Anglian Water Services Limited – Buckingham Water Supply Zone
Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)
Reference: ANH-2022-00006
Version Number: 3
Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Anglian Water Services Limited, with registered number 02366656 (hereinafter called ‘the company’).
Assets Affected:
- Deanshanger Reservoir 1 – RDER1
- Deanshanger Reservoir 2 – RDER2
- Maidford Reservoir – RMAR0
- Buckingham WSZ – ZRW20
- Ruthamford Supply system – YRUT
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 1 September 2022, which states that there is or has been a significant risk of supplying water to Buckingham WSZ (and associated assets as applicable) 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:
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.
Description of Risk | Hazard/ Hazardous Event/ Parameter | Hazard I D |
|---|---|---|
Deanshanger Service Reservoir 1 | ||
Booster disinfection failure at SP (hypo) (PCV breach) | Clostridium Perfringens (Sulphate-reducing Clostridia) (confirmed) Total Coliforms (Confirmed) E. coli (faecal coliforms Confirmed) | ANH-RDER1-C004A-ST0095 ANH-RDER1-C001-ST0111 ANH-RDER1-C002-ST0182 |
Operational Risk | Total Coliforms (Confirmed) E. coli (faecal coliforms Confirmed) | ANH-RDER1-C001-ST0914 ANH-RDER1-C002-ST0916 |
Low CL Residual (WQ Incident) | Total Coliforms (Confirmed) | ANH-RDER1-C001-ST0905 |
Baseline Risk | Total Coliforms (Confirmed) E. coli (faecal coliforms Confirmed) | ANH-RDER1-C001-ST0931 ANH-RDER1-C002-ST0933 |
Deanshanger Service Reservoir 2 | ||
Booster disinfection failure at SP (hypo) (PCV breach) | Clostridium Perfringens (Sulphate-reducing Clostridia) (confirmed) Total Coliforms (Confirmed) E. coli (faecal coliforms Confirmed) | ANH-RDER2-C004A-ST0095 ANH-RDER2-C001-ST0111 ANH-RDER2-C002-ST0182 |
Baseline risk | Total Coliforms (Confirmed) E. coli (faecal coliforms Confirmed) | ANH-RDER2-C001-ST0931 ANH-RDER2-C002-ST0933 |
Operational risk | Total Coliforms (Confirmed) E. coli (faecal coliforms Confirmed) | ANH-RDER2-C001-ST0914 ANH-RDER2-C002-ST0916 |
Low CL residual (WQ Incident) | Total Coliforms (Confirmed) | ANH-RDER2-C001-ST0905 |
Maidford Service Reservoir | ||
Baseline risk | Clostridium Perfringens (Sulphate-reducing Clostridia) (confirmed) | ANH-RMAR0-C004A-ST0974 |
Failure at Upstream asset (PCV breach) | Total Coliforms (Confirmed) | ANH-RMAR0-C001-ST0115 |
Low CL residual (WQ Incident) | Total Coliforms (Confirmed) | ANH-RMAR0-C001-ST0905 |
Operational risk | Total Coliforms (Confirmed) E. coli (faecal coliforms Confirmed) | ANH-RMAR0-C001-ST0914 ANH-RMAR0-C002-ST0916 |
Regrowth (PCV breach) | E. coli (faecal coliforms Confirmed) | ANH-RMAR0-C002-ST0193 |
Baseline risk | Total Coliforms (Confirmed) E. coli (faecal coliforms Confirmed) | ANH-RMAR0-C001-ST0913 ANH-RMAR0-C002-ST0933 |
Buckingham PWSZ | ||
Baseline risk | Clostridium Perfringens (Sulphate-reducing Clostridia) (confirmed) Coliform Bacteria (Indicator) E. coli (faecal coliforms Confirmed) | ANH-ZRW20-C004A-DI1115 ANH-ZRW20-C001A-DI1072 ANH-ZRW20-C002-DI1074 |
Failure at Upstream asset (PCV breach) | Clostridium Perfringens (Sulphate-reducing Clostridia) (confirmed) Coliform Bacteria (Indicator) | ANH-ZRW20-C004A-DI0098 ANH-ZRW20-C001A-DI0110 |
Operational Risk | Coliform Bacteria (Indicator) E. coli (faecal coliforms Confirmed) | ANH-ZRW20-C001A-DI1059 ANH-ZRW20-C002-DI1061 |
Low CL Residual (WQ Incident) | Coliform Bacteria (Indicator) | ANH-ZRW20-C001A-DI1042 |
Repaired main (PCV Breach) | Coliform Bacteria (Indicator) E. coli (faecal coliforms Confirmed) | ANH-ZRW20-C001A-DI0119 ANH-ZRW20-C002-DI0188 |
Mains rehabilitation work (PCV Breach) | Coliform Bacteria (Indicator) E. coli (faecal coliforms Confirmed) | ANH-ZRW20-C001A-DI0117 ANH-ZRW20-C002-DI0186 |
Low CL residual (PCV Breach) | Coliform Bacteria (Indicator) E. coli (faecal coliforms Confirmed) | ANH-ZRW20-C001A-DI0114 ANH-ZRW20-C002-DI0183 |
Regrowth (PCV Breach) | Coliform Bacteria (Indicator) E. coli (faecal coliforms Confirmed) | ANH-ZRW20-C001A-DI0118 ANH-ZRW20-C002-DI0187 |
Burst Main (PCV Breach) | Coliform Bacteria (Indicator) E. coli (faecal coliforms Confirmed) | ANH-ZRW20-C001A-DI0105 ANH-ZRW20-C002-DI0174 |
Depressurisation (PCV Breach) | Coliform Bacteria (Indicator) E. coli (faecal coliforms Confirmed) | ANH-ZRW20-C001A-DI0107 ANH-ZRW20-C002-DI0176 |
- The company is 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:
- Maintain target network chloramine residuals within Buckingham PWSZ
Date: Ongoing for the duration of this notice - Ensure continued operation of Deanshanger Service reservoir chloramination booster station at target set points.
Date: Ongoing for the duration of this notice - Periodically complete chlorine decay testing to monitor effectiveness of mains conditioning as part of validating planned proactive maintenance within Buckingham PWSZ, at frequency defined in the audit strategy.
Date: Ongoing for the duration of this notice - Complete enhanced sampling of Buckingham PWSZ to monitor bacteriological concentrations within network, as defined in the audit strategy.
Date: Ongoing for the duration of this notice - Continue to work with HS2 depots supplied from the Buckingham PWSZ to ensure usage and hydrant activity is not having a negative impact on the supply to consumers. Ensure other third-party use of the network is done responsibly by trained operatives with the correct equipment.
Date: Ongoing for the duration of this notice - Maintain locking caps on washouts and hydrants where caps are determined necessary.
Date: Ongoing for the duration of this notice - Maintain suitable pump control settings at Thorpe Lodge WR to ensure the necessary amount of water is supplied to Buckingham PWSZ at periods of high demand.
Date: Ongoing for the duration of this notice - Maintain optimised amendments to pump control at Livingstone Lovell boosters to ensure reduced pressures within the localised network at Maidford service reservoir.
Date: Ongoing for the duration of this notice - Maintain effective communication plan for consumers and stakeholders within Buckingham PWSZ whilst noticed deliverables completed.
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:
Air Entrapment and Pressure Solutions
- Implement remedial solutions to prevent air entrapment from pressure effects during high demand periods within the Buckingham PWSZ.
Date: Complete - Review the current pressure sustaining valve arrangements on HS2 compound connections and determine whether further work is required to protect the network from depressurisation risks. The review is to include performance during the summer demand period 2023.
Date: Complete - Complete optimisation investigation of Thorpe Lodge boosters within Buckingham PWSZ.
Date: Complete - Following (b)3. determine action plan for Thorpe Lodge Boosters to ensure suitable pump control settings to maintain necessary amount of water in Buckingham PWSZ at periods of high demand.
Date: Complete - Following (b)4. implement action plan for Thorpe Lodge Boosters.
Date: Complete - Deliver the connection of two reinforcement mains to protect the Buckingham PWSZ network from additional demand caused by HS2 construction activities.
Date: Complete
Proactive Planned Maintenance and Mains Enhancements
- Develop a proactive planned maintenance mains conditioning and flushing programme for the Boddington DMA, Weedon Lois DMA, Maidford DMA and the main upstream of Maidford storage reservoir, within the Buckingham PWSZ.
Date: Complete - Deliver a proactive planned maintenance mains conditioning and flushing programme for the Boddington DMA, Weedon Lois DMA, Maidford DMA and the main upstream of Maidford storage reservoir, within the Buckingham PWSZ. developed in (b)7.
Date: Complete - Determine appropriate mains cleaning technique for outlet mains on Maidford service reservoir.
Date: Complete - Following completion of (b)9. deliver mains cleaning and mains replacement/rehabilitation on the outlet mains on Maidford service reservoir.
Date: Complete - Review the suitability of asbestos cement main material used within the Buckingham PWSZ in relation to the risk of burst mains and consequences from high ambient temperatures and high soil moisture deficit.
Date: Complete - Following delivery of (b)11. identify sections of asbestos cement main for renewal within Buckingham PWSZ.
Date: Complete - Deliver renewal of asbestos cement mains identified in step (b)12. within Buckingham PWSZ. Deliver renewal of cast iron main section downstream of the Lillingstone Lovell Booster.
Date: 31 March 2026 - Evaluate the main diameters at the high elevations within the Buckingham PWSZ and whether mains abandonment or downsizing is required.
Date: Complete - Following delivery of (b)14. identify sections of main for downsizing or abandonment.
Date: Complete
Maintaining Network Residual
- Deliver an upgraded Chloramination booster station at Deanshanger service reservoir to maintain a suitable network residual and prevent biofilm growth within Buckingham PWSZ and Maidford Service Reservoir. Installation of booster chloramination should operate on residual control rather than current set point dose.
Date: Complete - Update the 2014 network modelling to determine the age of water in the Deanshanger service reservoirs (1 and 2), Maidford service reservoir and across the Buckingham PWSZ.
Date: Complete - Undertake a review of the chloramine residuals in the Deanshanger service reservoirs (1 and 2), Maidford service reservoir and across the Buckingham PWSZ. Taking into account any improvement in chloramine residuals following the delivery of the mains conditioning and flushing activities and the upgrading of Deanshanger booster chloramination.
Date: Complete - Complete an appraisal of outcomes from delivery of (b)17. and (b)18. And determine whether any further remedial actions are required to maintain water quality within the Buckingham PWSZ. Provide plan of work for actions.
Date: Complete - Deliver remedial actions as defined by (b)19. if required.
Date: 31 March 2025
(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: Complete - 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 to Buckingham PWSZ, 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. - Provide report evidencing all milestones completed by 31 December 2022, including completed measures prior to notice being served.
Date: Complete - Provide report evidencing all milestones completed by 31 March 2023
Date: Complete - Provide report evidencing all milestones completed by 31 May 2023
Date: Complete - Provide report evidencing all milestones completed by 31 October 2023
Date: Complete - Provide report evidencing all milestones completed by 30 November 2023
Date: Complete - Provide report evidencing all milestones completed by 31 March 2024
Date: Complete - Provide report evidencing all milestones completed by 31 March 2025
Date: 30 April 2025 - Provide report evidencing all milestones completed by 31 March 2026
Date: 30 April 2026 - Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
Date: Complete - 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 a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
Date: 30 April 2027
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).
Signed
Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
31 October 2024
Reference: ANH-2022-00006 V3