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Notice of Regulation: Hitchin Disinfection

NOTICE UNDER REGULATION 28(4) OF THE WATER SUPPLY (WATER QUALITY) REGULATIONS 2016 (AS AMENDED)

Affinity Water Limited: Hitchin Disinfection

Reference: AFW-2021-00004
Version Number: V1

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Affinity Water Limited, with registered number 02546950 (hereinafter called ‘the Company’).

Assets affected:TL374 Windmill Hill

  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 01 October 2021, which states that there is or has been a significant risk of supplying water from Windmill Hill WTW (and associated assets as applicable) that could constitute a potential danger to human health.
  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:

Hazard/Hazardous

Event/Parameter

Hazard ID

Description of Risks

Microbiological

Failure of treatment

Failure to disinfect

AFW-TL374-NSTH033-FAILTR

AFW-TL374-NSTH033-FLDISI

Failure to meet requirements of Regulation 26, inadequate disinfection, due to a failure to demonstrate that disinfection contact time is met under all conditions.

Residual Disinfectant- Free

Residual Disinfectant- Total

Microbiological

  1. The Company are required to satisfy the following:

Requirements

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

  1. Optimisation of all existing treatment processes.
    Date: Ongoing for the duration of this notice.
  2. Operation of all process within defined normal operating ranges with appropriate triggers, responses, and contingency procedures.
    Date: Ongoing for the duration of this notice.
  3. Online turbidity and chlorine monitoring with appropriate alarms and failsafe shutdowns.
    Date: Ongoing for the duration of this notice.
  4. Continue regulatory monitoring for bacteriological parameters and ensure that documented procedures for the escalation and investigation of any deviation from expected results.
    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. The Company shall undertake an investigation of the existing disinfection system and confirm a programme of work to allow verification of disinfection under all circumstances and flow rates and include the following:
    Date: 31 March 2022
    1. The point in the treatment process whereby disinfection is achieved (the point of disinfection) must be clearly defined.
    2. The final sample point must be located at the end of the treatment process and be representative of water leaving the treatment process.
    3. The disinfection system must provide safeguards such as automatic shutdown or failsafe systems to prevent untreated or partially treated water entering into supply.
  2. Install and commission the chosen disinfection system as defined by (b)1 and ensure that it is sufficient to disinfect the water supplied from Windmill Hill WTW.
    Date: 31 December 2022
  3. Install and commission sufficient monitoring equipment to continuously verify the effectiveness of the disinfection process installed in (b)2.
    Date: 31 December 2022
  4. Review the site-specific disinfection policy with associated site-specific procedures and report revisions of the document to the Inspectorate.
    Date: 31 December 2022
  5. Update the Site Operating Manual and remove all out-of-date material from circulation.
    Date: 31 December 2022
  6. Provide adequate training to operators as commissioning process and for any revision of the Site Operating Manual completed under Requirement (b)4.
    Date: 31 December 2022

(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 section (a) and (b).
    Date: 28 February 2022
  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 Windmill Hill WTW, or not to so supply unless the specified conditions below are satisfied:

Not Applicable 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 risks:

  1. Provide a progress report annually by 31 January and against the following milestones:
    Date: Annually by 31 January
    1. The Company shall undertake an investigation of the existing disinfection system and confirm a programme of work to provide adequate disinfection under all circumstances and flow rates.
      Date: 30 April 2022
    2. Install and commission the chosen disinfection system as defined by (b)1 and ensure that it is sufficient to disinfect the water supplied from Windmill Hill WTW.
      Date: 31 January 2023
    3. Install and commission sufficient monitoring equipment to continuously verify the effectiveness of the disinfection process installed in (b)2.
      Date: 31 January 2023
    4. Review the site-specific disinfection policy with associated site-specific procedures and report revisions of the document to the Inspectorate.
      Date: 31 January 2023
    5. Update the Site Operating Manual and remove all out-of-date material from circulation.
      Date: 31 January 2023
    6. Provide adequate training to operators as commissioning process and for any revision of the Site Operating Manual completed under Requirement (b)4.
      Date: 31 January 2023
  2. Submit the strategy for auditing the effectiveness of the measures, as specified in (c)1.
    Date: 31 March 2022
  3. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision to the strategy
  4. Submit a report in the event that any completed measure of this Notice needs to be altered in any way for any reason.
    Date: Ongoing for the duration of this Notice
  5. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 31 January 2024
  1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
  2. 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.
  3. 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
Nick Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
13 December 2021
Reference: AFW-2021-00004

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