Severn Trent Water Limited – Strensham Contact Tank Improvement Scheme

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

Reference: SVT-2019-00005

Version Number: 3

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Severn Trent Water Limited, with registered number 02366686 (hereinafter called ‘the Company’).

Assets Affected:

  • T0118 Strensham works

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 29 May 2018, which states that there is or has been a significant risk of supplying water from Strencham Works (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:

Hazard/ Hazardous Event/ Parameter

Hazard I D

Escherichia coli (E. coli)


Coliform bacteria




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. Enhanced monitoring of post contact tank and final water for bacteriological parameters.
    Date: Ongoing for the duration of this Notice
  2. Maintain compliance with established company procedures for the operation of the treatment works.
    Date: Ongoing for the duration of this Notice
  3. Maintain and continue operating all existing treatment processes at Strensham works within documented operational water quality limits and set points at all times.
    Date: Ongoing for the duration of this Notice
  4. Comply with the requirements of regulation 35(6) and the Water Industry (Suppliers’ Information) Direction 2021, to notify the Inspectorate, UK Health Security Agency and local authorities in response to events where there is a potential risk to public health from water supplied from Strensham Works
    Date: Ongoing for the duration of this Notice
  5. Continue investigatory work to find root cause of failures
    Date: Ongoing for the duration of this notice OR until a conclusive root cause is found

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

  1. Complete remedial works to Pump House 1 of the High Lift Pump Sumps
    Date: 31 December 2022
  2. Review and design the most appropriate solution to resolve the entrainment of air from the outlet of compartment 2 of the contact tank into the ‘1400 Main’.
    Date: 31 January 2023
  3. Confirm completion of the agreed solution for resolution of the air entrainment
    Date: 31 January 2024
  4. Complete works to replace the ‘1400 Main’
    • Confirm the appropriateness of the proposed solution
      Date: 31 December 2022
    • Confirm completion of design and expected start date for construction
      Date: 30 June 2024
    • Confirm completion of the required works
      Date: 31 March 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 sections (a) and (b).
    Date: Complete
  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 Strencham works, 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. Review the risk assessment for Strensham WTW as required by regulation 27(3) and subsequently submit a revised regulation 28 report accompanied by a signed board level declaration.
    Date: Ongoing for the duration of the notice
  3. Provide a report on completion of Pump House 1 (b)8, and appropriateness of solution (b)11
    Date: 31 January 2023
  4. Provide a report on the solution for air entrainment (b)9, along with any findings from the root cause analysis COMET.
    Date: 28 February 2023
  5. Provide a report confirming the completion of the solution for air entrainment (b)10.
    Date: 28 February 2024
  6. Confirm timescales for solution delivery (b)11
    Date: 31 July 2024
  7. Confirm completion of the required works.
    Date: 30 April 2027
  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: 30 April 2028

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).


Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
17 October 2022
Reference: SVT-2019-00005

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