South West Water Limited – AMP8 Multiple Sites Powdered Activated Carbon (PAC)

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

Reference: SWB-2023-00012

Version Number: 1

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): South West Water Limited, with registered number 02366665 (hereinafter called ‘the Company’).

Assets Affected:

• De Lank WTW – T2308F De Lank Supply System – Y2308
• Bastreet WTW – T5302F Bastreet Supply System – Y5302
• St Cleer WTW – T5330F St Cleer Supply System – Y5330
• Prewley WTW – T3832F Prewley Supply System – Y3832
• Avon WTW – T6802F Avon Supply System – Y6802
• Dousland WTW – T5310F Dousland Supply System – Y5310
• Venford WTW – T6840F Venford Supply System – Y6840

Details of this Notice:

1. The Drinking Water Inspectorate (‘the Inspectorate’) has received regulation 28(1) reports of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated between 3 February 2023 and 18 January 2024, which states that there is or has been a significant risk of supplying water from De Lank, Bastreet, St Cleer, Prewley, Avon, Dousland and Venford Water Treatment 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
Consumer acceptability (taste and odour)	Geosmin (F050)	Multiple hazard lines including:   De Lank WTW 1481
Consumer acceptability (taste and odour)	2-Methylisoborneol (F051)	Multiple hazard lines including:   De Lank WTW: 1480
Consumer acceptability (taste and odour)	Taste (A004)	Multiple hazard lines including:   De Lank WTW: 1475
Consumer acceptability (taste and odour)	Odour (A003)	Multiple hazard lines including:   De Lank WTW: 1476

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.

3. 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:

1. Maintain monitoring in line with frequencies defined in the audit strategy.
   Date: Ongoing for the duration of this Notice
2. Maintain statutory sampling as defined in the Regulations.
   Date: Ongoing for the duration of this Notice
3. Optimisation of the existing mitigation measures within the operational limits of the processes which have an impact on Geosmin and/or 2-MIB concentrations in the final water.
   Date: Ongoing for the duration of this Notice
4. Respond to and investigate any PCV failure or consumer contact relating to earthy/musty taste or odours in appropriate detail and in line with company procedures.
   Date: Ongoing for the duration of this Notice
5. Inform an on-going raw water risk assessment by enhanced monitoring.
   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. Plan and develop the outline design of the mobile PAC dosing system integration at each WTW.
   Date: 31 October 2025
2. Complete the installation of the mobile PAC dosing system integration infrastructure at each WTW.
   Date: 30 April 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 August 2024
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 De Lank, Bastreet, St Cleer, Prewley, Avon, Dousland and Venford Water Treatment Works, 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 January each year.
2. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
   Date: 30 September 2024
3. Confirm the outline design of the mobile PAC dosing system integration at each WTW.
   Date: 30 November 2025
4. Confirm completion of the installation of the mobile PAC dosing system integration infrastructure at each WTW.
   Date: 31 May 2027
5. Submit any revisions of the audit strategy produced under measure (c)2.
   Date: Within 1 month of a revision
6. 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
7. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
   Date: 31 May 2028

Further Details of this Notice:

4. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
5. 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.
6. 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
8 April 2024
Reference: SWB-2023-00012