Thames Water Utilities Limited – Hampton WTW Conditional Allowance Scheme

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

Reference: TMS-2024-00011

Version Number: 1

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Thames Water Utilities Limited, with registered number 02366661 (hereinafter called ‘the Company’).

Assets Affected:

  1. Works and supply systems listed in Annex A

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 17 May 2024, which states that there is or has been a significant risk of supplying water from Hampton 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:

Description of Risk

Hazard/ Hazardous Event/ Parameter

Hazard I D

Risk of contamination to water supplies.

Supply resilience

TMS-4-T01S.010-HEID093-T01S.010-H062

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:

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

  1. Continuous sampling for Cryptosporidium at a suitable sampling point, downstream of the slow sand filtration treatment stage at Hampton works. Date: Ongoing for the duration of this Notice.
  2. An appropriate operational sampling regime for Cryptosporidium, turbidity, microbiological faecal indicators, and other relevant parameters, within the raw water source(s) and within the water treatment works at other sampling points within the process and in the final treated water.
    Date: Ongoing for the duration of this Notice.
  3. Operation of all processes within defined operating ranges with appropriate triggers, responses, and contingency procedures. Date: Ongoing for the duration of this Notice.
  4. Ensure the works control and shutdown system is operational and that monitors are calibrated and maintained at their predefined frequencies.
    Date: Ongoing for the duration of this Notice.
  5. Continuously review all water quality critical control points and mitigation measures, with a view to updating this Notice with additional measures where required. Ensure that any new risk identified is assessed in accordance with the Company’s Drinking Water Safety Plan (DWSP) methodology.
    Date: Ongoing for the duration of this Notice.
  6. Continue to implement company water quality response procedures for investigation of contraventions including process optimisation and reporting; consumer complaints procedures; event response procedures for event actions; and notification criteria.
    Date: Ongoing for the duration of this Notice.
  7. Continue to implement the company’s Site Operating Manual (SOM), defining normal operating ranges, triggers, response, and contingency procedures, with controlled updates and review programmes. Implement the company’s Internal Waiver Process, where a deviation from the SOM is identified.
    Date: Ongoing for the duration of this Notice.
  8. Ensure that the Site-Specific Disinfection Policy for Hampton works remains up-to-date and implemented.
    Date: Ongoing for the duration of this Notice.
  9. Maintain contingency plans to protect human health in the event of a risk associated with drinking water quality, which should include liaison with local authorities and Public Health England to agree any actions needed to protect human health and issuing of advice to consumers, where required. Date: Ongoing for the duration of this Notice.
  10. In accordance with the requirements of Regulation 27(3), continuously review and revise as necessary the regulation 27 risk assessment reports for Hampton works and associated supply systems and submit revised regulation 28 reports to the Inspectorate as necessary, in accordance with the Regulations. Date: Ongoing for the duration of this Notice.
  11. Continue to implement the company’s operating standard for slow sand filters, including monthly rapid gravity filter media depth inspections. Date: Ongoing for the duration of this Notice.
  12. Trained and competent operational personnel to follow the Company’s procedure when returning slow sand filters back into supply. 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 the planning, design and procurement arrangements for the delivery of a bulk recycle flow (pre-contact tank) to the Grand Junction Reservoir and upgrades to the emergency pumping facilities at Hampton works.
    Date: 31 March 2027.
  2. Implement and commission the bulk recycle of flow (pre-contact tank) to the Grand Junction Reservoir and upgrade the emergency pumping facilities at Hampton 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: 31 May 2025.
  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 HAMPTON WORKS OR ASSOCIATED SUPPLY SYSTEMS, 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 July each year.
  2. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 30 June 2025.
  3. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision.
  4. 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.
  5. 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).

Signed

 

Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
24 February 2025
Reference: TMS-2024-00011

Annex A

Asset or Supply System Name

Reference

Hampton 1 TWRM

T01S.010

Hampton 2 South

T01S.011

Hampton 3 North

T01S-012

Chessington

YTMS1177

Norwood

YTMS1213

Addington

YTMS1167

New Cross & Riverside

YTMS1210

Knockholt

YTMS1206

Hampton 42

YTMS1198

Hampton Country

YTMS1199

Surbiton 30 inch

YTMS1224

Oxleas Wood

YTMS1215

Finsbury Park

YTMS1194

Putney

YTMS1216

Shootup Hill

YTMS1220

Castlewood

YTMS1174

Mill Hill

YTMS1209

Hampton 30/36

YTMS1197

Farnborough

YTMS1192

Westerham

YTMS1231

Ealing

YTMS1189

Crouch Hill

YTMS1186

Nunhead

YTMS1214

Bickley

YTMS1173

Barrow Hill

YTMS1172

Crystal Palace

YTMS1187

Marine Wharf, Deptford Inset (LNW) (TW Supply system Hampton 30/36)

YTMS3002

Deptford Inset (LNW) (TW Supply system Hampton 30/36)

YTMS3003

Merton Export (Sutton & East Surrey) (TW Supply system Surbiton 30 inch)

YTMS2011

Heart of East Greenwich Inset (LNW) (TW Supply system Hampton 30/36)

YTMS3005

New South Quarter, Croydon Inset (LNW) (TW Supply system Russell Hill)

YTMS3001

Sewardstone

YTMS1219

RAM Quarter, Wandsworth Inset (LNW) (TW Supply system Hampton 30/36)

YTMS3016

Maiden Lane

YTMS1207

Prince of Wales Gardens Inset (LNW) (TW Supply system Hampton 30/36)

YTMS3019

White City Inset (LNW) (TW Supply system Hampton Country)

YTMS3020

TWRM (IWNL) (TW Supply system Farnborough)

YTMS3022

Nine Elms Park Inset (IWNL) (TW Supply system Hampton 30/36)

YTMS3003

Table 2: A list of affected assets and supply zones with reference codes
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