Southern Water Services Limited – Discolouration; All Water Supply Zones

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

Reference: SRN-2024-00001

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:

1. All Southern Water Supply Zones

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 2017, which states that there is or has been a significant risk of supplying water from all water supply zones (WSZ) (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 (discolouration)	Aluminium	For Example: 28202
Consumer acceptability (discolouration)	Manganese (Total)	For Example: 28205
Consumer acceptability (discolouration)	Iron (Total)	For Example: 28204
Consumer acceptability (discolouration)	Turbidity	For Example: 69577

Table 1: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard ID 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. All planned work will be carried out under Safe Control of Operations (SCO) with an assessment made of the risk for discolouration before work is carried out, where the risk is high as defined in the audit strategy, customers should be forewarned.
   Date: Ongoing for the duration of this Notice
2. The network will be operated to the principles of “CALM networks” where possible.
   Date: Ongoing for the duration of this Notice
3. Any reactive emergency work carried out on the network will be carried out in accordance with the procedures detailed in the Water Distribution Manual.
   Date: Ongoing for the duration of this Notice
4. Continue to proactively engage with the Fire Services and other third-party hydrant users with regard to hydrant use.
   Date: Ongoing for the duration of this Notice
5. Company to identify, manage and enforce the misuse, waste and theft of water in more complex situations with external third parties.
   Date: Ongoing for the duration of this Notice
6. Undertake regulatory and enhanced monitoring as defined within audit strategy. To include treatment works, reservoirs and any water supply zones identified as being at risk of discolouration.
   Date: Ongoing for the duration of this Notice
7. Respond 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 a recurrence.
   Date: Ongoing for the duration of this Notice
8. Maintain liaison with UKHSA and Local Authorities where there is a breach of the prescribed concentrations.
   Date: Ongoing for the duration of this Notice
9. Optimisation of treatment for manganese, iron and aluminium at all water treatment works.
   Date: Ongoing for the duration of this Notice
10. 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
11. Training of staff and third-party contractors to facilitate more effective network operation and management and minimise disruption to customer supplies through the Company’s activities.
    Date: Ongoing for the duration of this Notice
12. Follow and implement industry best practice methodologies where appropriate. Benchmark the Company’s discolouration strategy against other water companies. Review at regular Discolouration Steering Group meetings.
    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. Identify District Metered Areas (DMAs) where there is a high risk of discolouration and where effective flushing cannot be carried out. Ensure that any work in these DMAs will be subject to an enhanced risk assessment.
   Date: 31 July 2024 and ongoing for the duration of the Notice.
2. Flushing to be undertaken in the DMAs listed in Appendix 1 at the given frequencies
   Date: Complete
3. Develop a Company discolouration management 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
4. Review and update procedures for investigating consumer contacts for discolouration, sample failures of parameters listed above and water quality discolouration events. (Include Cluster analysis/ hotspots)
   Date: Complete
5. Undertake a field trial (using WRc and PODDS tools and methodologies) in Rownhams 01 and Rownhams 02 WSZ to identify interventions that could be deployed to reduce the risk of discoloured water in water supply zones.
   Date: Complete
6. Develop a risk assessment methodology that will be dynamic 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
7. 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
8. Review discolouration data from all sources and complete risk assessments for all zones. Update regulation 28 report where necessary. Categorise into Low, Medium and High-risk zones.
   Date: by 31 October annually for the duration of the Notice
9. Undertake a root cause analysis for the zones identified as high and medium risk within (b)8, to understand discolouration within the zones. Identify bespoke solutions for each zone.
   Date: a) Complete for high-risk zones.
   Date: b) Complete for medium risk zones.
   Date: c) Annually by 31 December for new high and medium risk zones for the duration of the Notice
10. Using output from the trials in step (b)5, the root cause analysis in (b)9, and risk assessment in (b)6, develop a detailed plan for work packages for AMP8 programme with timescales for all high and medium risk zones to reduce the risks of discolouration to consumers. This should be specific to each zone and include as required.
    • Treatment works optimisation
    • Service reservoir risk assessment and cleaning
    • Work on Trunk mains and pumping stations
    • Water quality zones and DMAs
      Date: 30 June 2025 (for 2025/26 programme) and then annually by 30 April for the duration of the Notice.
11. Implement bespoke solutions as identified in (b)10, prioritising zones to an agreed programme with highest risks for discolouration, consumer contacts and consumer acceptability to achieve the following;
    • Phase 1 (AMP7) – By 2025 a reduction in discolouration contacts to an average of 0.48 per 1000 population for the Company’s region.
      Date: 31 January 2025
    • Phase 2 (AMP8) – Agree phase 2 target with the Inspectorate, to be a maximum of 0.4 per 1000 population for the Company’s region by 2030. Define additional zones and target contact rate for those zones to be included in Appendix 2.
      Date: Complete
    • Phase 2 (AMP8) – By 2030 a reduction in consumer contacts for discolouration to below;
      A maximum discolouration contact rate for zones ZH527 (Rownhams 01 Combined), ZH513 (Rownhams 02) and ZI501 (Alvington High Level) of 1.15 contacts per 1000 population.
      A maximum discolouration contact rate for all other individual zones of 0.94 contacts per 1000 population.
      An average company-wide performance for discolouration contact rates of 0.4 contacts per 1000 population.
      Date: 31 March 2030
    • Phase 3 (AMP9) – By 2035 a reduction in consumer contacts for all zones to a rate agreed with the Inspectorate during the PR29 business planning process.
      Date: 31 March 2035
12. Review performance of the AMP7 and AMP8 interventions with the Inspectorate and confirm approach for AMP9 that ensures the zones Alvington High Level, Rownhams 01 and Rownhams 02 do not exceed national average discolouration rates.
    Date: 30 March 2029
13. Document all optimisation that has been carried out as part of (a)9. at treatment works to minimise discolouration and identify outstanding actions with timelines.
    Date: annually by 30 June for the duration of the Notice

(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 all water supply zones , 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. Provide report to confirm District Metered Areas (DMAs) where there is a high risk of discolouration and where effective flushing cannot be carried out.
   Date: Complete
3. Provide a report to confirm completion of flushing undertaken in the DMA’s listed in Appendix 1 at the given frequencies as defined in step (b)2 and that the Company has met Phase 1 target as defined in step (b)11a).
   Date: 31 January 2026
4. Provide a Company discolouration management strategy to reduce the risk of discoloured water in water supply zones, which is benchmarked against industry good practice.
   Date: Complete
5. Provide a copy of the updated procedures for investigating consumer contacts for discolouration, sample failures of parameters listed above and water quality discolouration events. (Include Cluster analysis/ hotspots)
   Date: Complete
6. Provide a report detailing the field trial outcomes carried out under step (b)5. to identify interventions that could be deployed to reduce the risk of discoloured water in water supply zones.
   Date: Complete
7. Provide a report detailing the risk assessment methodology that will be dynamic for water supply zones, as developed under (b)6.
   Date: Complete
8. Provide a report detailing the root cause analysis methodology developed in step (b)7.
   Date: Complete
9. Provide report of reviewed discolouration data from all sources and complete risk assessments for all zones. Update regulation 28 report where necessary. Provide categorisation into Low, Medium, and High-risk zones.
   Date: annually by 30 November for the duration of the Notice
10. Provide report on root cause analysis for the zones identified as high and medium risk within (b)8, to understand discolouration within the zones. Identify bespoke solutions for each zone.
    Date: a) Complete for high-risk zones.
    Date: b) Complete for medium risk zones.
    Date: c) Annually by 31 January for new high and medium risk zones for the duration of the Notice
11. Provide a detailed plan for AMP8 programme with timescales for all high and medium risk zones to reduce the risks of discolouration to consumers.
    Date: 31 July 2025 then annually by 31 May for the duration of the Notice
12. Provide a report to confirm the agreed AMP8 target in discoloured water contacts in step (b)11b).
    Date: Complete
13. Provide a report for work completed to date and confirm the company has met Phase 1 target
    Date: 28 February 2025
14. Provide a report to confirm having met Phase 2 Target for AMP8.
    Date: 30 April 2030
15. Provide a report to confirm agreed AMP9 approach following review of AMP7 and AMP8 interventions.
    Date: 30 April 2029
16. Provide a report detailing optimisation that has been carried out as part of (a)9. at treatment works to minimise discolouration and identify outstanding actions with timelines.
    Date: 30 June 2025 then annually by 31 July for the duration of the Notice
17. Provide a report to confirm having met Phase 3 Target for AMP9.
    Date: 30 April 2035
18. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: Complete
19. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
20. 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
21. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 31 July 2035

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
15 May 2025
Reference: SRN-2024-00001 v2