Notice of Regulation: Thames Water – Risk from Flooding
THE WATER SUPPLY (WATER QUALITY) REGULATIONS 2016 (AS AMENDED)
NOTICE UNDER REGULATION 28(4)
THAMES WATER UTILTIES LTD: Risk from Flooding
Site Names and references: see Annex 1
DWI Reference: TMS3892
THE SECRETARY OF STATE:
- has on 21 October 2017 received a report (the “Report”) from Thames Water Utilities Ltd (the “Company”) which states that there is or has been a significant risk of supplying water from the catchments and sites listed in Annex 1 that could constitute a potential danger to human health or could be unwholesome.
- GIVES NOTICE to the Company under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended) (“the Regulations”) that it must satisfy the following requirements:
For risks associated with:
- Site contamination [risk from flooding]
Requirements
(a) to maintain the following measures for the period specified:
To ensure that wholesome water is supplied to consumers at all times, in accordance with the requirements of regulation 4, maintain existing operational measures which must include the following at all sites (catchments and their corresponding water treatment works as applicable)covered by this Notice:
Date: Ongoing for the duration of this Notice
- Operation of all processes within defined operating ranges with appropriate triggers, responses and contingency procedures with associated review programmes.
- Maintain continuous turbidity monitoring of water prior to disinfection with appropriate alarms and failsafe shutdowns where applicable. Respond to alarms from these monitors as per Company procedures.
- Ensure all water treatment works’ control and shutdown systems are operational and that monitors are calibrated at predefined frequencies.
- Continuous monitoring of raw and treated water with control systems, alarmed operating limits and automatic shutdown as appropriate.
- Ensure that turbidity monitoring equipment is maintained in-line with manufacturers’ instructions.
- Continuously review all critical control points and mitigation measures for the duration of this Notice with a view to updating the 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.
- Water quality response procedures for: investigation of contraventions including process optimisation and reporting; customer complaints procedures; event response procedures for event actions and notification criteria.
- Up-to-date Site Operating Manual (SOM), defining normal operating ranges, triggers, response and contingency procedures, with controlled update and review programmes.
- The Company’s internal waiver process is followed where deviation from the Asset Standard is required. This must not affect compliance with the Regulations.
- Up-to-date and subject to continuous review, site specific disinfection policies, which identify clearly and unequivocally how disinfection is achieved at the water treatment works.
- Maintain contingency plans to protect human health in the event of a risk to human health 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.
- In accordance with the requirements of regulation 27(3), continuously review and revise as necessary the regulation 27 risk assessments for the sites and submit revised regulation 28 reports to the Inspectorate as necessary, in accordance with the published procedure.
(b) to review, revise or make operational the following measures, by the date specified below:
Measures for all sites listed in Annex 1
- a) Review all catchments and water treatment works where screening indicates a potential risk from groundwater flooding.
Date: 31 March 2019 - b) Identify any measures required to address the findings of the review completed under measure (b)1.a) above.
Date: 30 June 2019 - c) Implement any required measures identified under (b)1.b) above.
Date: 31 December 2023
- a) Review all catchments and water treatment works where screening indicates a potential risk from groundwater flooding.
- a) Review all catchments and water treatment works where screening indicates a potential risk from fluvial or pluvial flooding.
Date: 31 March 2019 - b) Identify any measures required to address the findings of the review completed under measure (b)2.a) above.
Date: 30 June 2019 - c) Implement any required measures identified under (b)2.b) above.
Date: 31 December 2023
- a) Review all catchments and water treatment works where screening indicates a potential risk from fluvial or pluvial flooding.
Measures for Eton abstraction features and Datchet water treatment works
- a) Complete a flood risk assessment for Eton abstraction features (including Eton pumping station).
Date: Complete - b) Identify any measures required to address the findings of the flood risk assessment completed under measure (b)3.a) above.
Date: Complete - c) Implement any required measures identified under (b)3.b) above.
Date: 31 March 2020
- a) Complete a flood risk assessment for Eton abstraction features (including Eton pumping station).
- a) Complete a flood risk assessment of the Datchet boreholes and Datchet water treatment works.
Date: 31 March 2019 - b) Identify any measures required to address the findings of the flood risk assessment completed under measure (b)4.a) above.
Date: 31 March 2019 - c) Implement any required measures identified under (b)4.b) above.
Date: 31 March 2020
- a) Complete a flood risk assessment of the Datchet boreholes and Datchet water treatment works.
(c) to audit whether the measures have been effective by the following means:
- Define a strategy for auditing the effectiveness of the above measures.
Date: 31 July 2019 - Implement the audit strategy outlined above.
Date: Until revocation of this Notice.
(d) not to supply water for regulation 4(1) purposes from sites listed in Annex 1, unless the conditions specified below are satisfied:
- 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:
- Provide a progress report annually by 31 January each year after the final notice is served and against the following milestones:
- a) Report outlining the findings of the review completed under (b)1.a) and (b)2.a) and the measures to be taken to address any deficiencies identified (as required under measure (b)1.b) and (b)2.b)) and their proposed timescales for delivery.
Date: 31 July 2019 - b) Confirmation of the completion of any measures required under measure (b)1.c) and (b)2.c).
Date: 30 January 2024 - c) Report outlining the findings of the flood risk assessment completed under (b)4.a) and the measures to be taken to address any deficiencies identified (as required under measure (b)4.b)) and their proposed timescales for delivery.
Date: 30 April 2019 - d) Confirmation of the completion of any measures required under measure (b)3(c) and (b)4.c)
Date: 30 April 2020
- a) Report outlining the findings of the review completed under (b)1.a) and (b)2.a) and the measures to be taken to address any deficiencies identified (as required under measure (b)1.b) and (b)2.b)) and their proposed timescales for delivery.
- Review the risk assessment for the sites covered by this Notice and their associated supply systems as required by regulation 27(4) and subsequently submit revised regulation 28 reports accompanied by signed board level declarations.
Date: From time to time and 2 months after the completion of all measures in section (b) - Submit a satisfactory completion report.
Date: 01 March 2025
Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Act.
Signed by authority of the Secretary of State,
Laura Moss
Deputy Chief Inspector
08 July 2020
DWI reference: TMS3892
Version 2
Annex 1- Sites
Part I – Catchments and their corresponding water treatment works
Catchments identified by screening as being potentially at risk from flooding.
Catchment name | Catchment Ref. | Connected Water Treatment Works Name | Connected Water Treatment Works Ref. | Flooding | Risk | Type |
|---|---|---|---|---|---|---|
Pluvial | Fluvial | Ground water | ||||
Addington Catchment | C01U.101 | Addington | T01U.101 | Ground water | ||
Ashton Keynes Catchment | C07U.722 | Ashton Keynes | T07U.722 | Ground water | ||
Bishops Green Catchment | C06U.615 | Bishops Green | T06U.615 | Ground water | ||
Bradfield Valley Catchment | C06U.620 | Bradfield | T06U.620 | Ground water | ||
Bradfield Windmill Catchment | C06U.670 | Bradfield | T06U.620 | Ground water | ||
Brantwood Road Catchment | C01U.170 | Brantwood | T01U.170 | Ground water | ||
Cleeve & Gatehampton (Gatehampton) Catchment | C06U.640 | Cleeve | T06U.639 | Ground water | ||
Dapdune Catchment | C04U.406 | Ladymead (Dapdune) | T04U.405 | Ground water | ||
Darenth Catchment | C01U.110 | Darenth | T01U.110 | Pluvial | Fluvial | Ground water |
Dartford Catchment | C01U.114 | Dartford | T01U.114 | Pluvial | Fluvial | |
Datchet & Eton (Datchet) Catchment | C03U.310 | Datchet/ Eton | T03U.310 | Pluvial | Fluvial | Ground water |
Datchet & Eton (Eton) Catchment | C03U.338 | Datchet/ Eton | T03U.310 | Pluvial | Fluvial | |
Deptford Catchment | C01U.115 | Deptford | T01U.115 | Pluvial | Fluvial | Ground water |
Dorney & Taplow (Dorney) Catchment | C03U.318 | Dorney/ Taplow | T03U.318 | Pluvial | Fluvial | Ground water |
Dorney & Taplow (Taplow) Catchment | C03U.319 | Dorney/ Taplow | T03U.318 | Ground Water | ||
Enborne Grange Catchment | C06U.632 | Enborne Grange | T06U.632 | Pluvial | Fluvial | Ground water |
Epsom (Nonsuch, Main & Rail) Catchment | C01U.119 | Epsom | T01U.119 | Ground Water | ||
Eynsford Catchment | C01U.124 | Eynsford | T01U.124 | Pluvial | Fluvial | |
Greys Road Henley Catchment | C06U.626 | Greys Road | T06U.626 | Pluvial | Fluvial | |
Hambleden (Medmenham) Catchment | C03U.333 | Hambleden | T03U.333 | Ground Water | ||
Hampden Bottom Catchment | C05U.504 | Hampden Bottom | T05U.504 | Pluvial | Fluvial | |
Hawridge Catchment | C05U.505 | Hawridge | T05U.505 | Ground Water | ||
Hoddesdon (Essex Road) Catchment | C02U.366 | Chingford South | T02S.004 | Ground Water | ||
Horton Kirby Catchment | C01U.129 | Horton Kirby | T01U.129 | Pluvial | Fluvial | Ground water |
Kangley Bridge (Bell Green) Catchment | C01U.111 | Kangley Bridge | T01U.111 | Ground Water | ||
Ladymead Catchment | C04U.405 | Ladymead (Dapdune) | T04U.405 | Pluvial | Fluvial | Ground water |
Langley Vale Catchment | C01U.132 | Langley Vale | T01U.132 | Pluvial | Fluvial | |
Latton & Meysey Hampton (Latton) Catchment | C07U.709 | Latton (M. Hampton) | T07U.709 | Ground Water | ||
Latton & Meysey Hampton (Meysey Hampton) Catchment | C07U.710 | Latton (M. Hampton) | T07U.709 | Ground Water | ||
Lea Bridge Catchment | C02U.331 | Coppermills | T02S.001 | Pluvial | Fluvial | |
Leckhampstead Catchment | C06U.633 | Leckhampstead | T06U.633 | Pluvial | Fluvial | Ground Water |
Merton Abbey Catchment | C01U.135 | Merton Abbey | T01U.135 | Ground Water | ||
Middlefield Road Catchment | C02U.367 | Chingford South | T02S.004 | Ground Water | ||
Millmead Catchment | C04U.404 | Millmead | T04U.404 | Pluvial | Fluvial | Ground water |
Netley Mill & Albury (Brook, Albury) Catchment | C04U.401 | Netley Mill/ Albury | T04U.401 | Ground Water | ||
Netley Mill & Albury (Netley Mill) Catchment | C04U.472 | Netley Mill/ Albury | T04U.401 | Ground Water | ||
Pann Mill Catchment | C03U.325 | Pann Mill | T03U.325 | Ground Water | ||
Radnage Catchment | C03U.322 | Radnage | T03U.322 | Pluvial | Fluvial | Ground water |
Sheeplands Catchment | C06U.643 | Sheeplands | T06U.643 | Ground Water | ||
Shortlands Catchment | C01U.153 | Shortlands | T01U.153 | Pluvial | Fluvial | |
Southfleet Catchment | C01U.156 | Southfleet | T01U.156 | Pluvial | Fluvial | |
Speen Catchment | C06U.613 | Speen | T06U.613 | Ground Water | ||
Streatham Catchment | C01U.158 | Streatham | T01U.158 | Ground Water | ||
Sundridge Catchment | C01U.160 | Sundridge | T01U.160 | Pluvial | Fluvial | |
Swell (Upper) Catchment | C07U.702 | Upper Swell | T07U.702 | Pluvial | Fluvial | |
Ufton Nervet Catchment | C06U.621 | Ufton Nervet | T06U.621 | Ground Water | ||
Waddon Catchment | C01U.169 | Waddon | T01U.169 | Ground Water | ||
Waltham Abbey (Waltham Abbey & Rammey Marsh) Catchment | C02U.236 | Waltham Abbey | T02U.236 | Pluvial | Fluvial | |
Wansunt Catchment | C01U.173 | Wansunt | T01U.173 | Ground Water | ||
Wantage (Manor Road) Catchment | C06U.601 | Wantage Manor Road | T06U.601 | Ground Water | ||
Watlington Catchment | C05U.509 | Watlington | T05U.509 | Ground Water | ||
West Wickham Catchment | C01U.179 | West Wickham | T01U.179 | Ground Water | ||
Wilmington Catchment | C01U.181 | Wilmington | T01U.181 | Ground Water |
Part II – Water Treatment Works
Water treatment works identified by screening as being potentially at risk from flooding.
Catchment name | Catchment Ref. | Flooding | Risk | Type |
|---|---|---|---|---|
Pluvial | Fluvial | Groundwater | ||
Coppermills WTW | T02S.001 | Pluvial | Fluvial | |
Hornsey WTW | T02S.002 | Pluvial | Fluvial | |
Shalford WTW | T04S.002 | Pluvial | Fluvial |
END OF ANNEX 1