United Utilities Water Limited – Huntington Water Treatment Works

Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

Reference: UUT-2019-00003

Version Number: 5

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:

• Huntington Water Treatment Works – T215
• (Y1503 – Halton DMZ, Y1507 – Liverpool DMZ, Y1516 – St Helens DMZ, Y1518 – Southport DMZ, Y1520 – Vale Royal DMZ, Y1521 – Warrington DMZ, Y1522 – Wigan DMZ, Y1523 – Wirral DMZ.)

Details of this Notice:

1. 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 24 December 2018, which states that there is or has been a significant risk of supplying water from Huntington Water Treatment Works (WTW) (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
2. 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 ID
Non asset standard isolation	E.coli	T215C002243324
Non asset standard isolation	Coliform bacteria	T215C001243324
Non asset standard isolation	Turbidity	T215A002A243324
Non asset standard isolation	Cryptosporidium	T215C111243324
Underperformance of second stage filters	Manganese	T215A023245582
Consumer Acceptability	Taste	T215A004244434
Consumer Acceptability	Odour	T215A003244434

Table 1: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.

3. 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:

1. Operation of all processes within defined normal operating ranges with appropriate triggers, responses, contingency procedures and to company standard operating procedures.
   Date: Ongoing for the duration of this Notice.
2. Critical control points in the treatment process are monitored, protected and actioned via telemetry alarms to the company’s Integrated Control Centre.
   Date: Ongoing for the duration of this Notice.
3. Works process operated to requirements of the company Site Specific Disinfection Policy.
   Date: Ongoing for the duration of this Notice.
4. Compliance and operational data from the monitoring of Huntington works and associated water supply zones (WSZs) is reviewed as part of drinking water safety plan process.
   Date: Ongoing for the duration of this Notice.
5. Monitor coliforms, E. coli, turbidity, pH, chlorine residuals, taste and odour as part of the operational and statutory sampling programme at the works final compliance sampling point.
   Date: Ongoing for the duration of this Notice.
6. Continue to respond to all sample results that exceed regulatory standards and implement measures that protect public health, within the requirements of the regulations.
   Date: Ongoing for the duration of this Notice.
7. Ensure all treatment process stages contained within the Site-Specific Disinfection Policy are not bypassed. Adequate risk assessment and company authorisation is required if bypass is demonstrably necessary.
   Date: Ongoing for the duration of this Notice.
8. Should the second stage filters be bypassed, the company will carry out enhanced monitoring for Cryptosporidium, microbiological parameters, turbidity and manganese on the raw water, pre-contact tank and the final treated water.
   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:

1. Confirm programme of work required to enable shut down of Huntington WTW with run to waste facilities.
   Date: Complete.
2. Establish the baseline water quality performance for the Huntington works treatment processes based on the design criteria for the works, maximum flows and loading rates for each process. Put procedures in place to ensure that the works is operated within the established performance criteria, with appropriate validation, alarms and shutdown responses.
   Date: Complete.
3. Carry out a review of the site-specific disinfection policy (SSDP) following the completion (b)2.
   Date: Complete.
4. Upgrade in line with current Company Engineering Standards the site SCADA system and where necessary update any associated telemetry outstations.
   Date: Complete.
5. Relocation of backwash turbidity monitors
   Date: Complete.
6. Modify the operating parameters of the existing pumps identified as a result of dynamic modelling to reduce risk of overflow.
   Date: Complete.
7. First stage filter (GAC) outlet valve replacement-replace existing valves with a fast-acting valve and associated UPS and control
   Date: Complete.
8. Install shutdown of flow at the point of disinfection and/or final water compliance point to minimise risk of inadequately treated water entering supply.
   Date: 31 August 2028.
9. Install run to waste facilities for inadequately treated water or water not meeting the required standards for quality.
   Date: 31 August 2028.
10. Review and revise individual shutdown and start up to waste quality assurance procedures and ensure all site personnel are competent and confident in all aspects of the revised procedure and subsequent works operation.
    Date: 31 August 2028.
11. Carry out a review of the mitigation and treatment for taste and odour risks, from the River Dee, at Huntington works.
    Date: 31 August 2025.
12. Develop an action plan, based on the outcomes of the review in (b)11, with suitable timescales for implementation of improvement measures to the treatment stage.
    Date: 31 October 2025.
13. Implement the action plan developed in (b)12.
    Date: 31 August 2028.
14. Develop an operational management strategy for the filters at Huntington works to ensure that they are operated and managed in line with industry good practice.
    Date: 31 July 2025.
15. Carry out a gap analysis of the implementation of company Standard Operating Procedure (SOP) WP/S/001/07/01 “Filtration – Rapid Gravity, GAC and Filters Performing Oxidation and Manganese Removal,” at Huntington works.
    Date: 31 July 2025.
16. Develop an action plan, based on the outcome of the gap analysis in (b)15, with a view to improving the implementation of WP/S/001/07/01 “Filtration – Rapid Gravity, GAC and Filters Performing Oxidation and Manganese Removal.”
    Date: 31 October 2025.
17. Implement the action plan formulated in measure (b)16.
    Date: 31 August 2028.
18. Carry out an investigation of the roof over the second stage filters, with a view to preventing ingress into buildings housing water treatment.
    Date: 31 May 2025.
19. Produce an action plan, based on the investigation carried out in measure (b)18.
    Date: 30 June 2025.
20. Implement the action plan, produced in measure (b)19.
    Date: 31 August 2028.
21. Carry out a review into the condition and operation of the contact tanks at Huntington works. The review shall include, as a minimum, the frequency of inspection and whether this is adequate, modelling to simulate the flows through the contact tanks with the baffle curtains in-situ and not in-situ, prevention of short-circuiting and a reduction in the time taken to remove the contact tanks from supply for inspection and remedial works.
    Date: 30 September 2025.
22. Where improvement actions have been identified in measure (b)21, produce a plan to implement improvement actions as applicable.
    Date: 31 December 2025.
23. Implement the plan produced in measure (b)22.
    Date: 31 August 2028.
24. Following the implementation of the plan in measure (b)23, review the Site-Specific Disinfection Policy and other documents as applicable, to consider the outcomes of the review.
    Date:31 August 2028.
25. Following the implementation of the plan in measure (b)23, implement training of staff on any new policies, procedures or processes.
    Date: 31 August 2028.

(c) To audit whether the measures have been effective by the following means:

1. Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
   Date: 31 August 2025.
2. 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 Huntington Water Treatment Works, or not to so supply unless the specified conditions below are satisfied:

1. 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:

1. Provide a progress report annually.
   Date: by 31 January each year.
2. Confirm programme of works defined in step (b)1.
   Date: Complete.
3. Confirm completion and provide a report detailing outcome of measure (b) 2 and provide revised SSDP in (b)3.
   Date: Complete.
4. Confirm completion of step (b) 4 and 6
   Date: Complete.
5. Provide an Interim report demonstrating efficacy of optimisation measures in step (b)6
   Date: Complete.
6. Confirm completion of step (b)7
   Date: Complete.
7. Confirm completion of installation and that all relevant site procedures have been updated and all relevant staff trained in the new operational arrangements as required by steps (b) 8, 9 and 10.
   Date: 30 September 2028.
8. Provide the outcomes of the review in measure (b)11.
   Date: 30 September 2025.
9. Provide the action plan, developed in measure (b)12.
   Date: 30 November 2025.
10. Provide evidence of the completion of the implementation of the action plan, as required in measure (b)13.
    Date: 30 September 2028.
11. Submit the operational management strategy, devised in measure (b)14.
    Date: 31 August 2025.
12. Provide the outcome of the gap analysis, as required in measure (b)15.
    Date: 31 August 2025.
13. Provide the action plan developed in measure (b)16.
    Date: 30 November 2025.
14. Provide evidence of the completion of the implementation of the action plan, as required in measure (b)17.
    Date: 30 September 2025.
15. Provide the outcome of the investigation carried out in measure (b)18.
    Date: 30 June 2025.
16. Provide the action plan developed in measure (b)19.
    Date: 31 July 2028.
17. Provide evidence of completion of the implementation of the action plan, as required in measure (b)20.
    Date: 30 September 2028.
18. Provide the outcomes of the review carried out at Huntington Contact Tanks, as required in measure (b)21.
    Date: 30 November 2025.
19. Provide a copy of the plan produced under measure (b)22.
    Date: 31 January 2026
20. Provide evidence of completion of the implementation of the action plan, as required by measure (b)23.
    Date: 30 September 2028.
21. Provide evidence that the Site-Specific Disinfection Policy and other documents as applicable, have been updated, as required in measure (b)24.
    Date: 30 September 2028.
22. Provide evidence that staff have been trained on any new policies, procedures or processes, as required in measure (b)25.
    Date: 30 September 2028.
23. Review the risk assessment for Huntington WTW as required by regulation 27(3) and subsequently submit a revised regulation 28 report accompanied by a signed board level declaration.
    Date: When required and by 2 months after completion of Step (b) 8, 9 and 10.
24. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 30 September 2025.
25. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision.
26. 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.
27. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 September 2029.

Further Details of this Notice:

4. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
5. 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.
6. 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
10 June 2025.
Reference: UUT-2019-00003 v5