United Utilities Water Limited – Prenton Lower Service Reservoir
Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)
Reference: UUT3480
Version Number: 6
Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): United Utilities Water Limited, with registered number 02366678 (hereinafter called ‘the Company’).
Assets Affected:
| Asset Name | Reference |
|---|---|
|
Prenton Lower Service Reservoir |
R438 |
|
Prenton Upper Service Reservoir |
R437 |
|
Wirral Supply System |
UUL1523 |
Details of this Notice:
- 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 June 2015, which states that there is or has been a significant risk of supplying water from Prenton Lower Service Reservoir (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
- 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 |
|---|---|---|
| Integrity of service reservoir structure | Coliforms | R438C001294263 |
| Integrity of service reservoir structure | E. coli | R438C002294263 |
- 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:
- Regulatory sampling programme at SR.
Date: Ongoing for the duration of this Notice - Enhanced sampling at the SR for bacteriological parameters and chlorine residuals.
Date: Ongoing for the duration of this Notice - Maintenance and review of target chlorine residual and setpoints at the SR.
Date: Ongoing for the duration of this Notice - Monitor coliforms, colony counts and chlorine residuals as part of the routine sampling programme within the downstream distribution system.
Date: Ongoing for the duration of this Notice - Management of flora and fauna at the SR.
Date: Ongoing for the duration of this Notice - Management of the drainage at the SR.
Date: Ongoing for the duration of this Notice - Weekly site security, operational equipment checks and SR external inspection visits.
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:
- In respect of bacteriological issues review frequency of enhanced sampling, site inspections and target chlorine and set points and take necessary measures to protect public health.
Date: Ongoing for the duration of this Notice - Initiate capital programme to identify a solution to enable the isolation Prenton Lower SR. The final solution should be permanent in nature to allow future isolation for routine inspection and maintenance of this asset.
Date: Complete - Completion of the concept phase and issue of tender documents.
Date: Complete - Confirmation of the preferred permanent solution to isolate the SR, design and procurement.
Date: Complete - Completion of all capital works to enable isolation of the service reservoir.
Date: Complete - Completed Isolation and abandonment of R437 Prenton Upper SR.
Date: Complete - Internal Inspection of the service reservoir, identification of repairs in the reservoir structure or roof, clean and complete any identified repairs to the service reservoir structure and return to service.
Date: 31 August 2024
(c) To audit whether the measures have been effective by the following means:
- Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
Date: Complete - 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 Prenton Lower Service Reservoir, or not to so supply unless the specified conditions below are satisfied:
- 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:
- Provide a progress report annually.
Date: by 31 January each year. - Confirmation of the solution to enable isolation of the SR.
Date: Complete - Notify the DWI of any bacteriological infringement
Date: Immediately - Confirm completion of the ability for isolation of Prenton Lower Service Reservoir and abandonment of Prenton Upper Service Reservoir.
Date: Complete - Confirmation of completion of the long term measures including inspection of the service reservoir and completion of all repairs to the service reservoir.
Date: 30 September 2024 - Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
Date: Complete - Submit any revisions of the audit strategy produced under measure (c)2.
Date: Within 1 month of a revision - 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 - Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
Date: 30 September 2025
Further Details of this Notice:
- Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
- 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.
- 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
19 April 2024
Reference: UUT3480 v6