Notice of regulation: Southern Water Services Limited – Weirwood Forest Row Treatment Works New Build 

Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

Southern Water Services Limited – Weirwood Forest Row Treatment Works

Reference: SRN-2022-00002

Version Number: 1

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Southern Water Services Limited, with registered number 02366670 (hereinafter called ‘the Company’).

Assets Affected:

  1. TS009 – Weirwood Forest Row WSW
  2. Y040 – Weirwood Forest Row Supply System

Details of this Notice:

  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 19 November 2018, which states that there is or has been a significant risk of supplying water from Weirwood Forest Row WSW (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:

Description of Risk

Hazard/ Hazardous Event/ Parameter

Hazard I D

Ingress route and failure of treatment process

Pathogenic Bacteria

47073 (Clostridium perfingens),

47076 (E. coli),

47077 (Enterococci),

47075 (Total coliforms)

Catchment risks and failure of treatment process

Parasites

47972 (Cryptosporidium)

Insufficient water supply to downstream consumers

No Supply

47131, 47132, 47133

Failure of treatment poses risk to wholesomeness

Taste and Odour

47123, 47124

Failure of treatment poses risk to wholesomeness

pH

47127

Catchment risks and failure of treatment process

Pesticides

47087

Failure of treatment poses risk to wholesomeness

Chemical (public health hazard)

47130 (physio-chemical)

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
  1. The Company are 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:

  1. Continue progressing the Sussex North schemes in order to support the Water Hardham WSW supplies to customers in the Sussex North Resource Zone while the new treatment stream at Weirwood WSW is being built.
    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. Complete investigation into draw-off tower valves and agree corrective actions.
    Date: Complete
  2. Complete corrective actions as outlined in (b)1. and commission valve actuators.
    Date: 30 June 2022
  3. Complete the detailed design of the Water Supply Works the Company has chosen to build, including timelines.
    Date: 31 August 2022
  4. Confirm the programme of works for the new Weirwood WSW, including the programme for completion of:
    • Construction
    • Commissioning
    • Asset Integration
    • Training of operational staff
      Date: 31 October 2022
  5. Disconnect and make safe the old equipment and decommission redundant equipment as required, based on the detailed design.
    Date: 30 June 2023
  6. Confirm the completion of the following at Weirwood WSW:
    • Construction of the new water treatment processes
    • Commissioning of new water treatment processes
    • Asset Integration of new water treatment processes
    • Training of operational staff on the new operation and maintenance of the new water treatment processes
    • Supply of water from Weirwood WSW into the downstream supply network.
      Date: 31 March 2025

(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 sections (a) and (b).
    Date: 30 April 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 Weirwood Forest Row WSW,

  1. Until such time the company confirms the risk from the biological growth observed at the treatment works is mitigated.

(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:
  2. Complete the corrective actions identified during the investigations into draw off tower valves.
    Date: 31 July 2022
  3. Submit detailed design to the Inspectorate.
    Date: 30 September 2022
  4. Provide the programme of works for the new Weirwood WSW, including the programme for completion of:
    • Construction
    • Commissioning
    • Asset Integration
    • Training of operational staff
      Date: 30 November 2022
  5. Confirmation the old site has been disconnected and made safe, and decommissioned some of the redundant equipment, as required.
    Date: 31 July 2023
  6. Submit application as per Regulation 15 (1) (a) before bringing supply back to work. To include evidence confirming biological growth is no longer a risk.
    Date: 1 month prior to returning to supply
  7. Provide an update on progress against the confirmed programme of works in (b)4. at 6 monthly intervals from the date of submission of the programme.
    Date: At a frequency of six months from (b)4.
  8. Confirm the completion of the following at Weirwood WSW:
    • Construction of the new water treatment processes
    • Commissioning of new water treatment processes
    • Asset Integration of new water treatment processes
    • Training of operational staff on the new operation and maintenance of the new water treatment processes
    • Supply of water from Weirwood WSW into the downstream supply network
    • Provide a confirmation the site was run into supply
      Date: 30 April 2025
  9. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 31 May 2022
  10. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  11. 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
  12. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 April 2026

Further Details of this Notice:

  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).
  4. Contravention of a regulation 28(4)(d) requirement is an offence under regulation 33(1). If guilty of such an offence, the Company is liable on summary conviction, or on conviction on indictment, to a fine. Under regulation 33(2) it is a defence for the Company to show that it took all reasonable steps and exercised all due diligence to avoid the commission of the offence.

Signed

Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
28 February 2022
Reference: SRN-2022-00002 (V1)

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