THE WATER SUPPLY (WATER QUALITY) REGULATIONS 2016
NOTICE UNDER REGULATION 28(4)
United Utilities Water Ltd: Treated Water Storage Tanks
United Utilities Water Ltd owned treated Water Storage Tanks, including service reservoirs, break pressure tanks, pump suction tanks and any other structures used to store treated drinking water, downstream of Water Treatment Works compliance sample points in the United Utilities Supply Region.
Improvement Programme Database Reference number – UUT 3563
THE SECRETARY OF STATE FOR ENVIRONMENT, FOOD AND RURAL AFFAIRS:
- has received a report from United Utilities (the “Company”) dated 01 October 2015 (the “Report”) which states that there is or has been a significant risk of supplying water from Treated Water Storage Tanks that would constitute a potential danger to human health.
- Gives Notice that the Company is required, in order to mitigate the risk, in accordance with Regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended).
For risks associated with:
E. coli, coliforms, Cryptosporidium, taste and odour.
(a) to maintain the existing operational measures set out in the Report as specified below:
Date: with immediate effect and until the revocation of this notice
- Inspection and Cleaning programme for Treated water storage tanks using robust flood testing procedure
- Enhanced sampling at the storage tanks using flow cytometry
- Maintenance and review of target chlorine residual and set points at the storage tanks
- Monitor coliforms, colony counts and chlorine residuals as part of the routine sampling programme within the downstream distribution system. Where there is a risk of cryptosporidium from ingress, cryptosporidium monitoring should be carried out
- Management of flora and fauna at the storage tanks
- Site security, operational equipment checks and storage tank external inspection visits
- Review as part of the DWSP risk assessment the water turn-over for all treated water storage tanks
- Manage Treated water storage tanks levels based on demand and alarm set points to ensure turn-over is optimised
- Maintenance, calibration and verification of treated water tank level control systems
(b) to make operational such measures as are specified below, by the date specified below:
Short term measures
- Review, revise and/or make operational and maintain, the following additional short-term measures;
- Review and update DWSP risk assessments for all Treated water storage tanks that cannot be removed from supply
- Confirm high level interventions required for all Treated water storage tanks that cannot be taken out of supply
- Develop revised risk assessment process for Treated water storage tanks to accurately identify and capture potential risks to water quality from the environment
- Develop a procedure for the acceptance of all completed remedial work, including acceptance criteria and sign-off process
Medium term measures
- Make operational and maintain the following additional medium-term measures;
- Using a risk-based approach to target assets in order of risk to water quality, carry out revised Drinking Water Safety Plan risk assessment using new approach for all Treated water storage tanks in the North West region
- Update the Drinking Water Safety Plan risk assessment and submit to the Inspectorate
Long term measures
- Make operational and maintain the long-term measures identified below;
- Using a risk-based approach to target assets listed in appendix A in order of risk to water quality, complete Internal Inspection and clean of all treated water storage tank compartments that can be taken out of supply using the robust flood testing procedure to ensure maximum coverage. Complete remedial work required on any tank found to have ingress
Date: 30 June 2022
- Make operational and maintain the long-term measures identified below for assets that cannot currently be removed from supply;
- Using a risk-based approach to target assets listed in appendix A in order of risk to water quality, deliver a programme of work to facilitate isolation of treated water storage tanks that cannot currently be taken out of supply
Date: 31 March 2022
- Once enabling works have been completed to isolate treated water storage tanks, complete internal inspection and cleaning of all compartments, using the robust flood testing procedure to ensure maximum coverage of the tank roof and joints. Complete remedial work required on any tank found to have ingress
Date: 30 June 2022
(c) to audit whether the measures have been effective by such means as specified below
- Define a strategy for auditing the effectiveness of the above measures by 31 August 2016, with updates as necessary, to include;
- • Enhanced monitoring for E. coli, coliforms, colony counts
- • Where a risk of Cryptosporidium exists, monitoring should be carried out
- • Full investigation of all detections of E. coli, coliforms or Cryptosporidium, or of a step change in colony counts
- Implement the audit strategy outlined in (c)1.
Date: Until revocation of this notice
(d) not to supply water for regulation 4(1) purposes from the treated water storage tanks listed in Annex A, or not to supply unless the specified conditions below are satisfied:
(e) to provide the following information in such time and manner as specified below to enable monitoring of progress
- Provide a progress report annually by 31 January and against the following milestones:
- Confirmation of audit strategy.
- Confirmation (b)1 short term measures of the interventions to enable all storage tanks to be taken out of supply
- Confirmation of (b)2 medium term measures following completion of DWSP and water turn-over calculations for all treated water storage tanks, and identification of assets where interventions are required
- Confirmation of (b)3 long term measure to complete internal inspections and cleaning of all storage tanks listed in appendix A that can currently be taken out of supply using robust flooding method to ensure maximum coverage
Date: 31 July 2022
- Confirmation of (b)4 long term measure to deliver programmes of works to take all storage tanks out of supply
Date: 31 August 2021
- Confirmation of (b)4 long term measure to complete internal inspections and cleaning of all storage tanks where the removal from supply has been enabled, using robust flooding method to ensure maximum coverage
Date: 31 July 2022
- Review the risk assessment for all sites and systems where work is undertaken, as required by Regulation 27(4) and subsequently submit a revised Regulation 28 report
Date: (in accordance with Regulation 28(1)) from time to time); and within 1 month of completion of the risk assessment.
- Submit a satisfactory completion report
Date: 30 June 2023
Please be aware that breach by the Company of this Notice may result in an enforcement notice, breach of which may itself attract a penalty.
This Notice may be amended or revoked by notice from the Secretary of State at any time.
Signed by authority of the Secretary of State,
Deputy Chief Inspector
27 January 2022