South West Water Limited – AMP8 Woodgreen WTW

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

Reference: SWB-2023-00008

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:

  • Woodgreen WTW T9400F
  • Woodgreen Supply System Y9400

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 31 March 2023, which states that there is or has been a significant risk of supplying water from Woodgreen WTW (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 to disinfection

Turbidity (A002A)


Consumer acceptability (discolouration)

Manganese (A023)


Consumer acceptability (discolouration)

Discolouration (H057)


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.


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

  1. Continue to operate Woodgreen WTW treatment process to ensure compliance with regulation 26 and regulation 4 of the Regulations.
    Date: Ongoing for the duration of this Notice.
  2. Maintain monitoring in line with frequencies defined in the audit strategy.
    Date: Ongoing for the duration of this Notice.
  3. Maintain statutory sampling as defined in the Regulations which includes manganese sampling.
    Date: Ongoing for the duration of this Notice.
  4. Maintain the risk-based DOMS flushing program.
    Date: Ongoing for the duration of this Notice.
  5. Respond to any exceedance of PCV or consumer contacts relating to discolouration parameters in line with company procedures.
    Date: Ongoing for the duration of this Notice.
  6. Inform 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 long-term solution inclusive of a programme of works to mitigate turbidity and reduce the manganese concentration in the treated water.
    Date: 31 March 2026
  2. Complete the detailed design of the chosen solution and commence construction.
    Date: 31 March 2027
  3. Complete the construction, installation and commissioning of the long-term solution.
    Date: 31 March 2028

(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 June 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 Woodgreen WTW , 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 August 2024
  3. Provide a report confirming the chosen solution and design for the Woodgreen WTW replacement treatment process and provide the programme of works.
    Date: 30 April 2026
  4. Provide the detailed design of chosen solution.
    Date: 30 April 2027
  5. Confirm completion of the installation and commissioning of the chosen solution. Commissioning must include the following to account for the changes made:
  • An appropriate maintenance regime for any installed processes;
  • Full integration of the new (or modified) processes into the site control and monitoring systems.
  • Updating of the Site-Specific Disinfection Policy and any associated site-specific procedures;
  • Updating of the Site Operating Manual and removal of all out-of-date material from circulation; and
  • Provisions of adequate training for all relevant personnel on the operation, repair and maintenance of the installed (or modified) process and the revised procedures, policies and manual.
    Date: 30 April 2028
  1. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  2. 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
  3. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 April 2029

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).


Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
13 March 2024
Reference: SWB-2023-00008

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