Drinking Water 2003

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 9,893 tests on samples of water leaving its 22 water treatment works, from its 33 service reservoirs and from consumers’ taps in its 14 water supply zones. Of these, 99.72% (9,865) complied with the standards set down in the Regulations. However, 0.28% (28) 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 water treatment works, in which coliforms or faecal coliforms were detected, were not considered significant.

During 2003, the single failure of the total coliform standard at one works was considered trivial, and unlikely to recur.

There were no failures of the faecal coliform standard.

The Company has no sites that require regulatory monitoring for Cryptosporidium.

Water quality in service reservoirs

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 service reservoirs, and in the number of tests carried out on samples from service reservoirs, in which coliforms or faecal coliforms were detected, were not considered significant.

During 2003, total coliforms were detected at one service reservoir. However, there was no failure of the total coliform standard at that reservoir.

There were no failures of the faecal coliform standard at any service reservoirs.

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 = 14)*
		No	%		2003	2002	2001
Coliforms	866	6	0.69	0	0	0	0
Faecal coliforms	866	1	0.12	0	1	1	0
Colour	56	0	0.00	0	0	0	0
Turbidity	56	0	0.00	0	0	0	0
Odour	63	0	0.00	0	0	0	0
Taste	63	0	0.00	0	0	0	0
Hydrogen ion	56	0	0.00	0	0	0	0
Nitrate	168	16	9.52	15	3	3	3
Nitrite	56	0	0.00	0	0	0	0
Aluminium	56	0	0.00	0	0	0	0
Iron	80	0	0.00	0	0	0	0
Manganese	56	0	0.00	0	0	0	0
Lead	17	0	0.00	0	0	0	0
PAH	79	3	3.80	0	2	2	1
Trihalomethanes	26	0	0.00	0	0	0	0
Total pesticides	14	0	0.00	0	0	0	0
Other pesticides	392	0	0.00	0	0	0	0
Hydrocarbons	14	0	0.00	0	0	1	1
Phosphorus	175	0	0.00	0	0	1	1
Potassium	38	0~	0.00	0	0	0	0
All others	850	0	0.00	0	0	0	0
TOTAL	4,047	26	0.64
~ Exceeded PCV but relaxed standard *14 zones in 2002 and 2001

The fifth column indicates the number of failures in zones already covered by legally binding undertakings given by the Company. These undertakings are given by the Company and require remedial work to be carried out to ensure compliance with the individual standard.

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	86	1.0 µg/l	0
Bromate	86	10.0 µg/l	0
1,2 dichloroethane	86	3.0 µg/l	0
Nitrite (exwater treatment works)	86	0.1 mg/l	0
Clostridium perfringens	4	0/100ml	0
Enterococci	59	0/100ml	0

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		14	10.0 µg/l	0	5.0 µg/l	0
Arsenic		14	50.0 µg/l	0	10.0 µg/l	0
Boron		14	2.0 mg/l	0	1.0 mg/l	0
Copper		14	3.0 mg/l	0	2.0 mg/l	0
Lead		17	50.0 µg/l	0	25.0 µg/l	0
					10.0 µg/l*	0
Nickel		14	50.0 µg/l	0	20.0 µg/l	0
Nitrite (at consumers taps)		56	0.1 mg/l	0	0.5 mg/l	0
PAH		79	0.2 µg/l	0	0.1 µg/l	0
Tetrachloroethene Trichloroethene		26 26	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 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:

Follow up of recommendations made during the 2002 inspections or in connection with water quality incidents

Steps have been taken to implement all of the recommendations arising from the 2002 Audit and inspection process and from assessments of water quality incidents.

Audit of progress with water treatmenter treatment works improvement programmes

A desk top audit of two schemes associated with improvement programmes at water treatment works was carried out. The scheme for nitrate at Babraham treatment works is progressing satisfactorily. However, the scheme for solvents at Linton had been delayed by two months due to land issues which are beyond the control of the Company.

Audit trails of selected microbiological test results

A vertical audit was carried out on one test result selected at random for the period June 2002. The Company is being required to take action on deficiencies identified with the transportation of samples and the time between analysis and incubation.

Audit trails of selected nonmicrobiological test results

Vertical audits were carried out on four test results selected at random for the period January and June 2003. The Company is being required to take action on analytical deficiencies identified in respect of its contract laboratory on the reviewing and recalculation of AQC charts for one sample.

Inspection of two water treatment works and one service reservoir.

Inspections were carried out at Croydon pumping station, Bluntisham Tower and service reservoir and St Ives Tower. The operation and management of all the treatment works and service reservoirs were satisfactory. However, the Company is being required to take action on a number of minor deficiencies identified at Bluntisham Tower.

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. However, there are minor issues arising regarding the installation and control of plumbosolvency treatment at Babraham treatment works that require resolving by the Company.

Incidents

No incidents were notified by the Company during 2003.

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

Two undertakings associated with treatment works were due for completion during 2003. These were to install treatment at Babraham treatment works to remove nitrate and to investigate the presence of hydrocarbons in the Sawston water supply zone. The undertaking for hydrocarbons in Sawston zone was completed on schedule. The undertaking at Brabraham works has been converted to an Authorised Departure.

One Regulation 41 programme of work to meet the new and revised standards set down in the new Water Supply (Water Quality) Regulations 2000 was due for completion by 30 September 2003. This was to install treatment at Linton treatment works to remove solvents. The programme was completed two months behind schedule due to external factors beyond the control of the Company.

No other improvement programmes at water treatment works or service reservoirs was due for completion 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 sites specified in the programme by 25 December 2003.