Severn Trent Water Limited – AMP8 Witches Oak PFAS

Water Industry Act 1991 (as amended) (“the Act”): Section 19(1)(b)

Reference: SVT-2023-00007

Acceptance Notice:

The Drinking Water Inspectorate, on behalf of the Secretary of State for Environment, Food and Rural Affairs:

  1. Is satisfied that Severn Trent Water Limited “the Company” in supplying water from Witches Oak water treatment works which may be at risk of breaching the wholesomeness standard due to PFAS concentrations. This means that the Company is likely to contravene its duty in respect of supplying water which meets the Regulations under Section 68(1)(a) of the Water Industry Act 1991 and meets the requirement set in regulation 4(2)(c) of the Water Supply (Water Quality) Regulations 2016 (as amended) (“the Regulations”).
  2. Has notified the Company on 30 August 2023 that the Secretary of State is considering making in relation to the company an enforcement order under Section 18 of the Act.
  3. Notes that the Company has on 21 March 2024 given a new undertaking under Section 19 (1) (b) of the Act, to take the following steps by the dates shown.

Steps to be taken:

  1. Ensure that the relevant PFAS parameter(s) have been assessed as hazards as part of the regulation 27 Risk Assessments for the supply system supplied by Witches Oak water treatment works according to a Drinking Water Safety Plan approach.
    Date: At least 1 month before water is put into supply
  2. Utilizing a risk based monitoring frequency, sampling at raw water sample points and at points which from time to time form part of investigatory treatment trials.
    Date: Ongoing for the duration of the Undertaking
  3. Continue to improve competency of relevant operational staff, in particular regarding the identification and management of risk relating to drinking water quality.
    Date: Ongoing for the duration of the Undertaking
  4. Regularly appraise PFAS risk and update the regulation 27 risk assessments accordingly.
    Date: Ongoing for the duration of the Undertaking
  5. Maintain catchment investigations and catchment management for the new Witches Oak catchment.
    Date: Ongoing for the duration of the Undertaking
  6. Confirm the proposed solution type for PFAS treatment at Witches Oak WTW based on investigations and pilot plant trials.
    Date: 31 May 2025
  7. Complete outline design of the proposed solution and provide estimated start date for construction.
    Date: 31 January 2027
  8. Provide expected completion date for the solution.
    Date: 31 January 2027
  9. Complete construction and commissioning of the solution.
    Date: 31 August 2028
  10. Define an audit strategy to monitor the effectiveness of the measures specified above.
    Date: 31 May 2024
  11. Implement, and keep under continuous review, the audit strategy defined in measure 10.
    Date: Following completion of measure 10.

Reporting:

  1. Provide a progress report annually.
    Date: 31 January each year
  2. Confirm the proposed solution for PFAS treatment at Witches Oak WTW based on investigations and pilot plant trials.
    Date: 30 June 2025
  3. Confirm completion of outline design and expected start date for construction of the solution.
    Date: 28 February 2027
  4. Confirm commencement of construction of the solution.
    Date: 28 February 2027
  5. Confirm completion of construction and commissioning of the solution.
    Date: 30 September 2028
  6. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (d)1.
    Date: 30 June 2024
  7. Submit any revisions of the audit strategy produced under measure (d)1.
    Date: Within 1 month of a revision
  8. Submit a report in the event that any completed measures of this Undertaking need to be altered in any way, for any reason.
    Date: Ongoing for the duration of the undertaking
  9. Provide a final report to the Inspectorate on the efficacy of the steps taken as part of this undertaking, accompanied by a revised regulation 28(1) report with Board level Director sign-off. Include, as evidence of closure for this scheme, appropriate documentation to confirm that the actions set out in this Schedule of Work have been completed satisfactorily.
    Date: 30 September 2029

Further Details of this Acceptance Notice:

  1. The Secretary of State is satisfied that Severn Trent Water Limited has given and is complying with an undertaking to take all such steps as appear to the Secretary of State for the time being to be appropriate to secure or facilitate compliance with the requirement of regulation 4(2)(c) of the Water Supply (Water Quality) Regulations 2016 (as amended).

Authorised by the Secretary of State to sign in that behalf

Nicholas Adjei
Deputy Chief Inspector, Drinking Water Inspectorate
8 April 2024
Reference: SVT-2023-00007 v1

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