Current improvement programmes

Notice of Regulation: Halling Water Supply




Halling Water Supply Zone (WSZ) Z322

DWI Reference: SEW 3598


  1. has received a report from South East Water Ltd (the “company”) dated 01 January 2015 (the “Report”) which states that there is or has been a significant risk of supplying water from Z322 Halling Water Supply Zone that could be unwholesome.
  2. GIVES NOTICE to the company under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended) that it must satisfy the following requirements:

For risks associated with:

  • Iron
  • Manganese
  • Turbidity


(a) to maintain the following measures for the period specified below until revocation of this Notice:

  1. Regulatory sampling from the supplying works and in the Z322 Halling WSZ
    Date: Ongoing
  2. Operate and maintain current treatment measures for iron, manganese and turbidity performance at Halling works (Aeration, Pressure filtration)
    Date: Ongoing
  3. Maintain current WSZ measures affecting iron performance in Z322 Halling WSZ (Aggressivity Control, Asset Maintenance, Calm Valve Operations, Flow/Pressure Control, Mains Remediation and Replacement and Operator Training)
    Date: Ongoing
  4. Responding as required to any PCV failure or customer contact in line with company procedures. Carry out an investigation to determine the root cause of the failure and identify any remedial measures required to prevent recurrence
    Date: Ongoing
  5. Record and monitor customer contacts at appropriate detail.
    Date: Ongoing
  6. Liaison with local and public health authorities as appropriate.
    Date: Ongoing
  7. Review and update as necessary the regulation 27 risk assessment and regulation 28 report for Z322 Halling WSZ on a monthly basis and advise DWI of any changes in risk.
    Date: Ongoing

(b) to review, revise and/or make operational the following measures, by the date specified below:

  1. Continue with risk based flushing programme of key DMAs in Z322 Halling WSZ, to include:
    Date: Complete
    • Medway Gate
    • Paddlesworth
    • Snodland
    • West Malling
  2. Continue with enhanced zonal monitoring programme in Z322 Halling WSZ gaining further insight into locality of elevated iron/discolouration levels
    Date: Ongoing
  3. Complete cleaning of all service reservoirs feeding Z322 Halling WSZ at the defined frequency.
    Date: Ongoing
  4. Complete full review of flushing programme and the discolouration risk against the defined measures of success and identify required return frequency of flushing to ensure discolouration levels are maintained at reduced level
    Date: 31 January 2023
  5. Annual review of discolouration risk and completion of further mains cleaning in subsequent financial years should the defined measures of success not be met.
    Date: Ongoing
  6. Identify the long-term strategy for mitigating the risk of discolouration in Z322 Halling WSZ.
    Date: 31 January 2023
  7. Remediation of distribution mains through targeted mains investment in the following DMAs:
    Date: 31 March 2022
    • Freemasons Snodland
    • Hollow Lane Snodland
  8. Investigation of the investment required to reduce discolouration risk in Snodland DMA.
    Date: 31 January 2021
  9. Completion of investment identified in step (b)8.
    Date: 31 March 2022

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

  1. Define and keep under continuous review an audit strategy to monitor the effectiveness of the above measures.
    Date: Complete
    • A monitoring programme to include: continuous monitoring for turbidity at Halling works; enhanced operational monitoring for iron, manganese and turbidity at Halling works and at relevant downstream service reservoirs and from consumer taps within Z322 Halling WSZ and complete a monthly review of this data.
    • Monthly review of any flushing data.
    • Monthly review of water quality operational and compliance data, event evidence and customer contact data
  2. Implement the audit strategy defined in (c)1.
    Date: For the duration of the Notice.

(d) 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 and against the following milestones:
    • Submit an Action Plan detailing the audit strategy and how success will be measured, demonstrated and sustained, as defined in (xiii). The strategy should also detail what criteria will determine whether the flushing programme has been successful or whether longer term interventions are required to feed into the long term discolouration strategy for this zone.
      Date: Complete
    • Provide a report detailing the effectiveness of the mains flushing in the Z322 Halling water supply zone
      Date: Complete
    • Submit a report detailing the long term strategy for mitigating the risk of discolouration in the Z322 Halling WSZ.
      Date: 31 January 2023
    • Confirmation of solution as identified in (b)8.
      Date: 28 February 2021
    • Completion of investment identified in steps (b)7 and (b)9.
      Date: 30 April 2022
  2. Review the risk assessment for Z322 Halling Water Supply Zone as required by regulation 27(3) and subsequently submit a revised regulation 28 report accompanied by a signed board level declaration.
    Date: From time to time and by 21 March 2023
  3. Submit a satisfactory completion report.
    Date: 30 April 2023

Failure by the company to comply with this Notice may result in enforcement proceedings under section 18 of the Water Industry Act 1991.

Signed by authority of the Secretary of State
Milo Purcell
Deputy Chief Inspector
11 August 2020
DWI Reference: SEW 3598
Version 2