Northumbrian Water Limited – Air Valve Risk Management Improvement Notice

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

Reference: NES-2025-00008

Version Number: 1

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Northumbrian Water Limited, with registered number 02366703 (hereinafter called ‘the company’).

Assets Affected:

All raw water impounding reservoirs, raw water mains, treatment works, strategic mains, service reservoirs and distribution mains in water supply zones within the company’s operating area.

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 on various dates, which states that there is or has been a significant risk of supplying water from all company 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 risk from failure or underperformance of asset.	E. coli Coliforms Clostridium perfringens Enterococci spp. Turbidity	Companywide, affecting all water supply works and systems.

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. Maintain the accuracy of air valve location information held in the company’s Geographical Information System (GIS).
   Date: Ongoing for the duration of this Notice.
2. Maintain the accuracy and completeness of air valve information held in the company’s asset management systems.
   Date: Ongoing for the duration of this Notice.
3. Continue to act upon and escalate actions required to remediate and reduce the risk from faulty air valves.
   Date: Ongoing for the duration of this Notice.
4. Continuously 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. Implement the findings from the review of the company’s three geographical operating areas to standardise procedures and operations.
   Date: 28 February 2027.
2. Define and implement a risk category system for air valves across the company’s asset base. Implement an appropriate inspection frequency for all air valves, which shall include appropriate records in the company’s asset management systems.
   Date: 30 June 2026.
3. 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.
4. Develop and implement the company’s digital application for recording air valve inspections to remove the need for paper-based inspection records.
   Date: 30 June 2026.
5. Develop and implement an inspection procedure for all air valves within the company’s asset base.
   Date: 31 December 2025.
6. Develop and implement a training package for air valve inspections. Disseminate the training package to all appropriate employees.
   Date: 31 December 2025.
7. Review the company Asset Group Standard for both strategic and distribution mains to ensure that the appropriate requirements for air valves are included in both standards.
   Date: 31 December 2025.

(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: 30 September 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 impounding reservoirs, raw water mains, treatment works, strategic mains, service reservoirs and distribution mains in 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 evidence to demonstrate the implementation of the review, as required in measure (b)1.
   Date: 31 March 2027.
3. Provide evidence of the implementation of a risk category system, as required in measure (b)2.
   Date: 31 July 2026.
4. Provide evidence of the implementation of a tracking system, as required in measure (b)3.
   Date: 31 July 2026.
5. Provide evidence of the implementation of a digital application, as required in measure (b)4.
   Date: 31 July 2026.
6. Provide evidence to demonstrate the implementation of an inspection procedure, as required in measure (b)5.
   Date: 31 January 2026.
7. Provide evidence to demonstrate the training package has been designed, implemented and disseminated, as required in measure (b)6.
   Date: 31 January 2026.
8. Provide evidence to demonstrate that the Asset Group Standard has been reviewed and appropriate requirements included, as required by measure (b)7.
   Date: 31 January 2026.
9. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
   Date: 31 October 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 March 2028.

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
23 June 2025
Reference: NES-2025-00008