Northumbrian Water Limited – Horsley Contact Tank
Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)
Reference: NES-2024-00003
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:
- Horsley Water Treatment Works (T0700330)
Details of this Notice:
- 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 21 October 2020, which states that there is or has been a significant risk of supplying water from Horsley Water Treatment Works 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:
|
Description of Risk |
Hazard/ Hazardous Event/ Parameter |
Hazard I D |
|---|---|---|
|
To address the risk of ingress contamination and microbial growth. |
Total Coliforms (Confirmed) |
NNE_TRE_T0700330_C001_CFH |
|
To address the risk of ingress contamination and microbial growth |
E. coli (Confirmed) |
NNE_ TRE_T0700330_C002_CFH |
|
To address the risk of ingress contamination and microbial growth |
Clostridium Perfringens (Confirmed) |
NNE_ TRE_T0700330_C004A_CFH |
|
To address the risk of ingress contamination and microbial growth |
Enterococci (Confirmed) |
NNE_ TRE_T0700330_C003_CFH |
|
To address the risk of ingress contamination and microbial growth |
Colony Counts at 22°C |
NNE_ TRE_T0700330_C007_CFH |
|
To address the risk of ingress contamination and microbial growth |
Residual Disinfectant – Total |
NNE_ TRE_T0700330_C010_CFH |
|
To address the risk of ingress contamination and microbial growth |
Residual Disinfectant – Free |
NNE_ TRE_T0700351_C009_CFH |
- 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:
- Operate the contact tank in accordance with current company policy, standards and procedures aligning recognised standards of good practice.
Date: Ongoing for the duration of this Notice - Enhanced microbiological monitoring where the contact tank has not been inspected in accordance with the company’s policy, including where new risks to water quality from the asset are identified.
Date: Ongoing for the duration of this Notice - Complete frequent contact tank maintenance check visits and escalate issues that present a water quality risk in accordance with company policy and procedures.
Date: Ongoing for the duration of this Notice - Complete Remotely Operated Vehicle (ROV) inspections of the final water tank to monitor the condition of the internal baffle curtains. Date: Every 6 months, ongoing for the duration of this Notice
- Proactive grounds maintenance on all service reservoir sites and at outflow discharge points.
Date: Ongoing for the duration of this Notice - Maintain records of remedial work completed on the contact tank.
Date: Ongoing for the duration of this Notice - Maintain contingency plans to protect human health in the event of a risk associated with drinking water quality, which should include liaison with local authorities and UKHSA.
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:
- Confirm whether the tank will be removed from service by March 2025 to repair the internal baffle curtains and compile a report recording the results of the repairs or the reasoning behind why the company will not remove the final water tank from service to remediate the works, including a contingency plan to manage the asset whilst it is in operation. The report is to also include an asset specific risk assessment detailing how the company will manage the current risk to the treatment works drinking water quality compliance. Date: 31 December 2024
- Define and develop a programme of works to construct a new contact tank at Horsley works.
Date: 31 October 2024
- Complete the construction, installation and commissioning of the programme of works as specified under measure (b)2.
Date: 31 May 2027 - Compile a report following completion of each of the six monthly Remotely Operated Vehicle (ROV) inspections of the final water tank to monitor the condition of the internal baffle curtains as specified under measure (a)4. Date: 31 December 2024 and ongoing every six months for the duration of this Notice.
(c) To audit whether the measures have been effective by the following means:
- Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
Date: 31 October 2024 - 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 Horsley treatment works, 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.
Date: by 31 January each year. - Submit the decision and report as specified in measure (b)1. Date: 31 January 2025
- Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
Date: 30 November 2024 - Submit any revisions of the audit strategy produced under measure (c)2.
Date: Within 1 month of a revision - 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 - Submit the developed programme of works to construct the new contact tank, as specified in measure (b)2.
- Date: 30 November 2024
- Submit a report confirming the completion of the construction, installation and commissioning of the programme of works as specified under measure (b)3. Date: 30 June 2027
- Submit a report following completion of each of the six monthly Remotely Operated Vehicle (ROV) inspections of the final water tank as specified under measure (b)4. Date: 31 January 2025 and ongoing every six months 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 June 2028
Further Details of this Notice:
- 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).
Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
27 September 2024
Reference: NES-2024-00003