22 TENDRING HUNDRED WATER SERVICES LIMITED
Introduction
Tendring Hundred Water Services Limited supplies on average about 30 Ml/d of water to about 145,000 consumers in the Tendring peninsula of Essex. The demand can rise to about 48 Ml/d in summer. About 80% of the Company’s water supplies come from boreholes and are treated at Horsley Cross. The remainder comes from the River Colne and is stored in Ardleigh Reservoir before being treated at Ardleigh water treatment works. The Company has three treatment works on two sites, and distributes water through 930 km of pipes and eight service reservoirs to four 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 4,711 determinations in 2000. Of these, 99.89% demonstrated compliance with the relevant PCV, but five showed a contravention to have occurred.
Coliforms were not detected at any of the Company's three water treatment works or any of the Company's eight service reservoirs during 2000. Of the Company's four water supply zones in 2000, all 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 of its treatment works in 2000.
Table 22.1 shows the Company's performance in 2000, with data for 1999 and 1998 for comparison.
There were no contraventions of the microbiological quality standards at any of Company’s water treatment works in 2000.
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 22.2 shows the Company's performance in 2000, with data for 1999 and 1998 for comparison.
There were no contraventions of the microbiological standards at any of the Company's service reservoirs in 2000.
Water quality in water supply zones
The Company complied with the required sampling frequencies for all parameters in all zones.
Table 22.3 shows the Company's performance in 2000, with data for 1999 and 1998 for comparison. Differences over the last three years are not considered statistically significant.
All contraventions of the standards in zones are considered trivial.
Inspection
Audit of plumbosolvency treatment and control programmes of work
In November 2000, Consultants WS Atkins, represented by Mr S Ntifo, 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 Ntifo’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 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.
Audit trails of five samples
Mr R M Walls, Consultant, working under the direction of Mr W M Waite, Principal Inspector carried out audit trails on five samples chosen at random. Based on Mr Walls report Mr Waite concluded that:
The sampling and analytical arrangements are generally satisfactory. Some improvements could be made to the operation of control charts and other laboratory procedures. The analytical results have appeared on the Public Record in good time.
Follow-up of response to recommendations
The Inspectorate audited Tendring Hundred Water Services Ltd on two occasions in November and December 2000. The Inspectorate concluded that:
The sampling and analytical arrangements are generally satisfactory. Some improvements could be made to the operation of control charts and other laboratory procedures;
The analytical results have appeared on the Public Record in good time; and
The Company has taken satisfactory action on each of the recommendations made in 1999.
Contraventions of regulation 21(2)(d)(iii) were found in respect of two parameters. However, remedial action was to be taken speedily, so enforcement action was not necessary.
Review of procedures for operation and maintenance of the distribution network
In December 2000, Consultants Binnie, Black and Veatch working under the direction of Mr W M Waite, Principal Inspector carried a follow up investigation of the recommendations made during the 1999 audit of the Review of Procedures for Operation and Maintenance of the Distribution Network. Based on their report Mr Waite concluded that:
that to provide adequate responses to those recommendations where the response has been considered inadequate, the company extend its procedures to provide the following:
- Specific guidance on the rate of valve operation for valves of different diameters and with different differential pressures (Recommendations R1.3 - Implementation and monitoring, R2.3 - Recharging after Completion of the Maintenance or Repair and R9.1 - Guidance). The company considers that their staff are sufficiently well trained to operate valves in a correct manner but undertook to consider extending the procedure to include guidance on the maximum rate of operating valves.
- A procedure on the routine monitoring of the status of valves and on the condition of their markers (Recommendation R8.3 - Monitoring of Valve Status). The company stated that they do not have any plans to introduce routine monitoring of the status of valves at the present time.
Inspection of distribution system improvement programme progress
In September 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, three recommendations were conveyed to the Company for formal response. The Company is taking action or has already taken action on all of the recommendations.
Improvement programmes
No 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.
The distribution system improvement programme, due for completion in 2004, is on-going. The Inspectorate is in discussions with the Company concerning the volume of work required.
Incidents
No events regarded as constituting incidents in which drinking water quality demonstrably deteriorated 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 in, or pertaining to, the calendar year 2000.
table 22.1 Tendring Hundred Water Services Limited
MICROBIOLOGICAL QUALITY OF WATER LEAVING TREATMENT WORKS2000 1999 1998 Number of water treatment works 3 3 4 Works with no sampling shortfall 3 3 3 COLIFORMS Total number of determinations 631 622 674 - number containing coliforms 0 0 0 - % containing coliforms 0.0 0.0 0.0 Treatment works with coliforms detected 0 0 0 - % of all works 0 0 0 FAECAL COLIFORMS Total number of determinations 631 622 674 - number containing faecal coliforms 0 0 0 - % containing faecal coliforms 0.0 0.0 0.0 Treatment works with faecal coliforms detected 0 0 0 - % of all works 0 0 0
table 22.2 Tendring Hundred Water Services LImited
MICROBIOLOGICAL QUALITY OF WATER IN SERVICE RESERVOIRS2000 1999 1998 Number of service reservoirs 8 8 9 Service reservoirs with no sampling shortfall 8 8 9 COLIFORMS Total number of determinations 449 444 475 - number containing coliforms 0 0 0 - % containing coliforms 0.0 0.0 0.0 Service reservoirs with coliforms detected 0 0 0 Service reservoirs with coliforms detected in more than 5% of samples 0 0 0 - % of all service reservoirs 0 0 0 FAECAL COLIFORMS Total number of determinations 449 444 475 - number containing faecal coliforms 0 0 0 - % containing faecal coliforms 0.0 0.0 0.0 Service reservoirs with faecal coliforms detected 0 0 0 - % of all service reservoirs 0 0 0
table 22.3 Tendring Hundred Water Services Limited
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 (4 in 2000)* Total Contravening PCV Non-compliant No. % CBU CBU E Number in: 2000 2000 1999 1998 Coliforms 396 1 0.3 0 0 0 0 0 0 Faecal coliforms 396 1 0.3 0 0 0 1 1 0 Colour 44 0 0.0 0 0 0 0 0 0 Turbidity 52 1 1.9 0 0 0 1 0 0 Odour 44 0 0.0 0 0 0 0 0 0 Taste 44 0 0.0 0 0 0 0 0 0 Hydrogen ion 45 0 0.0 0 0 0 0 0 0 Nitrate 44 0 0.0 0 0 0 0 0 0 Nitrite 52 1 1.9 0 0 0 1 0 0 Aluminium 44 0 0.0 0 0 0 0 0 0 Iron 164 0 0.0 0 0 0 0 0 0 Manganese 52 1 1.9 0 0 0 1 0 0 Lead 24 0 0.0 0 0 0 0 0 0 PAH 20 0 0.0 0 0 0 0 0 0 Trihalomethanes 39 0 0.0 0 0 0 0 0 0 Total pesticides 43 0 0.0 0 0 0 0 0 0 Other pesticides 374 0 0.0 0 0 0 0 0 0 All others 674 0 0.0 0 0 0 0 0 0 TOTAL 2,551 5 0.2 0 - - - - - *4 zones in 1999; 4 zones in 1998
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Published 11 July 2001
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