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 V2

THE SECRETARY OF STATE:

1. 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.
2. 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

1. Operation of all processes within defined operating ranges with appropriate triggers, responses and contingency procedures with associated review programmes.
2. 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.
3. Ensure all water treatment works’ control and shutdown systems are operational and that monitors are calibrated at predefined frequencies.
4. Continuous monitoring of raw and treated water with control systems, alarmed operating limits and automatic shutdown as appropriate.
5. Ensure that turbidity monitoring equipment is maintained in-line with manufacturers’ instructions.
6. 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.
7. 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.
8. Up-to-date Site Operating Manual (SOM), defining normal operating ranges, triggers, response and contingency procedures, with controlled update and review programmes.
9. The Company’s internal waiver process is followed where deviation from the Asset Standard is required. This must not affect compliance with the Regulations.
10. 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.
11. 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.
12. 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

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

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

1. Define a strategy for auditing the effectiveness of the above measures.
   Date: 31 July 2019
2. 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:

1. 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 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
2. 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)
3. Submit a satisfactory completion report.
   Date: 01 March 2025

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

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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 T06U.640 T06U.641 T06U.642			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 Epsom (New Stream)	T01U.119 T01U.120			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 Coppermills Hornsey	T02S.004 T02S.001 T02S.002			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 Coppermills Hornsey	T02S.004 T02S.001 T02S.002			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 T06U.638			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 T04S.003 T04S.004 T04S.005	Pluvial	Fluvial

END OF ANNEX 1