South West Water Limited – Clevedon Water Treatment Works

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

Reference: BRL 4092

Version Number: 6

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): South West Water Limited, with registered number 02366665 (hereinafter called ‘the Company’).

Assets Affected:

  • Clevedon Water Treatment Works T09
  • Clevedon Supply System Y07

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 26 January 2022, which states that there is or has been a significant risk of supplying water from Clevedon Water 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 I D



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.


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

  1. That Clevedon works remains out of supply until the risks associated with Cryptosporidium are mitigated. Before Clevedon works is returned to supply by the date listed in the notice, or earlier, an application under regulation 15 should be made to the Inspectorate.
    Date: Complete.

(b) To review, revise or make operational the following measures, by the dates specified in each case:

  1. Install and commission a validated UV system which meets the requirements of DWI Guidance and is suitable for the inactivation of Cryptosporidium oocysts.
    Date: 31 December 2023.
  2. Provide appropriate training for all staff who will be required to operate or maintain or interpret data associated with the UV treatment stage at Clevedon works.
    Date: 31 January 2023.

(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: Complete.
  2. Implement, and keep under continuous review, the audit strategy defined in requirement 1, section (c) and the measures outlined below as ongoing from the date that the UV system is made operational:The UVT and turbidity of the water at the inlet to the UV reactor(s) to be monitored and recorded continuously with suitable alarms and shutdowns.
    • The UVT and turbidity of the water at the inlet to the UV reactor(s) to be monitored and recorded continuously with suitable alarms and shutdowns.
    • The UV intensity to be monitored and recorded continuously with suitable alarms and shutdowns.
    • A validated UV dose of at least 40 mJ/cm2 will be maintained at all times with suitable alarms and shutdowns.
    • All UV system equipment will be maintained and operated in line with the manufacturers and company specifications.
      Date: Following completion of measure (c)1. onwards.

(d) Not to supply water for regulation 4(1) purposes from Clevedon Water Treatment Works, or not to so supply unless the specified conditions below are satisfied:

  1. Clevedon works to remain out of supply until completion of requirement (b)1.
    Date: 31 December 2023.

(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. Outline design and tender preparations.
    Date: Complete.
  3. Tender issue, evaluation, and contract awarded.
    Date: Complete.
  4. Provide a report confirming completion of the installation and commissioning of a validated UV system at Clevedon works, as required in measure (b)1.
    Date: 31 January 2024.
  5. Submit a risk assessment report under regulation 15 (1)(b) for Clevedon WTW raw water for a source that has not been used for 6 months preceding the date that the company intend to supply water from it.
    Date: Complete.
  6. Provide a report evidencing the implementation of training of relevant staff with the UV system at Clevedon works, as required in measure (b)2.
    Date: 28 February 2024.
  7. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: Complete.
  8. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision.
  9. 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.
  10. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 31 January 2025.

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.


Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
10 October 2023
Reference: BRL 4092 V6

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