Southern Water Services Limited – AMP8 Disinfection Resilience Programme, Cryptosporidium

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

Reference: SRN-2023-00016

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:

  • Twyford WSW – TH005
  • Patcham WSW – TS033
  • Burpham WSW – TS017
  • Southampton East Supply System – Y013
  • Brighton Supply System – Y007
  • Worthing Supply System – Y009

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 31 March 2023, which states that there is or has been a significant risk of supplying water from Twyford WSW, Patcham WSW and Burpham WSW (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
  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 ID

Raw water deterioration, as indicated by the presence of Cryptosporidium and other faecal indicators.

Cryptosporidium

30084


44282


48994

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. Carry out enhanced monitoring for Total Coliforms, E.coli, Enterococci and Cryptosporidium on the raw and treated water as defined in the audit strategy.
    Date: Ongoing for the duration of this Notice
  2. Maintain operation of all processes at each of the Water Supply Works within defined operating ranges and ensure control and shutdown systems are operational.
    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. Twyford WSW:
    a) Confirm scope of additional Cryptosporidium mitigation measures.
    The current notional solution is new UV Treatment Plant.
    Date: 30 September 2027
    b) Install and commission additional Cryptosporidium mitigation measures.
    Date: 31 March 2030
  2. Burpham WSW:
    a) Confirm scope of additional Cryptosporidium mitigation measures.
    The current notional solution is new UV Treatment Plant.
    Date: 30 September 2027
    b) Install and commission additional Cryptosporidium mitigation measures.
    Date: 31 March 2030
  3. Patcham WSW:
    a) Confirm scope of additional Cryptosporidium mitigation measures.
    The current notional solution is new UV Treatment Plant.
    Date: 30 September 2027
    b) Install and commission additional Cryptosporidium mitigation measures.
    Date: 31 March 2030

(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: 31 March 2024
  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 Twyford WSW, Burpham WSW or Patcham WSW, or not to so supply unless the specified conditions below are satisfied:

  1. 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.
    Date: by 31 January each year.
  2. Provide a report confirming the scope of additional Cryptosporidium mitigation measures at Twyford WSW.
    Date: 31 October 2027
  3. Provide a report confirming the scope of additional Cryptosporidium mitigation measures at Burpham WSW.
    Date: 31 October 2027
  4. Provide a report confirming the scope of additional Cryptosporidium mitigation measures at Patcham WSW.
    Date: 31 October 2027
  5. Provide a report confirming the completion of the installation and commissioning of additional Cryptosporidium mitigation measures at Twyford WSW.
    Date: 30 April 2030
  6. Provide a report confirming the completion of the installation and commissioning of additional Cryptosporidium mitigation measures at Burpham WSW.
    Date: 30 April 2030
  7. Provide a report confirming the completion of the installation and commissioning of additional Cryptosporidium mitigation measures at Patcham WSW.
    Date: 30 April 2030
  8. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 30 April 2024
  9. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  10. 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
  11. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 April 2031

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).

Signed

Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
7 February 2024
Reference: SRN-2023-00016 v1

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