Notice of Regulation: Prescot North and South Service Reservoir
THE WATER SUPPLY (WATER QUALITY) REGULATIONS 2016
NOTICE UNDER REGULATION 28(4)
United Utilities Water Ltd: Prescot North and South Service Reservoirs
Reference: UUT-2021-00002
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 | Asset Reference | Associated Water Supply Zones |
|---|---|---|
Prescot North Service Reservoir | R432 | Z120 Lightshaw |
- The Drinking Water Inspectorate (‘the Inspectorate’) has received multiple regulation 28(1) reports of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated between 15 April 2019 and 28 January 2021 which state that there is or has been a significant risk of supplying water from Prescot North and South Service Reservoirs (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:
Hazard/Hazardous Event/Parameter | Hazard ID | Description of Risks |
|---|---|---|
E. coli | R432 | Microbiological risks associated with risk of potential ingress. Risks of coliforms associated with Total Coliforms water age. |
Total Coliforms | R432 | Microbiological risks associated with risk of potential ingress. Risks of coliforms associated with Total Coliforms water age. |
Cryptosporidium | R432 | Microbiological risks associated with risk of potential ingress. Risks of coliforms associated with Total Coliforms water age. |
Taste | R432 | Risks associated with water age. |
- The Company are required to satisfy the following:
Requirements
(a) to maintain the following measures for the period specified in each case:
- Maintain enhanced water quality sampling at Prescot North and South Service Reservoirs (SR) using flow cytometry.
Date: Ongoing for the duration of this Notice - Continuous maintenance and review of target chlorine residual and set points at Prescot North and South SRs.
Date: Ongoing for the duration of this Notice - Enhanced monitoring for coliforms, colony counts, and chlorine residuals within the downstream distribution system. Where there is a risk of cryptosporidium from ingress, cryptosporidium monitoring should be carried out.
Date: Ongoing for the duration of this Notice - Maintenance and checks of the flora and fauna at Prescot North and South SRs.
Date: Ongoing for the duration of this Notice - Site security checks, operational equipment checks, and SR external inspection visits at Prescot North and South SRs.
Date: Ongoing for the duration of this Notice - Continuous review of turnover and chlorine residuals as part of the Drinking Water Safety Plan risk assessment for Prescot North and South SRs.
Date: Ongoing for the duration of this Notice - Manage SR levels based on demand and alarm set points to ensure turn-over is optimised.
Date: Ongoing for the duration of this Notice - Maintenance, calibration and verification of water level control system at Prescot North and South SRs.
Date: Ongoing for the duration of this Notice - Record and Monitor discolouration customer contacts at appropriate detail during each SR outage period within the ICC and as part of the weekly distribution operational maintenance strategy (DOMS) process.
Date: Ongoing for the duration of this Notice - Planned work risk assessments to be completed prior to start on site and presented to the Water Quality Risk Board (WQRB).
Date: Ongoing for the duration of this Notice - Development and trial of operational plans to control SR level during outage period with network contingency plans documented.
Date: Ongoing for the duration of this Notice - Additional turbidity monitoring on the outlet mains.
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:
- Complete internal inspection (including robust flood test) and clean of the Prescot North and South SRs. Complete any remedial work required following the internal inspection of Prescot North and South SRs, before returning the SRs to service.
Date: 31 March 2023
(c) to audit whether the measures have been effective by the following means:
- Define an audit strategy to monitor the effectiveness of the above measures specified in section (a) and (b).
Date: 30 June 2021 - 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 Prescot North or South SR, 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 by 31 January and against the following milestones:
Date: Annually by 31 January- Confirm completion of internal inspection (including robust flood test) and clean Prescot North and South SRs. Confirm completion of remedial work required following the internal inspection.
Date: 30 April 2023
- Confirm completion of internal inspection (including robust flood test) and clean Prescot North and South SRs. Confirm completion of remedial work required following the internal inspection.
- Submit the strategy for auditing the effectiveness of the measures, as specified in (c)1.
Date: 31 July 2021 - Submit any revisions of the audit strategy produced under measure (c)2.
Date: Ongoing for the duration of this Notice - Submit a report in the event that any completed measure of this Notice needs 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 April 2024
- 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
Laura Moss
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
16 April 2021
DWI ref: UUT-2021-00002
Version 1