United Utilities Water Limited – Air Valve Risk Management Improvement Notice

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

Reference: UUT-2025-00002

Version Number: 1

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:

• All raw water mains downstream of boreholes without any particulate removal, treatment works, strategic mains, service reservoirs and distribution mains in all water supply zones within the company’s operating area.

Details of this Notice:

1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a set of regulation 28(1) reports of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the company dated on various dates, which state that there is or has been a significant risk of supplying water from company assets with air valves (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 I D
Elevated bacteriological risk from failure or underperformance of upstream asset	E. coli Coliforms Clostridium perfringens Enterococci spp.	For example: Z295C002305980, which relates to Z295 Altrincham zone, which is in Y1509 Manchester Supply System.
Contaminated land risk leading to ingress into a main.	Contamination	For example: Z295H062290402, which relates to Z295 Altrincham zone, which is in Y1509 Manchester Supply System.

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. Continue existing programmes of air valve inspections and maintenance.
   Date: Ongoing for the duration of this Notice.
2. Continue to review the company’s regulation 28 reports for the risks associated with air valves, to include findings and conclusions from the inspection process.
   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. Carry out a review of existing procedures for air valve inspections, undertaking a robust gap analysis. Draw up procedures for any type of air valve in use, for each asset type, where one does not exist already. This shall include appropriate records in the company’s asset management systems.
   Date: 30 September 2025.
2. Undertake a review of the approach to capturing proactive maintenance information for air valves to ensure that they are reliably captured across all locations and asset types in the companys clean water system.
   Date: 30 September 2025.
3. Implement a revised approach, using the findings from (b)2, to capture maintenance records for air valves.
   Date: 31 December 2025.
4. Develop a strategy outlining the approach to future inspection and maintenance of air valves.
   Date: 30 September 2025.
5. Implement inspection procedures for all air valve types within the company’s asset base.
   Date: 30 June 2026.
6. Develop and implement training for air valve inspections. Disseminate the training to all appropriate employees.
   Date: 30 April 2026.
7. Develop and implement a tracking system for air valve inspections to ensure that inspections are carried out within the defined inspection frequency.
   Date: 30 June 2026.

(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 October 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 All raw water mains downstream of boreholes without any particulate removal, treatment works, strategic mains, service reservoirs and distribution mains in all water supply zones within the company’s operating area, 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. Provide a copy of the air valve procedures produced following the review and gap analysis as detailed in (b)1.
   Date: 31 October 2025.
3. Provide the outcome of the review, as required in measure (b)2.
   Date: 31 October 2025.
4. Provide the outcome of the implementation of the revised approach, as required in measure (b)3.
   Date: 31 January 2026.
5. Provide the strategy developed in measure (b)4.
   Date: 31 October 2025.
6. Provide evidence to demonstrate the implementation of inspection procedures for all air valves, as required in measure (b)5.
   Date: 31 July 2026.
7. Provide evidence to demonstrate the implementation of training, as required in measure (b)6.
   Date: 31 May 2026.
8. Provide evidence to demonstrate the implementation of a tracking system for air valve inspections, as required by measure (b)7.
   Date: 31 July 2026.
9. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
   Date: 30 November 2025.
10. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
11. 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
12. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 31 January 2027.

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
13 August 2025
Reference: UUT-2025-00002