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Wessex Water Services Limited – Discolouration

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

Reference: WSX-2021-00002

Version Number: 2

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Wessex Water Services Limited, with registered number 02366648 (hereinafter called ‘the Company’).

Assets Affected:

Asset Name

Reference

Maundown North

Z44000002

Maundown East

Z44000014

Odcombe

Z44000124

Table 1: List of assets affected and associated reference numbers

Details of this Notice:

  1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a set of regulation 28(1) report of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company received during October 2024, which state that there is or has been a significant risk of supplying water from the water quality zones listed above (and associated assets as applicable) that 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 (discolouration)

Aluminium

Multiple, for example RSKASMT-0000003257 H057 Z44000002

Consumer Acceptability (discolouration)

Iron

Multiple, for example RSKASMT-0000003257 H057 Z44000002

Consumer Acceptability (discolouration)

Manganese

Multiple, for example RSKASMT-0000003257 H057 Z44000002

Consumer Acceptability (discolouration)

Turbidity

Multiple, for example RSKASMT-0000003257 H057 Z44000002

Consumer Acceptability (discolouration)

Discolouration

Multiple, for example RSKASMT-0000003257 H057 Z44000002

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.
  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.

Requirements:

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

  1. Undertake regulatory and enhanced monitoring as defined within section (c)i from treatment works, reservoirs and any water supply zones identified as being at risk of discolouration, including the zones listed within this Notice.
    Date: Ongoing for the duration of this Notice
  2. Investigate any failure of a discolouration parameter (Aluminium, Iron, Manganese or Turbidity) and determine root cause.
    Date: Ongoing for the duration of this Notice
  3. Record and monitor customer contacts in appropriate detail and, along with water quality data, keep under review to inform the forward programme of work.
    Date: Ongoing for the duration of this Notice
  4. Deliver a programme of proactive and reactive flushing work on the distribution network, to manage discolouration risks.
    Date: Ongoing for the duration of this Notice
  5. Optimisation of existing treatment processes with particular regard to the removal of Aluminium, Iron and Manganese.
    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. Develop a discolouration strategy to reduce the risk of discoloured water in water supply zones, which is benchmarked against industry good practice. To include:
    • Treatment works
    • Service Reservoirs
    • Trunk mains
    • Zonal network

Date: Complete

  1. Develop a dynamic risk assessment methodology for water supply zones, utilising all relevant sources of data and with input from relevant stakeholders, to prioritise zones for further investigation and remedial work to reduce the risk of consumer contacts regarding discoloured water. To include:
    • Treatment works
    • Service Reservoirs
    • Trunk mains
    • Zonal network

Date: Complete

  1. Develop a discolouration root cause analysis methodology to understand the reasons for discolouration, utilising all relevant sources of data, with input from relevant stakeholders.
    Date: Complete
  2. Review discolouration data from all sources, complete risk assessments for all zones and prioritise high and medium risk zones for root cause analysis.
    Date: 31 March 2022 and then annually for the duration of the notice
  3. Undertake a root cause analysis in the zones identified at the top of this Notice and in b(4), to understand discolouration within the Company’s zones using all available sources of data. The outcome of this analysis should form the basis of the company’s evidence base for the AMP8 business plan submission.
    Date: 30 September 2022 and then ongoing for the duration of the notice.
  4. Using the outputs from the root cause analysis in b(5), develop a bespoke strategy with timescales for the zones at the top of this notice and all high-risk zones identified in b(4), to reduce the risks of discolouration to consumers. This should be specific to each zone and include as required:
    • Treatment works optimisation
    • Service Reservoir cleaning and risk assessment
    • Trunk mains conditioning/ remediation
    • Distribution modelling, flushing, monitoring, network configuration review and optimisation, mains rehabilitation, abandonment/ replacement, standpipe management

Date: 31 December 2022 and then ongoing for the duration of the notice.

  1. Implement bespoke solutions as identified in b(vi), prioritising zones to an agreed programme with highest risks for discolouration, consumer contacts and consumer acceptability to achieve the following;
    • Phase 1 – By 2025 a reduction in consumer contacts for discolouration to below the target of 0.6 per 1000 population regionally and below the individual targets identified in audit strategy for zones listed at the top of the notice.
      Date: 31 December 2024
    • Phase 2 – Develop strategy to deliver required work for improvements in discolouration contacts in AMP8, taking into account performance improvements attained in AMP7.
      Date: Complete
    • Agree an AMP8 target for reduction on discolouration contacts regionally (to be a maximum of 0.4 contacts per 1000 population) and for individual zones. The regional target should be in line with the rest of the drinking water industry anticipated average.
      Date: Complete
    • Phase 3 – Implement AMP8 strategy developed above to completion and achieve the targets;
      • A maximum discolouration contact rate for any individual zone of 0.94 contacts per 1000 population.
      • An average company-wide performance for discolouration contact rates of 0.3 contacts per 1000 population.

Date: 31 March 2030

(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: Complete
  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 water quality zones listed in this notice, 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 a copy of the audit strategy.
    Date: Complete
  3. Submit a copy of the discolouration strategy developed in b(1).
    Date: Complete
  4. Provide a report detailing the dynamic risk assessment methodology developed in b(2).
    Date: Complete
  5. Provide a report detailing the root cause analysis methodology developed in b(3).
    Date: Complete
  6. Provide a report detailing which zones will be prioritised for root cause analysis in b(4).
    Date: Annually by 30 April
  7. Provide a report into the outputs of the root cause analysis and the bespoke solutions identified in b(5).
    Date: Complete
  8. Provide an interim report of the work completed for the notice to date and confirm the company has met the phase 1 target as defined within b(7).
    Date: Complete
  9. Provide a copy of the discolouration strategy for AMP8 as defined in b(7).
    Date: Complete
  10. Provide a report to confirm the agreed target for reduction in discoloured water contacts and the strategy for AMP8, as defined within b(7).
    Date: Complete
  11. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  12. 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
  13. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 April 2031

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).

Signed

Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
16 December 2024
Reference: WSX-2021-00002 v2

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