Southern Water Services Limited – Weirwood Multi Phase

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

Reference: SRN-2024-00016

Version Number: 1

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Southern Water Services Limited, with registered number 02366670 (hereinafter called ‘the Company’).

Assets Affected:

Asset Name	Reference
Weirwood Forest Row WSW	TS009
Weirwood Forest Row Supply System	Y040

Table 1: List of assets affected and associated reference numbers

Details of this Notice:

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 19 November 2018, which states that there is or has been a significant risk of supplying water from Weirwood Forest Row Water Supply Works (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
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
Catchment risks and failure or treatment process	Clostridium perfingens	47073
Catchment risks and failure or treatment process	E. coli	47076
Catchment risks and failure or treatment process	Enterococci	47077
Catchment risks and failure or treatment process	Total Coliforms	47075
Catchment risks and failure or treatment process	Parasites(Cryptosporidium)	47072
Insufficient water supply to downstream consumers	No Supply	47131, 47132, 47133

Table 2: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.

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:

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

Continue progressing the Sussex North schemes, in order to support the Hardham WSW supplies to customers in the Sussex North Resource Zone while the new treatment stream at Weirwood WSW is being built.
Date: Ongoing for the duration of this Notice
Ongoing monitoring of regulatory and operational sample results and online data, once available.
Date: Ongoing for the duration of this Notice
Enhanced sampling for colony counts (at 22^oC), TOC, coliforms and E. coli in the treated water supplied.
Date: Ongoing for the duration of this Notice
To monitor treated water supplied using flow cytometry.
Date: Ongoing for the duration of this Notice
Carry out Remote Operated Vehicle (ROV) surveys at frequency set out in audit strategy.
Date: Ongoing for the duration of this Notice
Enhance the frequency of interstage sampling to enable more granular monitoring and optimisation of the treatment process.
Date: Ongoing for the duration of this Notice
Enhanced monitoring (as a minimum 3 times per week) for Cryptosporidium in the raw and treated water.
Date: Ongoing for the duration of this Notice
Establish and maintain in place until improvement works are completed such enhanced operational measures as necessary to ensure that consumers are protected, and water supplied from the site is adequately treated and wholesome.
Date: Ongoing for the duration of this Notice
Liaise with UK Health Security Agency and local authorities in the event of any breach of a health-based standard.
Date: Ongoing for the duration of this Notice
Maintain and operate works treatment in accordance with WSW site specific maintenance schedule and Routine Site Task Lists.
Date: Ongoing for the duration of this Notice
Produce daily working weekday trends review in accordance with WSM 202.06 to flag all risks and potential opportunities for process optimisation.
Date: Ongoing for the duration of this Notice
Validate dosing flow monitoring at a frequency commensurate with treatment changes and as a minimum in line with manufacturer’s instructions.
Date: Ongoing for the duration of this Notice
Continuous on-line monitoring of chlorine concentration and turbidity with appropriate alarm levels and automatic shutdown pre and post disinfection.
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:

Confirm the programme of works for Phase 1, 2 and 3 of the new Weirwood WSW, including the programme for completion of:
a) Construction.
b) Commissioning.
c) Asset Integration.
d) Training of operational staff.
Date: 31 December 2024
Confirm the completion of the following Phase 1 (5.4Mld) milestones at Weirwood WSW.
a) Construction of Phase 1.
b) Commissioning of Phase 1.
c) Asset Integration of Phase 1.
d) Training of operational staff on the new operation and maintenance of the new water treatment processes constructed and commissioned in Phase 1.
Date: 31 October 2026
Confirm the completion of the following Phase 2 (13Mld) milestones at Weirwood WSW.
a) Construction of Phase 2.
b) Commissioning of Phase 2.
c) Asset Integration of Phase 2.
d) Training of operational staff on the new operation and maintenance of the new water treatment processes constructed and commissioned in Phase 2.
Date: 31 December 2028
Confirm the completion of the following Phase 3 (21Mld) milestones at Weirwood WSW.
a) Construction of Phase 3.
b) Commissioning of Phase 3.
c) Asset Integration of Phase 3.
d) Training of operational staff on the new operation and maintenance of the new water treatment processes constructed and commissioned in Phase 3.
Date: 31 December 2030

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

Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
Date: 31 January 2025
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 Weirwood Forest WSW, or not to so supply unless the specified conditions below are satisfied:

To keep sampling and any inspections under constant review and cease supply if any Water Quality deterioration observed. In such event the inspectorate, the local council and UKHSA is to be informed immediately.
Date: For 6 months post Phase 1 returning to supply

(e) To provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risks:

Provide a progress report annually.
Date: by 31 January each year.
Provide a report confirming the programme of works for Phase 1, 2, 3 of the new Weirwood WSW, including the programme for completion of:
a) Construction.
b) Commissioning.
c) Asset Integration.
d) Training of operational staff.
Date: 31 January 2025
Submit application as per Regulation 15 (1) (a) before bringing supply back to work.
Date: At least 1 month prior to returning to supply
Provide update reports on progress against the confirmed Phase 1 programme of works at 6 monthly intervals.
a) Weirwood update report 1
Date: 30 April 2025

b) Weirwood update report 2
Date: 31 October 2025

c) Weirwood update report 3
Date: 30 April 2026
Provide a report confirming the completion of the following Phase 1 milestones at Weirwood WSW.
a) Construction of Phase 1.
b) Commissioning of Phase 1.
c) Asset Integration of Phase 1.
d) Training of operational staff on the new operation and maintenance of the new water treatment processes constructed and commissioned in Phase 1
e) Supply of water from Weirwood WSW into the downstream supply network
f) Provide a confirmation the site was run into supply
Date: 30 November 2026
Provide a report confirming the completion of the following Phase 2 milestones at Weirwood WSW.
a) Construction of Phase 2.
b) Commissioning of Phase 2.
c) Asset Integration of Phase 2.
d) Training of operational staff on the new operation and maintenance of the new water treatment processes constructed and commissioned in Phase 2.
Date: 31 January 2029
Provide a report confirming the completion of the following Phase 3 milestones at Weirwood WSW.
a) Construction of Phase 3.
b) Commissioning of Phase 3.
c) Asset Integration of Phase 3.
d) Training of operational staff on the new operation and maintenance of the new water treatment processes constructed and commissioned in Phase 3.
Date: 31 January 2031
Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
Date: 28 February 2025
Submit any revisions of the audit strategy produced under measure (c)2.
Date: Within 1 month of a revision
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
Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
Date: 31 January 2032

Further Details of this Notice:

Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
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.
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).
Contravention of a regulation 28(4)(d) requirement is an offence under regulation 33(1). If guilty of such an offence, the Company is liable on summary conviction, or on conviction on indictment, to a fine. Under regulation 33(2) it is a defence for the Company to show that it took all reasonable steps and exercised all due diligence to avoid the commission of the offence.

Signed

Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
16 December 2024
Reference: SRN-2024-00016 V1

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