Current improvement programmes

Notice of Regulation: Strensham Contact Tank Improvement Scheme



Severn Trent Water: Strensham Contact Tank Improvement Scheme

T0118 Strensham works

DWI Reference: SVT-2019-00005


  1. has received a report from Severn Trent Water (the “Company”) dated 29 May 2018 (the “Report”) which states that there is or has been a significant risk of supplying water from Strensham works, that could constitute a potential danger to human health.
  2. GIVES NOTICE to the Company under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended) that it must satisfy the following requirements:

For risks associated with:

  • Escherichia coli (E.coli)
  • Coliform bacteria
  • Enterococci spp.


(a) to maintain the following measures for the period specified:

  1. Enhanced monitoring of post contact tank and final water for bacteriological parameters.
    Date: Ongoing
  2. Maintain compliance with established company procedures for the operation of the treatment works.
    Date: Ongoing
  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
  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

(b) to review, revise and/or make operational the following measures, by the date specified below:

  1. Construct a waterproof, temporary structure to protect the contact tank from exposure to the elements.
    Date: COMPLETE
  2. Complete remedial works to both compartments of the contact tank as defined by the company’s action plan
    • Complete interim remedial work to compartment 2 to allow compartment 1 to be removed from service.
      Date: COMPLETE
    • Complete permanent remedial work to compartment 1, including removal of concrete screed and remediation of roof and wall joints.
      Date: COMPLETE
    • Complete permanent remedial works to compartment 2.
      Date: 31 December 2021
  3. Investigate the operation of the “1400 Main” to define the scope of any required remedial works and confirm timescale for delivery.
    Date: COMPLETE
  4. Review and complete required remedial works and hydraulic improvements to the three compartments of the balance tank.
    Date: 31 December 2021
  5. Complete a detailed end to end review of Strensham Works, involving a full review of hazards, WQ data, review of processes, points of failure and critical control points and existing controls, and identify improvement measures.
    Date: 31 March 2022
  6. Confirm any permanent improvement measures required, and target completion dates, identified as a result of the measures specified in (b)5 above.
    Date: 30 April 2022
  7. Complete and commission improvement measures identified and required in (b)6.
    Date: TBC

(c) to audit whether the measures have been effective by the following means:

  1. Enhanced monitoring for bacteriological parameters post contact tank and final water.
    Date: Ongoing for the duration of the notice
  2. Assurance of remedial works as defined by the company’s Chief Engineer department.
    Date: Ongoing for the duration of the notice
  3. Optimising existing treatment processes.
    Date: Ongoing for the duration of the notice
  4. Weekly process control health checks.
    Date: Ongoing for the duration of the notice
  5. Continuous online monitor data thorough plant to provide verification of process performance at key points within the process and assurance that the plant is operating within the agreed limits of the plant.
    Date: Ongoing for the duration of the notice

(d) n/a

(e) to provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risk of supplying water that would constitute a potential danger to human health:

  1. Provide a progress report annually by 31 January and against the following milestones:
    • Action plan report following completion of investigations into ‘1400’ main.
      Date: Complete
    • Completion of remedial works to contact tank compartment 1
      Date: Complete
    • Completion of remedial works to balance tank.
      Date: Complete
    • Completion of all remedial works to the contact tank.
      Date: 31 January 2022
    • To confirm completion of step (b)5 and provide end to end HazRev report of works.
      Date: 31 May 2022
    • Confirm required program of work in (b)6.Date: 31 May 2021
  2. Confirm completion of all remedial work in (b)7.
    Date: TBC
  3. 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
  4. Submit a satisfactory completion report.
    Date: TBC And 12 months after completion of (b)7

Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991.

Signed by authority of the Secretary of State
Nicholas Adjei
Deputy Chief Inspector
22 December 2021
DWI Reference: SVT-2019-00005
Version 2