Notice of Regulation: Gayton Water Treatment Works

THE WATER SUPPLY (WATER QUALITY) REGULATIONS 2016 (AS AMENDED)

NOTICE UNDER REGULATION 28(4)

ANGLIAN WATER: AMP7 Gayton WTW Nitrate removal scheme

Gayton WTW
West Norfolk – Marham/Bexwell Supply System, SSC-001-WNM

Legal Instrument Database Reference number: LI/ANH/2018/00004

THE SECRETARY OF STATE:

1. has received a report from Anglian Water (the “company”) dated 20 November 2017 (the “Report”) which states that there is or has been a significant risk of supplying water in buildings, that could constitute a potential danger to human health.
2. GIVES NOTICE to the company under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended) that it must satisfy the following requirements:

For risks associated with:

• Nitrate

Requirements

(a) to maintain the following measures for the period specified [in each case]:

1. Regular review and update of groundwater risk assessments.
   Date: Ongoing for the duration of the notice
2. Nitrate exceedance prediction graphs will be regularly updated, and nitrate will be assessed as a hazard as part of the Regulation 27 risk assessment for the supply system supplied by Gayton WTW according to a Drinking Water Safety Planning approach.
   Date: Ongoing for the duration of the notice
3. The existing blending option of the higher nitrate sources with the lower nitrate sources within the West Norfolk – Marham/ Bexwell supply system, will be optimised to ensure continued compliance, until the completion of the additional control measures.
   Date: Ongoing for the duration of the notice
4. Operational and regulatory monitoring for nitrate at the raw water, final water at Gayton WTW and in the downstream Public Water Supply Zones.
   Date: Ongoing for the duration of the notice
5. Exceedances investigated in line with company procedures.
   Date: Ongoing for the duration of the notice

(b) to review, revise and/or make operational the following measures, by the date specified below:

1. Short term measures
   • Make operational with immediate effect and maintain until revocation of this notice the short-term measures identified below.
     Date: Ongoing for the duration of the notice
     • Implement an enhanced monitoring strategy for nitrate to include the monitoring of all high-risk water sources and associated final waters on a weekly basis to supplement the current regulatory treated water monitoring.
     • Report all exceedances of the nitrate parameter to the Local Authority and Health Protection team and agree further additional steps to protect public health as appropriate.
     • Report all regulatory exceedances of the standards for the nitrate parameter to DWI as part of the current monthly exception reporting process.
2. Medium term measures
   • Make operational and maintain the medium term measures identified below;
     • Carry out more intensive investigation to provide further information to confirm steps to be taken and project completion dates.
       Date: 31 December 2021
     • Complete planning, design, and procurement arrangements to provide Ion Exchange treatment at Gayton WTW.
       Date: 31 December 2022
     • Complete construction, installation, and commissioning of an Ion Exchange plant at Gayton WTW.
       Date: 31 December 2023
3. Long term measures
   • Make operational and maintain for the duration of this notice the long-term measures identified below;
     Date: Ongoing for the duration of the notice
     • Continue to review at regular intervals the nitrate exceedance prediction graphs and trend data to inform and alter where necessary operational delivery of this programme.
     • Continue catchment management initiatives. Support any voluntary initiatives to influence nitrate usage in the catchments upstream of Gayton WTW, taking a risk based approach. Engage with and provide data to the Environment Agency and other relevant stakeholders as required on a regular basis.
     • Continually appraise the risk of nitrate as a hazard as part of the Regulation 27 risk assessment for the supply systems supplied by Gayton WTW according to a Drinking Water Safety Planning approach, and ensure that Regulation 28 documents are regularly reviewed and updates provided as necessary.

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

1. Define a strategy for auditing the effectiveness of the above measures by 30 September 2020;
   Date: Complete
   • Monitoring for nitrate at all high risk raw water sources feeding Gayton final water point on a weekly basis, throughout the implementation of the short, medium and long term measures.
   • Continue to monitor nitrate at an enhanced frequency for a period of 12 months following commission of the work outlined above. Investigation of any unusual results.
   • The audit strategy for the Ion Exchange treatment will be determined through risk assessment after the completion of the works.

(d) not to supply water for regulation 4(1) purposes from Gayton WTW unless the conditions specified below are satisfied:

N/A

(e) to provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risk of supplying water that would constitute a potential danger to human health:

1. Provide a progress report annually by 31 January and against the following milestones: this will be ongoing for the duration of the notice.
   Date: Annually by 31 January
2. The company shall provide an overview of its operational strategy for maintaining nitrate below the standard prescribed by the Water Supply (Water Quality) regulations 2016 (as amended)
   Date: Complete
3. A statement to confirm the completion of investigations to provide further information to confirm steps to be taken and project completion dates.
   Date: 31 January 2022
4. A statement to confirm completion of the planning, design, and procurement arrangements
   Date: 31 January 2023
5. A statement to confirm completion of construction, installation, and commissioning of an Ion Exchange plant at Gayton WTW.
   Date: 31 January 2024
6. Submit a report regarding the audit/monitoring strategy for the demonstration of benefit phase;
   Date: Complete
7. Review the risk assessment for Gayton WTW as required by Regulation 27(4) or 28(4) and subsequently submit a revised regulation 28 report accompanied by board level director sign off (approx. 2 months after completion of the work)
   Date: 28 February 2024
8. Submit a satisfactory completion report.
   Date: 31 January 2025

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Failure by the company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991.

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Signed by authority of the Secretary of State
Laura Moss
Deputy Chief Inspector
20 July 2021
DWI Reference: ANH-2018-00004
Version 2