Drinking Water 2003
18 Southern Water Limited
|
Overall water quality supplied by Southern Water Limited in 2003: |
|||||||||||||||||||||||||
|
|||||||||||||||||||||||||
|
|
||||||||||||||||||||||||
Water quality at treatment works, in service reservoirs and in water supply zones
To be wholesome, water must comply with the water quality standards for the parameters set out in the Water Supply (Water Quality) Regulations 1989. In 2003, the Company carried out a total of 76,090 tests on samples of water leaving its 94 water treatment works, from its 210 service reservoirs and from consumers’ taps in its 116 water supply zones. Of these, 99.86% (75,987) complied with the standards set down in the Regulations. However, 0.14% (103) tests did not meet the standards. A list of the parameters, the relevant standards and their significance can be found at the beginning of this section.
Water quality leaving treatment works
A comparison of the Company’s performance in 2003 with data for 2002 and 2001, is given below. Differences over the last three years in the number of treatment works, and in the number of tests carried out on samples from treatment works, in which total coliforms and faecal coliforms were detected, were not considered significant.
 |
During 2003, failures of the total coliform standard at five works were considered trivial, or unlikely to recur.
One failure of the faecal coliform standard occurred at one works. It was regarded as trivial or unlikely to recur.
In 2003, 4,417 regulatory samples for Cryptosporidium were taken at 11 sites. Very low numbers of oocysts were detected in 73 samples from ten sites. All results were well below the treatment standard and there were no reported outbreaks of cryptosporidiosis.
Water quality in service reservoirs
A comparison of the Company’s performance in 2003 with data for 2002 and 2001, is given below. There has been a significant decrease since 2002 in the number of service reservoirs in which total coliforms were detected, and a significant decrease in the number of tests carried out on samples from service reservoirs, in which coliforms and faecal coliforms were detected.
 |
During 2003, total coliforms were occasionally detected at a number of service reservoirs. However, there were no failures of the total coliform or faecal coliform standard at any service reservoir.
Water quality in water supply zones
The table below shows the data for the key parameters and any other parameters where there was a failure of the standard. All other parameters were fully compliant. A comparison is also given for parameters failing the standards in 2002 and 2001.
| Parameter | Total number of tests |
Tests not meeting standard |
Number of
failures
covered by
Undertakings |
Number of zones not
complying with the standards
(number of zones in
2003 = 116)* |
|||
|---|---|---|---|---|---|---|---|
|
No
|
%
|
2003
|
2002
|
2001
|
|||
|
Coliforms
|
6,367
|
30
|
0.47
|
0
|
0
|
0
|
0
|
Faecal coliforms
|
6,367
|
3
|
0.05
|
0
|
3
|
1
|
1
|
Colour
|
817
|
0
|
0.00
|
0
|
0
|
0
|
0
|
Turbidity
|
841
|
2
|
0.24
|
0
|
2
|
0
|
0
|
Odour
|
414
|
0
|
0.00
|
0
|
0
|
0
|
0
|
Taste
|
387
|
0
|
0.00
|
0
|
0
|
0
|
0
|
Hydrogen ion
|
814
|
0
|
0.00
|
0
|
0
|
0
|
0
|
Nitrate
|
989
|
3
|
0.30
|
0
|
2
|
0
|
2
|
Nitrite
|
814
|
0
|
0.00
|
0
|
0
|
0
|
0
|
Aluminium
|
814
|
0
|
0.00
|
0
|
0
|
0
|
0
|
Iron
|
848
|
3
|
0.35
|
0
|
3
|
0
|
5
|
Manganese
|
817
|
0
|
0.00
|
0
|
0
|
0
|
0
|
Lead
|
528
|
0
|
0.00
|
0
|
0
|
3
|
2
|
PAH
|
601
|
43
|
7.15
|
0
|
27
|
19
|
30
|
Trihalomethanes
|
549
|
4
|
0.73
|
4
|
3
|
3
|
0
|
Total pesticides
|
255
|
0
|
0.00
|
0
|
0
|
0
|
0
|
Other pesticides
|
4,397
|
0
|
0.00
|
0
|
0
|
0
|
0
|
Benzo34pyrene
|
601
|
1
|
0.17
|
0
|
1
|
0
|
1
|
All others
|
8,533
|
0
|
0.00
|
0
|
0
|
0
|
0
|
TOTAL
|
35,753
|
89
|
0.25
|
||||
| *116 zones in 2002 and in 2001 | |||||||
The new Regulations
In 2003, the Company carried out monitoring for the six new parametric values set down in the new Water Supply (Water Quality) Regulations 2000. These Regulations came into force on 25 December 2003. The results are shown in the table below.
| Parameter |
Total number
of tests
|
New standard
|
Tests not meeting
the new standard
|
|---|---|---|---|
| Benzene |
348
|
1.0µg/l |
0
|
| Bromate |
345
|
10.0µg/l |
0
|
| 1,2 dichloroethane |
343
|
3.0µg/l |
0
|
| Nitrite (exwater treatment works) |
1,484
|
0.1mg/l
|
0
|
| Clostridium perfringens |
56
|
0/100ml
|
0
|
| Enterococci |
391
|
0/100ml
|
2
|
Compliance data for 2003 have also been analysed against the revised standards and the results are shown in the following table.
| Parameter | Total number of tests |
Current standard |
Number of tests not meeting current standard |
Revised standard |
Number of tests not meeting revised standard |
|
|---|---|---|---|---|---|---|
| Antimony |
116
|
10.0µg/l |
0
|
5.0µg/l |
0
|
|
Arsenic
|
116
|
50.0µg/l |
0
|
10.0µg/l |
0
|
|
Boron
|
116
|
2.0mg/l
|
0
|
1.0mg/l
|
0
|
|
Copper
|
466
|
3.0mg/l
|
0
|
2.0mg/l
|
2
|
|
Lead
|
520
|
50.0µg/l |
0
|
25.0µg/l |
1
|
|
|
10.0µg/l* |
7
|
|||||
Nickel
|
116
|
50.0µg/l |
0
|
20.0µg/l |
0
|
|
Nitrite (at consumers’ taps) |
116
|
0.1mg/l
|
0
|
0.5mg/l
|
0
|
|
PAH
|
603
|
0.2µg/l |
43
|
0.1µg/l |
0
|
|
Tetrachloroethene Trichloroethene
|
522 521 |
10.0 µg/l 30.0 µg/l |
0 0 |
} 10.0 µg/l |
0
|
|
| * Final standard not applicable until 2013 | ||||||
During 2003, the Company had in place a number of programmes of work to meet the new and revised standards.
Details of the new and revised standards can be found in chapter J ‘New Regulations and Associated Programmes of Work’.
Audit and inspection
The Company was inspected or audited by the Inspectorate or its appointed consultants on a number of occasions during 2003. Where relevant, report summaries are available in the ‘Business and Technical’ section of the Inspectorate’s website under ‘Audit and Inspection’. Details of the subject areas audited or inspected are given in the following paragraphs:
Audit of regulatory Cryptosporidium monitoring sites
The monitoring equipment at all regulatory sites visited during the year was found to be satisfactory.
Inspection of laboratory analysing for Cryptosporidium
The announced audit on the Company’s Cryptosporidium laboratory identified three regulatory breaches as well as a number of other minor deficiencies associated with the Standard Operating Protocol. The Company has taken the required remedial action to rectify the deficiencies identified.
Audit of progress with water treatment works improvement programmes
A desktop audit of four schemes associated with improvement programmes at water treatment works was carried out together with one site visit. The schemes were for nitrate and Mile Oak and Goldstone treatment works, for Cryptosporidium at Otterbourne and for THMs at Brede treatment works. General progress was satisfactory, and the Company has taken action to rectify the deficiencies identified.
Review of distribution system undertaking
Work for the programme of mains renovation set out in the Company’s distribution system undertaking, which is now complete, was found to be satisfactory.
Audit of response to selected consumer complaints
A desktop audit of the Company’s response to 12 consumer complaints about drinking water quality was carried out. The Company is being required to take action in respect of deficiencies associated with the time it took to respond to some customers.
Audit trails of selected microbiological test results
Vertical audits were carried out on two test results selected at random for the period February 2003 to March 2003. The Company is being required to take action on deficiencies identified with media performance and calibration.
Audit trails of selected nonmicrobiological test results
Vertical audits were carried out on eight test results selected at random for the period November 2002 to March 2003. The Company is being required to take action on deficiencies identified with sample scheduling in relation to one parameter; sample transport conditions in relation to five samples; and the method of analysis in relation to three parameters.
Audit of analytical requirements for nitrate and nitrite
Vertical audits were carried out of nitrate/nitrite samples taken in a single water supply zone over a sixmonth period to assess any changes in analytical requirements over time. The Company is being required to take action on deficiencies identified with sample scheduling; the method of analysis, and the calibration and analytical conditions; and its public record entries.
Inspection of one water treatment works and two service reservoirs
Inspections were carried out at Andover water treatment works and Downend and Brading service reservoir sites. The operation and management of the treatment works and service reservoirs were satisfactory. However, the Company is being required to take action on a number of minor deficiencies associated with site maintenance identified at Andover water treatment works and Downend service reservoir.
Audit of sampling arrangements
An audit was carried out on general sampling arrangements and on one sample round. A number of deficiencies were identified with sampling points, calibration and training records.
Audit of plumbosolvency treatment and control programmes
Progress with the programme of work for plumbosolvency treatment and control measures for lead was found to be satisfactory.
Incidents
The Inspectorate regarded four events notified during 2003 as incidents. Further details of these incidents are given in the table below.
All four of the incidents were fully investigated and assessed by the Inspectorate during 2003. Each was of relatively short duration and, where applicable, the Company took appropriate action to protect public health.
During 2003, investigations were also completed for three incidents that occurred in 2002.
| Nature of incident | Assessment completed during 2003 |
|---|---|
| Discolouration of water supplies | |
| Discolouration of supplies serving 400 properties in the Winchelsea area following a burst main. Loss of supplies | Yes |
| Loss of supplies resulting in 287 calls from properties served by Michelmersch reservoir and potentially affecting a population of 25,000. This was as a result of a shutdown at Timsbury WTW following UV system failure and subsequent failure to restart pumping. Loss of disinfection | Yes |
| Failure to chlorinate supplies feeding 63 properties in the Brede area in July 2003 due to equipment malfunction. Ground contamination | Yes |
| Contamination of ground near WTW boreholes as a result of fracture of the underground transfer pipeline between the storage tank and the site generator in January 2003 at Andover WTW serving a potential population of 58,113. | Yes |
Enforcement action
No enforcement action was considered for the Company as a result of the Inspectorate’s activities during 2003.
Improvement programmes
Water treatment works/service reservoirs
One undertaking associated with treatment works was due for completion during 2003. This was to install treatment at Brede treatment works for THM. The undertaking was not completed on schedule due to a delay with the completion of the design stage of the scheme. Installation of treatment is now due to be completed by October 2004. However, interim measures have been installed to achieve compliance with the THM standard.
Two Regulation 41 programmes of work to meet the new and revised standards set down in the new Water Supply (Water Quality) Regulations 2000 were due for completion in 2003. An integrated approach was adopted for these schemes, which was to install treatment to remove nitrate at Goldstone treatment works and subsequent blending at Mile Oak treatment works. The programme at Goldstone was completed on schedule. However, delays in completion at Mile Oak works was due to planning issues which were not within the control of the Company.
One statement of intent to reduce the risk of Cryptosporidium breaching the treatment standard at Otterbourne treatment works was due for completion during 2003. The programme was not completed on schedule as the Company needed to extend the period for monitoring. The Inspectorate has considered the reason for the delay to the programme as reasonable.
No other improvement programmes associated with water treatment works and service reservoirs were due for completion during 2003.
Distribution
Work for the Company’s distribution system undertaking is now complete. No mains were renovated during 2003.
Lead
The Company’s Regulation 41 programme of work to meet the revised standard for lead set down in the new Water Supply (Water Quality) Regulations 2000 has been progressing satisfactorily. Plumbosolvency treatment measures were installed at all but one site specified in the programme by 25 December 2003. Installation of treatment at the remaining works in the programme should be completed by June 2004.
