8 ESSEX AND SUFFOLK WATER PLC
Introduction
The Company supplies on average 477 Ml/d of water to a population of some 1.7 million people in Essex, south Norfolk and north Suffolk. The bulk of the Company’s water is surface derived from rivers in Suffolk and Essex. A bulk supply of raw surface water representing approximately 20% of the Company’s water is obtained from Thames Water Utilities. The remaining 5% of the water is derived from underground sources, principally chalk boreholes. The water from these sources is treated at 26 treatment works. Treated water is distributed through 110 water towers and service reservoirs and 8,370 km of mains. The supply area is divided into 66 water supply zones.
Overall water quality
At water treatment works and service reservoirs and in water supply zones, the Company carried out a total of 93,119 determinations in 2000. Of these, 99.86% demonstrated compliance with the relevant PCV, but 129 showed a contravention to have occurred.
Coliforms were not detected at 22 (85%) of the Company's 26 water treatment works. At 105 (95%) of the Company's 110 service reservoirs, coliforms were absent from at least 95% of samples. Of the Company's 66 water supply zones in 2000, all (100%) complied fully with the relevant water quality standards or had breaches of the standards which were either trivial or were fully covered by undertakings.
Microbiological quality of water leaving treatment works
The Company complied with the sampling frequencies required by regulation 17 at all its treatment works in 2000.
Table 8.1 shows the Company's performance in 2000, with data for 1999 and 1998 for comparison. Differences over the last three years in the number of treatment works, and samples from treatment works, in which coliforms were detected are not considered significant.
All contraventions of the standards at works are considered trivial or unlikely to recur.
Microbiological quality of water in service reservoirs
The Company complied with the sampling frequencies required by regulation 18 at all of its service reservoirs in 2000.
Table 8.2 shows the Company's performance in 2000 with data for 1999 and 1998 for comparison. There has been a significant increase since 1999 in the number of service reservoirs, and samples from service reservoirs, in which total coliforms were detected. All other differences at service reservoirs are not considered significant.
All contraventions of the standards at service reservoirs are considered trivial or unlikely to recur as remedial action has been carried out.
Water quality in water supply zones
The Company complied with the required sampling frequencies in all zones.
Table 8.3 shows the Company's performance in 2000, with data for 1999 and 1998 for comparison. There have been significant increases over the last three years in the number of zone failing to comply with the standard for nitrite. All other differences in zones are not considered significant.
All contraventions of the standards in zones are considered trivial.
Inspection
Computer systems and associated data management for drinking water quality information appearing on the Public Register
Consultants DERA, represented by Messrs. C Fisher and S Chapman, working under the direction of Mr W M Waite, Principal Inspector, carried out an audit in January 2000 of computer systems and associated data management for drinking water quality information appearing on the public register. Based on their report Mr Waite concluded that:
the systems examined appear to provide appropriate support to the business;
a number of key operational processes are not covered by appropriate up-to-date procedures; and
a number of technical issues were raised with reference IT security management.
Audit trail of five samples
Mr R M Walls, Consultant, working under the direction of Mr W M Waite, Principal Inspector, carried out an inspection of Essex and Suffolk Water Plc in October 2000. On the basis of his report Mr Waite concluded that:
water quality has been monitored by appropriate techniques. The Public Record has been maintained up to date.
Audit of plumbosolvency treatment and control programmes of work
In November 2000, Consultants WS Atkins, represented by Mr M Kimber, working under the direction of Mr P Halton, Inspector, carried out an audit of the Company as part of the Inspectorate’s work in agreeing with water companies’ their programmes of works to secure compliance with new lead standards. Based on Mr Kimber’s report Mr Halton, concluded that:
the Company’s process of sites/scheme selection for plumbosolvency treatment and/or optimisation measures is sound;
the integrity of the data submitted to the Inspectorate and used for assessing plumbosolvency was largely confirmed;
the schemes audited are justified on water quality reasons; and
the Company’s proposed steps to be taken and the proposed completion dates are generally sound.
Follow-up of response to recommendations, Cryptosporidium sampling procedures and service reservoirs
Dr K J White, Inspector, carried out an inspection of Essex and Suffolk Water Plc in November 2000. Dr White concluded that:
the Company has made a positive response to the recommendations made in the inspection report relating to the investigation of Computer systems and associated data management for drinking water quality information appearing on the public record;
Mashbury service reservoir is in a state of good repair and that the site as a whole is well maintained and not likely to give rise to any water quality issues in the future; and there are no major pieces of work outstanding that require urgent completion;
the compliance sampling taps were generally of satisfactory construction and appropriately located. However there was evidence of a slight leak around the gland of each tap;
the Company has an informal policy on turnover of water in service reservoirs, however regular (daily) information is received and interpreted in terms of the normal operational profile of the reservoir and any deviation from this are acted upon;
the Company maintains its service reservoir level probes in a satisfactory condition and ensures the integrity of data generated by them;
the Company has in place a suitable programme to ensure that all its service reservoirs will fully meet the requirements of the Code of Practice on Security at service reservoirs within the next five years;
all appropriate measures (except the fitting of LPC4 hatch covers) to meet the requirements of the Code of Practice on Security at service reservoirs have been carried out at Mashbury;
the Company has an effective training programme in place and that all its samplers are appropriately trained in the principles of good practice for microbiological and Cryptosporidium sampling;
the procedures (for cryptosporidium sampling) are generally satisfactory but there are a number of amendments that could be made to improve adherence to the Standard Operating Protocol;
that there is an effective management process of the Cryptosporidium sampling activities in place. Reporting of anomalies is appropriate; and
there is a suitable auditor training programme and an effective audit process in place with respect to Cryptosporidium sampling procedures.
Inspection of distribution system improvement programme progress
In October 2000, Consultants RPS, represented by Mr J Sim, working under the direction of Mr P Halton, Inspector, carried out an audit of the Company’s progress with the mains renovation set out in the distribution Undertaking submitted by the Company. Based on Mr Sim’s report, Mr Halton concluded that:
the objectives of the undertaking remained valid;
the steps to be taken were defined with adequate precision;
a practicable timetable had been set; and
the Company was likely to meet the target renovation length by the date for completion of the work.
As a result of these inspections, 12 recommendations were conveyed to the Company for formal response. Four suggestions on various matters were also made. The Company is taking action or has already taken action on a number of the recommendations.
Improvement programmes
Three undertakings in respect of improvement programmes accepted by the Secretary of State from the Company were due for full completion or the completion of major steps during 2000 and all of these were completed on schedule.
The ongoing distribution system improvement programmes due for completion in 2010, which have been implemented by the Company, have been progressing satisfactorily.
Relaxations
An authorised relaxation of the standard for the sulphate parameter in one zone supplied by one treatment works had been granted to the Company by the Secretary of State in December 1998, subject to a review in 1999. As a result of the review the relaxation was renewed subject to a further review in December 2003.
Incidents
Four of the events notified during 2000 by the Company to the Secretary of State under the terms of the Water Undertakers (Information) Direction 1998 were regarded by the Inspectorate as constituting incidents in which either drinking water quality demonstrably deteriorated.
Two incidents have been assessed. The first involved the microbiological contamination of water supplies to parts of Grays, Essex, following work carried out on mains in the area by the Company. The second, which affected parts of Barking, Essex, also involved wholesomeness concerns following low level bacteriological failures in the water supply after a main in the area burst.
Two incidents, also relating to the detection of low level microbiological contamination, remain under consideration. One relates to the area around Barsham in Suffolk, and the other to areas supplied by Warley service reservoir.
No other events regarded as constituting incidents came to the attention of the Inspectorate in 2000.
Enforcement action
No enforcement action needed to be considered for the Company as a result of the Inspectorate’s work during 2000.
table 8.1 Essex and Suffolk Water plc
MICROBIOLOGICAL QUALITY OF WATER LEAVING TREATMENT WORKS2000 1999 1998 Number of water treatment works 26 26 26 Works with no sampling shortfall 26 26 26 COLIFORMS Total number of determinations 4,192 4,264 4,186 - number containing coliforms 6 5 3 - % containing coliforms 0.1 0.1 0.1 Treatment works with coliforms detected 4 4 3 - % of all works 15 15 12 FAECAL COLIFORMS Total number of determinations 4,192 4,264 4,186 - number containing faecal coliforms 1 1 0 - % containing faecal coliforms <0.1 <0.1 0.1 Treatment works with faecal coliforms detected 1 1 0 - % of all works 4 4 0
table 8.2 Essex and Suffolk Water plc
MICROBIOLOGICAL QUALITY OF WATER IN SERVICE RESERVOIRS2000 1999 1998 Number of service reservoirs 110 111 113 Service reservoirs with no sampling shortfall 110 111 113 COLIFORMS Total number of determinations 5,402 5,540 5,778 - number containing coliforms 43 20 12 - % containing coliforms 0.8 0.4 0.2 Service reservoirs with coliforms detected 31 16 11 Service reservoirs with coliforms detected in more than 5% of samples 5 2 0 - % of all service reservoirs 5 2 0 FAECAL COLIFORMS Total number of determinations 5,402 5,540 5,778 - number containing faecal coliforms 3 5 0 - % containing faecal coliforms <0.1 0.1 0 Service reservoirs with faecal coliforms detected 3 5 0 - % of all service reservoirs 3 5 0
table 8.3 Essex and Suffolk Water plc
WATER QUALITY IN SUPPLY ZONESColumns 'CBU' show, for determinations, contraventions covered by undertakings and, for zones, the total number of zones covered by undertakings in 2000. Column 'E' shows the number of zones for which new enforcement action is under consideration as a result of contraventions of the PCV in 2000. Please refer to the Introduction to Part 2 for more detailed explanation of this table. PARAMETER DETERMINATIONS in 2000 ZONES (66 in 2000)* Total Contravening PCV Non-compliant No. % CBU CBU E Number in: 2000 2000 1999 1998 Coliforms 4,466 32 0.7 0 3 0 0 0 0 Faecal coliforms 4,466 2 <0.1 0 0 0 2 2 2 Colour 582 0 0.0 0 0 0 0 0 0 Turbidity 541 0 0.0 0 0 0 0 0 0 Odour 579 0 0.0 0 0 0 0 1 0 Taste 579 0 0.0 0 0 0 0 1 0 Hydrogen ion 582 0 0.0 0 0 0 0 0 0 Nitrate 2,131 0 0.0 0 0 0 0 0 0 Nitrite 2,081 33 1.6 0 0 0 26 23 9 Aluminium 541 0 0.0 0 0 0 0 0 0 Iron 1,716 3 0.2 2 39 0 3 9 10 Manganese 610 1 0.2 0 0 0 1 1 0 Lead 1,033 1 0.1 0 0 0 1 0 2 PAH 271 1 0.4 0 0 0 1 0 0 Trihalomethanes 423 2 0.5 1 3 0 0 3 1 Total pesticides 1,246 0 0.0 0 0 0 0 0 0 Other pesticides 42,620 0 0.0 0 0 0 0 0 0 Phosphorous 572 0 0.0 0 0 0 0 0 1 Sulphate 110 0 0.0 0 0 0 0 0 1 Total Hardness 275 1 0.4 0 0 0 1 0 0 All others 8,507 0 0.0 0 0 0 0 0 0 TOTAL 73,931 76 0.1 3 - - - - - *66 zones in 1999; 66 zones in 1998.
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Published 11 July 2001
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