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Notice of Regulation: Iver treatment Works

Completion Date: 31/01/2029
Ref: AFW-2020-00005

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

Affinity Water Limited: Iver Treatment Works

Reference: AFW-2020-00005
Version Number: 1
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:
Iver Treatment Works TR383

  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 2020, which states that there is or has been a significant risk of supplying water from Iver Treatment Works (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

Cryptosporidium oocysts (confirmed)

AFW-TR383-BACC111-CRYPTO

Cryptosporidium risk from the raw water catchment

  1. The Company are required to satisfy the following requirements:

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

  1. Operate Iver treatment works in accordance with Company policy, procedures and to internally agreed process parameters.
    Date: Ongoing for the duration of this Notice
  2. Continue to monitor the raw water, including cryptosporidium, at the current frequencies (daily for cryptosporidium) and in accordance with the Company’s procedures, in order to understand and assess the raw water quality risk posed.
    Date: Ongoing for the duration of this Notice
  3. Continue to monitor the final water, including continuous monitoring for cryptosporidium, at the current frequencies and in accordance with the Company’s procedures.
    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. Conduct a review into the catchment risks and additional treatment options to mitigate cryptosporidium risks at Iver treatment works.
    Date: Complete
  2. The Company shall monitor for tryptophan on the River Thames upstream of the intake for Iver treatment works.
    1. Install online monitoring on the River Thames up-stream of the intake for Iver treatment works.
      Date: Complete
    2. Review the tryptophan monitoring data and confirm how this data will be used to understand water quality in the River Thames.
      Date: 31 October 2021
    3. Produce a report on the findings of this review step (b)2.1 and confirm the details of the Company’s procedure for responding to increased levels of tryptophan recorded by the online monitor.
      Date: 30 November 2021
  3. Design additional treatment options, or modifications to existing treatment, for Iver treatment works, to include:
    1. Validated UV irradiation treatment for the inactivation of Cryptosporidium oocysts.
      Date: 30 June 2021
    2. Optimisation of the clarification process.
      Date: 30 November 2024
    3. Additional rapid gravity filters to treat the full output at Iver treatment works.
      Date: 30 November 2024
    4. Covers for the GAC filters.
      Date: 30 November 2024
    5. The upgrade of the wastewater treatment plant to improve water recirculating to the head of the works.
      Date: 30 November 2024
  4. Construct, commission and provide training for additional treatment options, or modifications to existing treatment, for Iver treatment works, to include:
    1. Validated UV irradiation treatment for the inactivation of Cryptosporidium oocysts.
      Date: 31 December 2023
    2. Optimisation of the clarification process.
      Date: 31 December 2027
    3. Additional rapid gravity filters to treat the full output at Iver treatment works.
      Date: 31 December 2027
    4. Covers for the GAC filters.
      Date: 31 December 2027
    5. The upgrade of the wastewater treatment plant to improve water recirculating to the head of the works.
      Date: 31 December 2027
  5. Conduct a review and consult with the Environment Agency to consider options for containment or run to waste and discharge at each process stage at Iver treatment works.
    Date: 31 December 2023
  6. Identify solutions for containment, run to waste and discharge options at each process stage at Iver treatment works.
    Date: 31 December 2027

(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: 3 months after Notice served date
  2. Implement, and keep under continuous review, the audit strategy defined in measure (c)1.Following completion of measure (c)1.
    Date: onwards

(d) not to supply water for regulation 4(1) purposes from Iver 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:

  1. Provide a progress report annually by 31 January and against the following milestones:
    Date: Annually by 31 January
    1. Confirm the details of the strategy for auditing the effectiveness of the measures as specified in section (c).
      Date: 3 months after Notice served date
    2. Submit a report on the Company’s findings following tryptophan monitoring in the River Thames, as per step (b)2.3.
      Date: 30 November 2021
    3. Confirm the solutions identified and completion of the design, as identified in step (b)3.1.
      Date: 31 July 2021
    4. Confirm the solutions identified and completion of the design, as identified in steps (b)3.2 to (b)3.5.
      Date: 31 December 2024
    5. Confirm the completion of the installation, commissioning and training of Site Operators for the UV irradiation treatment as identified in step (b)4.1.
      Date: 31 January 2024
    6. Confirm the completion of the installation, commissioning and training of Site Operators for the additional treatment options or modifications to existing treatment, as identified in steps (b)4.2 to (b)4.5.
      Date: 31 January 2028
  2. Submit an interim report on the progress of the Notice, to include a 12-month demonstration of benefit period following the completion of the UV irradiation treatment as identified in step (b)4.1.
    Date: 30 April 2025
  3. Submit a report in the event that any completed measure of this Notice needs to be altered in any way for any reason.
    Date: When required
  4. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 31 January 2029 (13 months after completion of period of demonstration of benefit phase)
  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
Laura Moss
Deputy Chief Inspector, on behalf of the Secretary of State for Environment,
Food and Rural Affairs
16 December 2020
Reference: AFW-2020-00005