are usually available as an extra. Some units incorporate a manual wiper for cleaning whilst others incorporate automatic mechanical cleaning.

    Risk Assessments

    Risk assessments are key to understanding appropriate installation and management of UV systems. Contact your local authority or see our website for further information.

    Find out more

    Testing a UV unit

    UV disinfection efficiency is particularly affected by water quality and flow rate. For UV disinfection be effective the water must first be of good quality and in particular low in turbidity. Unlike chlorination, UV is effective in inactivating Cryptosporidium provided that a sufficient UV dose is applied. However, where Cryptosporidium is likely to be present and its removal is required then pre-filtration capable of achieving a turbidity of less than 1NTU is required prior to UV disinfection. Pre-filtration provides an additional barrier to passage of oocysts into the treated water removes particles that shield microorganisms from the UV light and helps to reduce fouling of the UV lamp. Colour can be removed by activated carbon cartridges or membrane filters to around 20°H or lower. Iron and/or manganese can be removed by oxidation and filtration in proprietary units to around 200 μg/l or 50 μg/l or lower, respectively.

    The usual measure for the suitability of treatment by UV disinfection is UV254 absorbance, which may be measured with online monitors or sampled and analysed at a laboratory. UV254 can often vary with levels of colour and organic matter in the water and manufacturers of UV disinfection equipment will be able to advise on the suitability for particular waters.

    Maintenance of UV units

    UV irradiation equipment is compact and simple to operate. Maintenance requirements are often modest (when compared to the alternatives), although specific systematic maintenance is essential. Other advantages include short contact time and the absence of any known by-products of significance to health. The principal disadvantage is the absence of any residual effect, necessitating careful attention to hygiene in the storage and distribution system.

    The build-up of scale on the sleeves of the lamps will eventually reduce their transmittance and they must be cleaned or replaced regularly. Some units have UV intensity monitors and alarms which provide a continuous check on performance and these are strongly recommended. These devices may prevent the flow of water if the required intensity of UV radiation is not achieved, for example when the lamps are warming up or because of scale formation. UV intensity monitors may not be available on smaller units and it is therefore essential that the manufacturer’s instructions regarding lamp warmup, cleaning and replacement are followed to ensure optimal performance.

    Additional monitoring and control features are available, including UV intensity monitor, lamp run time, and automatic water shut off in the event of lamp or power failure. Such features are desirable, and should be considered where practicable as a way of providing some basic safeguards against consumption of disinfected water.

    In the event of power or lamp failure, if the flow of water is not automatically interrupted, the drinking water produced will not be disinfected.

    Similarly, validated systems are recognised as offering additional safeguards regarding confirmation of applied dose. It is recognised however that few validated systems are available in the sizes typically used in private supplies. In all cases approved products designed for drinking water treatment should be used.

    The intensity of UV radiation emitted decreases with lamp age. Typical lamp life is about 10 to 12 months, after which the output is about 70% of that of a new lamp. Manufacturers will advise on lamp maintenance requirements. It is worth noting that visually a lamp will still appear the same, even when output has decreased, and so the fact that a lamp is emitting light is not necessarily a guarantee that it is delivering the required dose. Lamp replacement is usually a simple operation but may involve some downtime of the system. This difficulty may be overcome by use of multiple units or by having a treated water storage tank capable of maintaining supply whilst maintenance is carried out.

    Record keeping

    It is recommended that copies of manufacturers’/suppliers’ operating and maintenance instructions be retained by the supply owner. In addition, a maintenance log should be maintained by the owner to record details of maintenance carried out and schedules for future maintenance.

    Find out more

    Pipe and fittings corrosion

    Corrosion is the partial dissolution of the materials constituting the treatment and supply systems, tanks, pipes, valves, and pumps. Pipe and fittings corrosion may lead to structural failure, leaks, loss of capacity, and deterioration of chemical and microbiological water quality. The internal corrosion of pipes and fittings can have a direct impact on the concentration of some water constituents, including lead, copper and nickel. Controlling pipe and fittings corrosion is therefore an important aspect of the management of a water supply system.

    Pipe and fitting corrosion: by material

    Concrete is a composite material consisting of a cement binder in which an inert aggregate is embedded. Cement is primarily a mixture of calcium silicates and aluminates together with some free lime. Cement mortar, in which the aggregate is fine sand, is used as a protective lining in iron and steel water pipes. In asbestos-cement pipe, the aggregate is asbestos fibres. It should be noted that research has indicated that the use of asbestos in cements in water mains does not pose a health risk. Cement is subject to deterioration on prolonged exposure to aggressive water. This can be, due either to: the dissolution of lime and other soluble compounds; or, to chemical attack by aggressive ions such as chloride or sulphate and this may result in structural failure. Aggressiveness to cement is related to the “Aggressivity Index”, which has been used specifically to assess the potential for the dissolution of concrete. A pH of 8.5 or higher may be necessary to control cement corrosion.



    Photo showing concrete riser pipes emerging from a borehole

    Copper tubing may be subject to general corrosion, impingement attack and pitting corrosion. General corrosion is most often associated with soft, acid waters; waters with pH below 6.5 and hardness of less than 60 mg/l CaCO3 are very aggressive to copper. The pitting of copper is commonly associated with hard groundwater having a carbon dioxide concentration above 5 mg/l and high dissolved oxygen. Surface waters with organic colour may also be associated with pitting corrosion. A high proportion of general and pitting corrosion problems are associated with new pipe in which a protective oxide layer has not yet formed.

    Photo showing spring source with copper spout.

    Lead corrosion (plumbosolvency) is of particular concern. Lead piping is still common in old houses, and lead solders have been used widely for jointing copper tube. The solubility of lead is governed by the formation of insoluble lead carbonates. The solubility of lead increases markedly as the pH is reduced below 8 because of the substantial decrease in the equilibrium carbonate concentration. Thus, plumbosolvency tends to be at a maximum in waters with a low pH and low alkalinity, and a useful interim control procedure pending pipe replacement is to maintain pH in the range 8.0 to 8.5 and possibly to dose orthophosphate.

    Photo showing water storage tank that could be lead.

    Concentrations of nickel up to around 1 mg/l may arise due to the leaching of nickel from new nickel-chromium plated taps and from stainless steel pipes and fittings. Nickel leaching reduces over time. Increase of pH to control corrosion of other materials should also help to reduce leaching of nickel.

    Photo of otside tap that has metal fittings.

    Physical removal of contaminants

    This is a guide to the treatment processes based on the physical removal of contaminants through filtration, settling (often aided by some form of chemical addition) or biological removal of microorganisms. Usually, treatment consists of a number of stages, with initial pre-treatment by settling or pre-filtration through coarse media, filtration followed by disinfection. This is called the multiple barrier principle.

    Filtration

    Turbidity and algae are removed from raw waters by screens, gravel filters, slow sand, rapid gravity filters or cartridge filters. Many small private supplies will rely on cartridge filters consisting of a woven or spun filter within a housing.

    Pressure filters

    Pressure filters are used where it is necessary to maintain hydraulic head in order to eliminate the need for additional pumping. The filter bed is enclosed in a cylindrical shell. Small pressure filters capable of treating up to approximately 15m³/h can be manufactured in glass reinforced plastics. Larger pressure filters are manufactured in specially coated steel. Operation and performance are generally as described for the rapid gravity filter (see below) and similar facilities are required for backwashing and disposal of the dilute sludge. A similar range of contaminants can be removed depending on the filter medium.

    Membranes

    Membrane processes used in water treatment are reverse osmosis, ultrafiltration, microfiltration and nanofiltration. Membrane processes can provide adequate removals of pathogenic bacteria, Cryptosporidium, Giardia, and potentially, human viruses and bacteriophages. However, they should not be relied upon as the sole means of disinfection as in the case of the types of systems encountered in private supplies there is no simple means to check membrane integrity to warn of potential breakthrough of microorganisms. Characteristics of membrane processes are illustrated in Figure 1.

    Diagram shows various materials found in water, their typical size and which type of membrane will likely remove them.
    Figure 1: Characteristics of membrane processes


    If two solutions are separated by a semipermeable membrane, i.e. a membrane that allows the passage of solvent but not of the solute, the solvent will pass from the lower concentration solution to the higher concentration solution. This process is known as osmosis. It is possible, however, to force the flow of solvent in the opposite direction, from the higher to the lower concentration, by increasing the pressure on the higher concentration solution. The required pressure differential is known as the osmotic pressure and the process as reverse osmosis.
    Reverse osmosis results in the production of a treated water stream and a relatively concentrated waste stream. Typical operating pressures are in the range 15 to 50 bar depending on the application. Membrane pore sizes are less than 0.002μm. The most common application of reverse osmosis is desalination of sea water although the use of reverse osmosis for nitrate removal has also been proposed. In the case of private water supplies, reverse osmosis units sold as point of use devices are probably the most common type of membrane process encountered.

    Ultrafiltration is similar in principle to reverse osmosis, but the membranes have much larger pore sizes (typically 0.002 to 0.03μm) and operate at lower pressures. Ultrafiltration membranes reject organic molecules of molecular weight above 800 and usually operate at pressures less than 5bar.

    Microfiltration is a direct extension of conventional filtration into the sub-micron range. It is capable of sieving out particles greater than 0.05μm and will remove most bacteria and amoeboid cysts. It has been used for water treatment in combination with coagulation or powdered activated carbon (PAC) to remove viruses, bacteria, dissolved organic carbon and to improve permeate flux. Microfiltration membranes have pore sizes typically in the range 0.01 to 12μm and do not separate molecules but reject colloidal and suspended material at operating pressures of 1 to 2bar.

    Nanofiltration uses a membrane with properties between those of reverse osmosis and ultrafiltration membranes; pore sizes are typically 0.001 to 0.01μm. Nanofiltration membranes allow monovalent ions such as sodium or potassium to pass but reject a high proportion of divalent ions such as calcium and magnesium and organic molecules of molecular weight greater than 200. Operating pressures are typically about 5bar. Nanofiltration may be effective for the removal of colour and organic compounds.

    Screens

    Screens are effective for the removal of particulate material and debris from raw water and are used on many surface water intakes. Coarse screens will remove weeds and debris while band screens or microstrainers will remove smaller particles including fish and may be effective in removing large algae. Microstrainers are used as a pre-treatment to reduce solids loading before coagulation or subsequent filtration. A microstrainer may consist of a rotating drum fitted with very fine mesh panels, or may be a fixed mesh that the water flows through. The mesh will ensure that suspended solids, including algae, are retained. The extent of solids removal will be determined by the mesh size and the nature of the raw water. Water will need subsequent treatment downstream and screens should only be considered as a preliminary treatment stage.

    Gravel filters

    Gravel filters may be used to remove turbidity and algae. A simple gravel filter for the protection of a stream or river inlet is described in Section 3.3.1. A larger gravel filter may consist of a rectangular channel or tank divided into several sections and filled with graded gravel (size range 4 to 30mm). The raw water enters through an inlet distribution chamber and flows horizontally through the tank, encountering first the coarse and then the finer gravel. The filtered water is collected in an outlet chamber. Solids removed from the raw water accumulate on the floor of the filter. Gravel filters can operate for several years before cleaning becomes necessary. The size of a gravel filter will depend on water quality, flow rate and size of gravel. A filter can be up to 12m long, 2 to 5m wide and 1 to 1.5m deep. The filter should normally be sized for a flow rate of between 0.5 to 1.0 cubic metres per square metre of filter surface area per hour (m3/m2.h). A gravel filter will need subsequent treatment downstream, and should only be considered as a preliminary treatment stage.

    Slow sand filters

    Slow sand filters, sometimes preceded by microstrainers or coarse filtration, are used to remove turbidity, algae and microorganisms. Slow sand filtration is a simple and reliable process and is therefore often suitable for the treatment of small supplies provided that sufficient land is available. Slow sand filters usually consist of tanks containing sharp sand (size range 0.15-0.30mm) to a depth of between 0.5 to 1.5m. For small supplies, modular units of 1.25m diameter are available – a tandem installation would occupy a concrete apron of about 8 to 10 m2. The raw water flows downwards and turbidity and microorganisms are removed by filtration in the top few centimetres of the sand. A biological layer of sludge, known as the schmutzdecke, develops on the surface of the filter that can be effective in removing microorganisms. Treated water is collected in underdrains or pipework at the bottom of the filter. The top few centimetres of sand containing the accumulated solids are removed and replaced periodically. Filter runs of between 2 and 10 weeks are possible, depending on raw water quality and flow rate. Slow sand filters are often operated in tandem; one in service whilst the other is cleaned and time allowed for the schmutzdecke to re-establish. A variant of the slow sand filter, the “Inverness filter”, has been widely used in Scotland. It uses the same grade of sand and operates at the same flow rate as the traditional slow sand filter but the water flows upwards. Filtration is achieved throughout the filter bed and a true schmutzdecke does not develop. The sand is “washed” by opening a valve at the bottom of the filter and allowing the filter bed to drain rapidly. Sand filters should be sized for a water flow rate of between 0.1 and 0.3 m3/m2.h. The flow rate should be controlled and the filter designed with a treated water reservoir of sufficient capacity to accommodate fluctuations in demand, and thus permit operation of filters at a steady and continuous rate.

    Rapid gravity filters

    Rapid gravity filters are most commonly used to remove floc from coagulated waters. They may also be used to remove turbidity, algae and iron and manganese from raw waters. Granular activated carbon media may be used to remove organic compounds. Rapid gravity sand filters usually consist of rectangular tanks containing silica sand and/or anthracite media (size range 0.5 to 1.0 mm) to a depth of between 0.6 and 1.0m. The water flows downwards and solids become concentrated in the upper layers of the bed. Treated water is collected via nozzles in the floor of the filter. The accumulated solids are removed periodically by backwashing with treated water, usually preceded by scouring of the media with air. Frequency of backwashing depends on loading rate and raw water quality and is typically every 24 hours. Backwashing can be initiated automatically after a predetermined headloss has been reached or may be carried out manually. Backwash flowrates will be stipulated by the manufacturer. It is important to achieve the required bed expansion in order to ensure filters are washing properly, but care must be taken to prevent loss of media with too high a flowrate. A dilute sludge that requires disposal is produced which may be discharged to sewer, soak away, or after treatment, to a watercourse provided that any required discharge consent is obtained.

    Coagulation and flocculation

    Coagulation and flocculation are used to remove colour, turbidity, algae and other microorganisms from surface waters. The addition of a chemical coagulant to the water causes the formation of a precipitate, or floc, which entraps these impurities. Iron and aluminium can also be removed under suitable conditions. The floc is separated from the treated water by sedimentation and/or filtration, although flotation processes may be used in place of sedimentation.

    The most commonly used coagulants are aluminium sulphate and ferric sulphate, although other coagulants are available. Coagulants are dosed in solution at a rate determined by raw water quality near the inlet of a mixing tank or flocculator. The coagulant is rapidly and thoroughly dispersed on dosing by adding it at a point of high turbulence. The water is allowed to flocculate and then passes into the sedimentation tank (sometimes known as a clarifier) to allow aggregation of the flocs, which settle out to form sludge. This sludge will need to be periodically removed.

    The advantages of coagulation are that it reduces the time required to settle out suspended solids and is very effective in removing fine particles that are otherwise very difficult to remove. Coagulation can also be effective in removing many microorganisms. The principal disadvantages of using coagulants for treatment of small supplies are the cost and the need for accurate dosing, thorough mixing and frequent monitoring. Coagulants need accurate dosing equipment to function efficiently and the dose required depends on raw water quality that can vary rapidly. The efficiency of the coagulation process depends on the raw water properties, the coagulant used and operational factors including mixing conditions, temperature, coagulant dose rate and pH value. The choice of coagulant and determination of optimum operating conditions for a specific raw water are normally determined by bench scale coagulation tests. Thus, while coagulation and flocculation are the most effective treatment for removal of colour and turbidity they may not be suitable for private supplies because of the level of control required and the need to dispose of significant volumes of sludge.

    Sedimentation

    Simple sedimentation (i.e. unassisted by coagulation) may be used to reduce turbidity and solids in suspension. Sedimentation tanks are designed to reduce the velocity of flow of water so as to permit suspended solids to settle under gravity. There are many different designs of tanks and selection is based on simple settlement tests or by experience of existing tanks treating similar waters. Without the aid of coagulation, these will only remove large or heavy particles, and due to the length of time this process will take, the system will usually require storage tanks to balance peaks and troughs in demand.

    Sedimentation tanks are usually rectangular with length to width ratios between 2:1 and 5:1. The depth of the tank is usually between 1.5 and 2.0m. The inlet and outlet must be at opposite ends of the tank. The inlet should be designed to distribute the incoming flow as evenly as possible across the tank width and to avoid streaming which would otherwise reduce sedimentation efficiency. Baffles may be installed to prevent short circuiting. The outlet should be designed to collect the clarified water over the entire tank width. The tank should be covered to prevent contamination and ingress. Sedimentation tanks require cleaning when performance deteriorates. This will not normally be more frequent than once per year.

    Aeration

    Air stripping is used for removal of volatile organics (e.g. solvents), carbon dioxide, disinfection by-products, some taste and odour causing compounds, and radon. It is a fairly specialist technique, and not commonly found as a treatment process on private water supplies, although aeration can sometimes be found in the oxidation stage of the treatment process for the removal of iron and manganese. Aeration processes are designed to achieve efficient mass transfer of oxygen into water and removal of gases and volatile compounds by air stripping. Oxygen transfer can usually be achieved using a simple cascade or diffusion of air into water, without the need for elaborate equipment. Stripping of gases or volatile compounds, however, may require specialised plant that provides a high degree of mass transfer.

    For oxygen transfer, cascade or step aerators are designed so that water flows in a thin film to achieve efficient mass transfer. Cascade aeration may introduce a significant headloss; design requirements are between 1.0 and 3.0m to provide a loading of 10 to 30m3/m2.h. If such headloss is unacceptable the alternative is to use compressed air diffused through a system of submerged perforated pipes. These types of aerator are used for oxidation and precipitation of iron and manganese. To achieve air stripping various techniques can be used including counter current cascade aeration in packed towers, diffused aeration in basins and spray aeration. Packed tower aerators are most commonly used because of their high energy efficiency and compact design.

    Water treatment for corrosion control

    To control corrosion in water distribution networks the methods most commonly applied are adjusting pH, increasing the alkalinity and/or hardness, or adding corrosion inhibitors such as sodium polyphosphates or silicates and orthophosphate. The quality and maximum dose to be used should be in line with appropriate national specifications for such water treatment chemicals. Although pH adjustment is an important approach its possible impact on other aspects of water supply technology, including disinfection, must always be taken into account.

    Treatment to reduce plumbosolvency usually involves pH adjustment. When the water is very soft (less than 50mg/l CaCO3), the optimum pH is about 8.0 to 8.5. Alternatively, dosing with orthophosphoric acid or sodium orthophosphate might be more effective particularly when plumbosolvency occurs in nonacidic waters. Wherever practicable, lead pipework should be replaced.

    Maintenance

    Maintenance should be proactive and involve a regular, preventative, maintenance programme, which enables early identification of problems. Equipment manufacturers’ maintenance instructions must be followed as a minimum requirement. Simple checks can be used to give forewarning of problems:

    • daily (or more frequent) checks on the operation of disinfection equipment
    • investigate the causes of dirty or discoloured water as it could be due to system failure
    • regular cleaning of filters in line with the manufacturer’s recommendations
    • routine site inspections to check for signs of pollution of the water source
    • structural inspections of the treatment plant, storage tanks and pipework

    Maintenance should always be performed by those deemed competent (trained and/or experienced and familiar with the equipment), ideally by the supplier’s servicing contractors. At the time a water treatment system is installed, the supplier should provide training on routine operation and maintenance tasks.

    A water supply system should include some form of treated water storage to provide a reserve of drinking water to cater for fluctuations in demand, timeout for planned maintenance or any problems. Storage may take the form of a small covered reservoir, providing sufficient head to supply more than one property, or may be a suitably positioned storage tank (e.g. in the roof space of the property), from which water flows under gravity to the taps.

    Design of water storage

    The tank or reservoir should hold a volume sufficient to accommodate the peak demand and the maximum period of interruption of supply, but must not be so large that water is allowed to remain static for lengthy periods because allowing the water to stagnate and develop aesthetic issues.

    All storage tanks must be insulated to guard against freezing during the winter and excessive warming during the summer months. The tank must be fitted with a robust lockable, and well fitting (but not airtight) lid to exclude light and pollutants. It is especially important to prevent the ingress of insects and animals and all openings must be protected using a fine mesh screen.

    Commissioning water storage

    The storage tank and other parts of the water supply system may be contaminated during construction and should therefore be disinfected before use. This is achieved by filling the system with a 20 mg/l solution of chlorine and leaving it to stand for several hours, preferably overnight. The chlorine solution should then be drained off and the system rinsed thoroughly using treated water.

    Maintenance of water storage

    The storage tank must be inspected regularly; at least annually and preferably every six months. If necessary, any accumulated silt can be flushed or siphoned out and the system disinfected as described above.

    Record Keeping

    Record keeping is an important part of looking after your private supply. Any treatment system should come with an appropriate set of instructions for use and operation. Your documents should also detail any maintenance requirements, including the criteria and regime for the replacement of any products or substances, which must meet the requirements of Regulation 5 (England and Wales).

    Reputable installers should provide a practical instruction and demonstration of the management and maintenance of the system to customers.

    The Inspectorate recommends that installers explain the importance of record keeping including the management and maintenance records of any newly installed system to assist with the risk assessment process, required under the regulations.

    The physical and chemical properties of water

    Water used as a source for any private supply of drinking water has its own particular physical and chemical properties. This may be derived from an environmental source, such as the soil or geology, or from contamination such as run-off from fields. It is essential that water is adequately understood and treated before it is used for domestic purposes (as defined in the Water industry Act 1991). This section gives an introduction as to how the physical and chemical properties of water are characterised and controlled.

    pH value

    The pH value of water is a measure of its acidity or alkalinity. Pure water is very slightly ionised into positively charged hydrogen ions (H+) and negatively charged hydroxide ions (OH–). Water is neutral when the numbers of hydrogen ions and hydroxide ions are equal. When the concentration of hydrogen ions exceeds that of hydroxide ions, the water is acidic and has a pH value less than 7. Conversely, when the concentration of hydroxide ions exceeds that of hydrogen ions, the water is alkaline and has a pH value greater than 7. The pH scale is logarithmic, therefore a change in pH value of one unit represents a tenfold change in the concentrations of hydrogen or hydroxide ions.

    Acidity in raw water can result from the dissolution of carbon dioxide to produce weak carbonic acid. Groundwater and surface water may also contain organic acids produced during the decomposition of vegetation. Surface water derived from a peaty moorland catchment may have a pH value as low as 4. Alkaline waters result almost entirely from the dissolution of the bicarbonate, carbonate and hydroxide salts of calcium, magnesium, sodium and potassium, for instance from limestone aquifers. Soft acidic waters can cause corrosion of pipework and the dissolution of metals such as copper, zinc and lead. Hard alkaline waters can cause scale formation and some hard waters may also be plumbosolvent.

    The UK drinking water quality regulations include pH as an indicator parameter and specify a minimum pH of 6.5 and a maximum pH of 9.5. In water treatment, the pH value can be changed by aeration and alkali or acid dosing.

    Hardness

    Water hardness is caused by dissolved salts of calcium and magnesium. Total hardness consists of temporary and permanent hardness. Temporary hardness is caused almost entirely by the carbonates and bicarbonates of calcium and magnesium. Temporary hardness is precipitated by evaporation and boiling. Permanent hardness is caused almost entirely by the sulphates and chlorides of calcium and magnesium. Permanent hardness is not precipitated by boiling.

    The hardness of waters, expressed in mg/l CaCO3 (calcium carbonate), can be classified as shown below:

    Water
    Hardness (mg/l CaCO3)
    Softup to 50
    Slightly hard100 – 150
    Moderately hard150 – 200
    Hard200 – 300
    Very hardMore than 300
    Table 1: Water Hardness guide


    The Drinking Water Directive and the UK drinking water quality regulations do not specify standards for hardness, calcium or magnesium. Softening can be achieved by lime-soda softening, where the addition of lime (Ca(OH)2) and sodium carbonate (Na2CO3) to the water causes the hardness compounds to precipitate. An alternative method, common in domestic water softeners, is ion-exchange (base exchange), whereby the calcium and magnesium ions in the water are replaced by sodium ions. Where water is softened by base exchange softening it is important to provide an unsoftened outlet for potable purposes. Installation of a softener just before the hot water tank or boiler is a more economical method for preventing precipitation of hardness salts (limescale) than softening the whole supply.

    Colour

    Water can be coloured by humic and fulvic materials leaching from peat or other decaying vegetation and by naturally occurring salts of iron or manganese. Surface water derived from peaty moorland catchments may be strongly coloured. The characteristic brown colour of such water is variable and often shows a strong seasonal effect, with concentrations being greatest in late autumn and winter. Water derived from lowland rivers can similarly show a seasonal increase in colour following autumn leaf fall.

    Water may appear coloured because of material in suspension and true colour can only be determined after filtration. Colour is expressed in mg/l on the platinum-cobalt (Pt-Co) scale, which is equivalent to measurements expressed in Hazen units (°H). The removal of colour from water is necessary not only for aesthetic reasons but also because chlorination of highly coloured waters can give rise to high concentrations of trihalomethanes. High colour also reduces the efficiency of disinfection by UV irradiation, chlorination and ozonation and will also cause fouling of reverse osmosis membranes.

    The Drinking Water Directive includes colour as an indicator parameter without a numeric standard but with the requirement “Acceptable to consumers and no abnormal change”. The UK water quality regulations specify a standard of 20 mg/l Pt-Co. Filtration techniques may be applied to small supplies but the efficiency of colour removal is usually relatively poor.

    Turbidity

    Turbidity is caused principally by inorganic matter in suspension including mineral sediments (e.g. from chalk) and oxides of iron or manganese but organic matter including algae can also cause significant turbidity. Most surface waters show particularly high turbidity following periods of heavy rainfall, whilst groundwater generally shows low to very low turbidity. However, variations following heavy rainfall, for example, may indicate rapid recharge bringing in contaminants from the surface.

    Turbidity measurement gives a quantitative indication of the clarity of water and analysis is carried out using a nephelometer. Nephelometers measure the intensity of light scattered in one particular direction, usually perpendicular to the incident light and are relatively unaffected by dissolved colour. Nephelometers are calibrated against turbidity standards prepared from a suspension of formazin. The standard unit of turbidity is the nephelometric turbidity unit or NTU.

    Turbidity is removed because high turbidity can impair the efficiency of disinfection and for aesthetic reasons. The UK water quality regulations specify a standard of 4 NTU at consumers’ taps with an indicator parameter value of 1NTU in water leaving a treatment works. A variety of filtration techniques can be successfully applied to small supplies, and cartridge filters are the most widely employed.

    Taste and odour

    Sources of taste and odour in source water include decaying vegetation, algae, moulds and actinomycetes. Taste and odour are usually associated with the presence of specific organic compounds released by the source agent which give rise to “earthy” or “musty” taste or odour. Chlorine and the by-products of chlorination can also cause complaints of taste or odour. Relatively high concentrations of iron, manganese and some other metals can impart an unpleasant metallic taste. Domestic plumbing materials and arrangements and in some circumstances water mains may also impart a noticeable taste or odour.

    The Drinking Water Directive includes taste and odour as indicator parameters without numeric standards but with the requirement “Acceptable to consumers and no abnormal change”. The intensity of odour and taste is expressed as a Dilution Number, which is the dilution of the sample with odour or taste free water at which the odour or taste is undetectable.

    Taste and odour are removed principally for aesthetic reasons. Taste and odour can be reduced or removed by aeration, ozonation or adsorption on activated carbon or, where chlorination is the source of taste or odour, by control of the disinfection process.


    Radioactivity

    All environmental water contains traces of naturally occurring radionuclides, the concentrations of which depend on the origin of the water. The natural radionuclides of most relevance to drinking water supplies are radon (Rn) and uranium (U). Radon is volatile and as a result it can be released from water as a gas. This is of concern if the release occurs within a confined space with insufficient ventilation. Radon and uranium are only found in significant concentrations in groundwater in certain parts of the UK, depending on the type of geology from which the groundwater originates. Further advice is available from local authorities, the British Geological Survey and the Radiation Protection Services of UK Health Security Agency. These substances are not significant for any surface water sources in the UK.

    The concentration of radioactive elements in water is expressed in terms of their activity, in Bequerels per litre (Bq/l). The UK water quality regulations specify a standard of 0.1 Bq/l as gross alpha activity and 1 as gross beta activity.

    Treatment for radon cannot include point-of-use systems fitted to the tap because, being volatile, it is released into the atmosphere whenever water is used. Under-sink treatment using an activated carbon filter is also inadvisable because the filter would become radioactive. Radon removal treatment therefore has to be installed before entry of water into a building and aeration is the preferred treatment technique although other methods are feasible. Uranium removal is best achieved by point-of-use systems.

    Distribution network

    The system of pipes and tanks that store and convey water following treatment to consumers’ taps is known as a distribution network. These systems may also include valves, hydrants, pumps, connection facilities and inspection points or other fittings for control and/or maintenance purposes. Even where effective treatment is used to secure a wholesome supply of drinking water, its quality at the point of consumption may not be wholesome if the integrity of the distribution system is compromised.

    Managing networks

    The arrangement of distribution systems can be extremely variable, both in terms of their complexity and physical construction, and can range from simple single length pipe runs to larger more complex systems that are difficult to trace. In either case, even small networks can span distances from a few meters to several miles. Consequently, the number of potential or actual hazards present in any distribution system can be numerous, diverse and variable. In turn the risks that these present can and will have a direct bearing on water quality if the system is not adequately constructed, managed and/or maintained according to its layout and design, irrespective of its age, which in some cases might be significant.

    Photo of pipes installed at a private supply. Pipes are lagged, within a building and raised from the ground.

    Risks to water quality can be mitigated and controlled by an awareness of the hazards and sensible and simple management and maintenance of the system. For example, routine cleaning of storage facilities, having suitably sized robust and covered storage tanks and reservoirs, periodic flushing of the system through taps and hydrants and the use of approved water fittings (plumbing parts and substances). The inclusion of backflow protection devices such as check valves are also an essential component of any distribution system to prevent contaminants being sucked or pushed into the system through pressure differentials.

    Photo of pipes and fittings at a private supply. Pipes are open, outside in grass, and disappear into the undergrowth.

    The identification of risk on any distribution system can be difficult owing to the pipes and tanks often being underground or hidden, which hampers inspection. Therefore the water quality impact of deficiencies in a distribution network may not become evident until it manifests, either through monitoring (sampling and analysis), or more usually through objectionable taste, odour or appearance at the point of consumption.

    Pipes at a private supply. Pipes have a number of complex fittings. Pipes disappear underground.

    Regulation 5

    Further detail and advice can be gained from local authorities and from guidance on regulation 5 in England and Wales which contain useful information on best practice for plumbing systems, especially regarding backflow protection and prevention of contamination of supplies.

    Find out more about product regulation.

    Source Protection

    The type of water source will determine the presence and concentrations of any contaminants. Private supply owners/users should take care to protect the source of water to ensure the treatment can remain appropriate.

    Guidance and checklists

    Outlining the roles and responsibilities for the protection of drinking water sources.
    An introduction to source types and best practice for construction
    An introduction in to how to understand and assess source pollution

    Disinfection

    Contamination by sewage or animal faeces is the greatest danger associated with water for drinking. This is because sewage from human or animal sources may contain the microorganism that cause disease. The use of disinfection to kill or inactivate microorganisms is necessary if the untreated water contains such organisms. Several disinfection methods are used in water treatment. Disinfection with ultraviolet (UV) irradiation and chlorine are the most widely used methods.

    Guidance and checklists

    Outlining the roles and responsibilities for the protection of drinking water sources.
    An introduction to source types and best practice for construction
    An introduction in to how to understand and assess source pollution

    How to ensure sufficient disinfection

    Different microorganisms have different susceptibilities to disinfectants, and disinfectants vary in their potency. For a given microorganism, disinfection efficiency is affected especially by disinfectant concentration and contact time, and also by the disinfectant demand of the water, pH and temperature. The product of disinfectant concentration (C in mg/l, measured at the end of the contact period) and time (t in minutes) is called Ct (in mg/l.min) and is an expression of exposure to the disinfectant:

    Ct = C × t

    The greater the Ct value, or exposure, the more effective disinfection is. Either concentration or contact time, or both, can be manipulated to obtain a desired Ct value. Values of Ct can be useful for comparing the efficiency of disinfectants; the lower the value of Ct to attain a given kill of microorganisms, the more effective the disinfectant. The Ct value can also be used to rank the relative susceptibility of different microorganisms; the higher the Ct value necessary to achieve a given level of kill the more resistant the microorganism.

    The World Health Organisation recommend that there should be a free chlorine concentration of ≥ 0.5 mg/L after at least 30 minutes contact time (so Ct = 30 x 0.5 = 15 mg.min/L), at pH < 8.0. And that at the point of delivery, the minimum free chlorine concentration should be 0.2 mg/L.

    In the case of ultraviolet irradiation Ct cannot be calculated in the same way and the exposure is expressed as UV radiation energy density, which is equivalent to (power × time) per unit area, expressed in milliwatt seconds per square centimetre (mW.s/cm2) or millijoules per square centimeter (mJ/cm2).

    Chlorine disinfection

    Chlorine is used in the treatment of water the world over. It removes harmful microorganisms and any remaining chlorine provides some safeguard against low-level contamination and growth within pipes and fittings.

    Types of chlorine

    Chlorination can be achieved by using liquefied chlorine gas, sodium hypochlorite solution or calcium hypochlorite granules. Chlorine gas is very reactive and highly toxic and must be carefully stored and handled.

    Gas chlorination is generally not appropriate for private supplies as leaks of chlorine gas are very dangerous. A separate area is necessary for storage of chlorine gas and an alarm system to detect leakage of chlorine must be installed. It is common practice to install alarm systems to indicate failure of the chlorine injector system or carrier water flow. Liquefied chlorine gas is supplied in pressurised containers. The gas is withdrawn from the cylinder and is dosed into water by a chlorinator, which both controls and measures the gas flow rate.

    Sodium hypochlorite solution (liquid) can be delivered to site in drums. No more than one month’s supply should be delivered at one time, as its decomposition (particularly on exposure to light) results in a loss of available chlorine and an increase in concentration of chlorate, relative to chlorine. Alternatively, sodium hypochlorite solution (0.5 to 1.0% mass per volume (m/V) available chlorine) can be generated on site by the electrolysis of brine (sodium chloride solution). A typical electro-chlorination system consists of a water softener, a salt saturator, a voltage rectifier, an electrolysis cell and a storage tank containing up to three day’s supply of hypochlorite solution. Hydrogen, which is produced during electrolysis, must be vented safely. These systems are compact and limit the need to store and handle the toxic and corrosive chlorination chemicals. There is a wide choice of equipment available for dosing sodium hypochlorite solution. Simple gravity fed systems in which sodium hypochlorite solution is dripped at a constant rate into a tank of water have been used successfully and have proven reliable provided that the rate of flow into supply and the chlorine demand of the water are constant. Where the flow is more variable, water powered hypochlorinators that adjust the flow of sodium hypochlorite proportionately to the flow of water may be suitable. Electric dosing pumps can operate under flow proportional or chlorine residual control and thus maintain a consistent chlorine residual under conditions of variable flow or chlorine demand.

    Calcium hypochlorite can be supplied in powdered, granular or tablet form (65 to 70% m/m available chlorine). Calcium hypochlorite is stable when dry and several month’s supply can be stored. It will however react with moisture in the air to form chlorine gas. Calcium hypochlorite dosing equipment is relatively simple. Most allow calcium hypochlorite to dissolve in a known volume of make-up water, which is then mixed with the main supply. Tablets are most commonly used, as their rate of dissolution is predictable. Control of dosage (proportional to the rate of dissolution) is often limited to changing the depth of immersion of the tablets in the make-up water or to changing the proportion of the make-up water to total flow.

    Chlorine chemistry

    Chlorine, whether in the form of pure chlorine gas, sodium hypochlorite or calcium hypochlorite, dissolves in water to form hypochlorous acid (HOCl) and hypochlorite ion (OCl–). For example, chlorine gas dissolves rapidly in water, initially forming hypochlorous and hydrochloric acids:

    Cl2 + H2O ⇔ HOCl + HCl

    Hypochlorous acid is a weak acid which undergoes partial dissociation to produce a hydrogen ion (H+) and a hypochlorite ion (OCl):

    HOCl ⇔ H+ + OCl

    The total concentration of chlorine, hypochlorous acid and hypochlorite ions is referred to as the free available chlorine. If ammonia is present in the raw water, the hypochlorous acid can react to produce chloramines. The total concentration of the chloramines and any organic nitrogen chlorine containing compounds is referred to as the combined available chlorine. Combined available chlorine is a less powerful disinfectant than free available chlorine but gives a more persistent residual.

    The formation of combined chlorine is due to a sequence of reactions whereby hydrogen in ammonia is progressively replaced by chlorine as follows:

    NH3 ⇒ NH2Cl ⇒ NHCl2 ⇒ NHCl3

    If a large chlorine dose is applied (relative to ammonia), as is practiced in breakpoint chlorination, then nitrogen is formed.

    2NH2Cl + Cl2 ⇒ N2 + 4HCl

    The effectiveness of chlorine for disinfection depends on the form of chlorine, its concentration and the contact time. Hypochlorous acid is a more powerful disinfectant than the hypochlorite ion and chlorination is usually practiced at values of pH favourable to its formation. The World Health Organization recommends that for the effective disinfection of drinking water “the pH should preferably be less than 8.0 and the contact time greater than 30 minutes, resulting in a free chlorine residual of 0.2 to 0.5mg/l”. Chlorination processes need to be carefully controlled in order to minimise the formation of taste and odour forming compounds. There may also be a need to control the formation of disinfection by-products including Trihalomethanes (THMs). Therefore, for private supplies, consideration should be given to using alternatives to chlorination, such as UV.


    Methods of chlorination

    Several regimes of chlorination can be used, including marginal (simple) chlorination, breakpoint chlorination, superchlorination/dechlorination and chloramination. On private supplies, it is probable that only marginal chlorination would be used in most cases. Marginal chlorination involves the dosing of chlorine to produce a suitable residual free available chlorine concentration. Breakpoint chlorination can and is used for removal of ammonia. Sufficient chlorine is added to exceed the demand for chloramine production and to ensure a free available chlorine residual. The chlorine dose must be carefully controlled to avoid forming dichloramine and nitrogen trichloride which can cause taste and odour problems. Breakpoint chlorination requires a dose of around 10 mg/l chlorine dosed per mg/l ammonia removed. The actual dose depends on water quality and has to be determined for each water.
    The design of the contact system is very important. Applied chlorine must be mixed rapidly with the water and then passed through a contact tank, ideally with baffles or a serpentine arrangement to prevent short circuiting or retention in dead zones.

    Control of chlorination

    Chlorine residual control is the most common method of control where chlorine is dosed continuously into the water. If the quality of the water and hence the chlorine demand varies appreciably, it is necessary to use a control system to maintain a constant chlorine residual. A sample of chlorinated water is withdrawn downstream of the chlorination system and the chlorine residual in the treated water is monitored continuously. The signal from the chlorine analyser system is used to adjust the chlorine dose thus maintaining the required residual chlorine concentration. Where water quality is consistent, constant rate control or flow proportional control may be appropriate. In the former, a constant dose of chlorine is applied and in the latter a chlorine dose proportional to the flow of water is applied automatically under control of a signal from the flow sensor. There is no standard for chlorine in the regulations, but excess levels give rise to complaints of taste and odour.

    Pipe and fittings corrosion

    Corrosion is the partial dissolution of the materials constituting the treatment and supply systems, tanks, pipes, valves, and pumps. Pipe and fittings corrosion may lead to structural failure, leaks, loss of capacity, and deterioration of chemical and microbiological water quality. The internal corrosion of pipes and fittings can have a direct impact on the concentration of some water constituents, including lead, copper and nickel. Controlling pipe and fittings corrosion is therefore an important aspect of the management of a water supply system.

    Pipe and fitting corrosion: by material

    Concrete is a composite material consisting of a cement binder in which an inert aggregate is embedded. Cement is primarily a mixture of calcium silicates and aluminates together with some free lime. Cement mortar, in which the aggregate is fine sand, is used as a protective lining in iron and steel water pipes. In asbestos-cement pipe, the aggregate is asbestos fibres. It should be noted that research has indicated that the use of asbestos in cements in water mains does not pose a health risk. Cement is subject to deterioration on prolonged exposure to aggressive water. This can be, due either to: the dissolution of lime and other soluble compounds; or, to chemical attack by aggressive ions such as chloride or sulphate and this may result in structural failure. Aggressiveness to cement is related to the “Aggressivity Index”, which has been used specifically to assess the potential for the dissolution of concrete. A pH of 8.5 or higher may be necessary to control cement corrosion.



    Photo showing concrete riser pipes emerging from a borehole

    Copper tubing may be subject to general corrosion, impingement attack and pitting corrosion. General corrosion is most often associated with soft, acid waters; waters with pH below 6.5 and hardness of less than 60 mg/l CaCO3 are very aggressive to copper. The pitting of copper is commonly associated with hard groundwater having a carbon dioxide concentration above 5 mg/l and high dissolved oxygen. Surface waters with organic colour may also be associated with pitting corrosion. A high proportion of general and pitting corrosion problems are associated with new pipe in which a protective oxide layer has not yet formed.

    Photo showing spring source with copper spout.

    Lead corrosion (plumbosolvency) is of particular concern. Lead piping is still common in old houses, and lead solders have been used widely for jointing copper tube. The solubility of lead is governed by the formation of insoluble lead carbonates. The solubility of lead increases markedly as the pH is reduced below 8 because of the substantial decrease in the equilibrium carbonate concentration. Thus, plumbosolvency tends to be at a maximum in waters with a low pH and low alkalinity, and a useful interim control procedure pending pipe replacement is to maintain pH in the range 8.0 to 8.5 and possibly to dose orthophosphate.

    Photo showing water storage tank that could be lead.

    Concentrations of nickel up to around 1 mg/l may arise due to the leaching of nickel from new nickel-chromium plated taps and from stainless steel pipes and fittings. Nickel leaching reduces over time. Increase of pH to control corrosion of other materials should also help to reduce leaching of nickel.

    Photo of otside tap that has metal fittings.

    Network Health checklist

    Use this network health checklist to understand and control the risks to your network:

    HazardHazard DescriptionRiskControl
    Long pipe lengthsPoor turnover: Water remains dormant for long periods, allowing it to stagnate.
    Elevated metals concentrations:
    Where pipes are metal, long exposure of water to the pipes may result in dissolution of metals into the water.
    Objectionable taste odour or appearance bacterial growth.
    Exceedance of metals standards (e.g. lead, copper, nickel).
    Regular flushing of twice the capacity of the pipe.
    Reduce pipe run when possible.
    Ensure the system is not unnecessarily convoluted or long.
    Age, condition and material of pipes.Potential for pipe material or component substances to dissolve (e.g. lead) or break off into the water (e.g. iron)Cloudy water, water with particles, and possible objectionable taste and odour. Potential health effects depending on materials.Replace or improve the pipes. Flushing in the short term may help, but it could make it potentially worse.
    Inappropriate location of pipes, vessels and chambersPipes and storage tanks/reservoirs located by waste facilities (latrines, toilets etc) or storage of contaminants such as oil could inadvertently leak into the supplyContaminants may enter the supply leading to illness and/or taste, odour and appearance issuesRelocate pipes/vessels to a less hazardous location. Ensure tanks, chambers and tanks are in robust condition with protective measures in place, such as bunding around oil storage and ensure pipes are lined or are run in a protective sleeve to prevent chemicals migrating through plastic.
    Age, condition and material of storage vessels (tanks, reservoir, chambers)Breakdown of materials into the water, potentially hazardous chemicals. Possible ingress pointsCloudy water, water with particles, objectionable taste and odour. Risk of decaying animals where they have gained access via holes, cracks etc.Upgrade or replace the vessel.
    Contamination via ingress pointsInappropriate covers on inspection chambers or storage reservoirs or tanks, including loft tanks, will
    allow ingress of animals, including vermin and insects or encourage algal or bacterial growth
    Ingress of land run off (pesticides, industrial pollutants), farm slurry or animal faeces from wildlife or grazing livestockInspection chambers, reservoir and tank roofs must have robust stock proof fencing. Ensure vents have a gauze covering, ensure chamber covers are adequately sealed and raised above the ground where possible.
    Low or irregular usage/little throughput of water.Low usage can encourage microbial growth or slime on the pipe walls called biofilmsTaste, odour and appearance problems.Ensure tanks and reservoirs are of a suitable size to ensure regular turnover, ensure the system is not unnecessarily convoluted or long
    “Dead spots” in the system (areas of low or no flow such as redundant pipework or dead spots due to poor mixing).As above. Water remains dormant for long periods, allowing it to stagnate, and this may get pulled back into the main flow of water.Taste, odour and appearance problemsRemove dead legs and dead spots where possible.
    Fittings on the system that are unapproved, in poor condition or inappropriate.Unapproved materials from fittings products or treatment chemicals can impart chemicals to the water or encourage microbial growth in the system.Taste, odour and appearance problems. Potential health issues depending on the circumstances and product.Products should be replaced with appropriate approved materials and products. See links to information on Regulation of product use (Regulation 5) here.
    Back flow risksContaminants get pushed or sucked into the system due to pressure changes due to absence of backflow prevention devices. Possible contamination of the public supply.Taste, odour and appearance problems. Potential health issues depending on the circumstances and contaminants.Ensure appropriate protection devices are installed. Consult local water company.
    Uncontrolled operator accessUncontrolled use of valve or hydrant operationInadvertent stirring up of sediment in the system leading to taste, odour or appearance issues.
    Connection of apparatus with inadequate backflow protection.
    Restrict access to use of valves and hydrants.
    Document a procedure for their operation by approved personnel.
    Table 1: Network health checklist.

    Private supply networks

    Introduction to distribution networks.
    An introduction to how pipes and fittings may corrode.
    How to control corrosion of pipes and fittings.
    Photo of pipes and fittings at a private supply. Pipes are open, outside in grass, and disappear into the undergrowth.
    Case studies with lessons in network contamination
    A guide to storage of water used for domestic purposes.
    A checklist of hints for common challenges

    The Network and Information Systems (NIS) Regulations 2018

    The NIS Regulations 2018 provides legal measures to protect essential services by improving the security of the network and information systems that support the continuation of these services. Drinking water supply and distribution has been designated an essential service within Schedule 1 of these Regulations. A water company supplying potable water to more than 200,000 people are classed as Operators of Essential Services (OES). OESs must take appropriate and proportionate measures to manage risks to their network and information systems and to prevent and/or minimise the impact of incidents to those systems.

    DWI have been transferred the function to undertake the operational Competent Authority (CA) duties to regulate OESs on behalf of Secretary of State (for England) and the Welsh Government (for Wales).

    The National Cyber Security Centre (NCSC) are the Single Point of Contact (SPOC) and Computer Security Incident Response Team (CSIRT) for incidents. Additionally they undertake the Technical Authority function supporting the OES and CA deliver the requirements of the Regulations.

    NIS incidents need to be reported to DWI without undue delay and no later than 72 hours of an OES being aware a NIS Incident has occurred. Our NIS Incident Reporting Guidance has been updated in October 2022 and has been emailed to company contacts. This will be made available on DWI’s NIS Resilience Direct area. Please email dwi.nis@defra.gov.uk if you require access to this guidance.

    The NIS team can be reached at dwi.nis@defra.gov.uk.