Southern Water Services Limited – Hardham / Laws Aquifer Combined and Cocking Hill WSR Iron

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

Reference: SRN-2020-00006

Version Number: 2

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:

  • RS006 – Cocking High WSR
  • ZS533 – Hardham / Laws Aquifer Combined

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 13 October 2020, which states that there is or has been a significant risk of supplying water from Cocking High Water Service Reservoir and Hardham / Laws Aquifer Combined Water Supply Zone (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

Reservoir integrity and mains network arrangements


45812 and 45192

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. Enhanced iron level monitoring at Cocking High WSR.
    Date: Ongoing for the duration of this Notice
  2. Take and analyse sufficient additional samples for iron throughout the year from Hardham / Laws Aquifer Combined WSZ, to supplement current regulatory monitoring.
    Date: Ongoing for the duration of this Notice
  3. Respond as required to any PCV failures in line with company procedures. Carry out an investigation to determine the root cause of any failures.
    Date: Ongoing for the duration of this Notice
  4. Maintain liaison with Public Health England and Local Authorities where there is a breach of the prescribed concentrations.
    Date: Ongoing for the duration of this Notice
  5. Follow the site operating plan at Cocking High WSR until a solution to mitigate the Iron risk has been applied successfully.
    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. All Galvanised Iron (GI) pipe work within Cocking Water Booster Station to be replaced.
    Date: Complete
  2. Carry out a flush of the main from the Booster Station to Cocking High WSR.
    Date: Complete
  3. Investigate issue and confirm notional solution to mitigate risk of high iron levels within the network. Confirm the date the detailed design with delivery dates will be completed.
    Date: Complete
  4. Develop a detailed design to mitigate issues and provide delivery dates.
    Date: Complete
  5. Build and commission long term solution.
    Date: 31 March 2023

(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: 30 September 2022
  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 Cocking Hill WSR, 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. Confirm that actions (b)1 and 2 have been completed.
    Date: Complete
  3. Confirm scope of works following the investigations for a long-term solution, to also include completion dates for measures (b)4.
    Date: Complete
  4. Provide detailed design to mitigate the issue, including delivery dates.
    Date: Complete
  5. Provide completion report for build and commission long term solution.
    Date: 30 April 2023
  6. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 31 October 2022
  7. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  8. 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
  9. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 April 2024

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
26 August 2022
Reference: SRN-2020-00006 V2

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