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South East Water Limited – Discolouration Risk

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

Reference: SEW-2023-00001

Version Number: 2

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): South East Water Limited, with registered number 02679874 (hereinafter called ‘the Company’).

Assets Affected:

  • Whole Company

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 21 October 2022, which states that there is or has been a significant risk of supplying water from the Company’s water supply zones (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

Consumer acceptability and discolouration risk

Iron

Manganese

Aluminium

Turbidity

Discolouration

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.

Requirements:

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

  1. Undertake risk-based enhanced (in addition to routine regulatory sampling) sampling, for iron, turbidity, manganese and aluminium, from the high-risk water supply zones (identified under measure (b)8 and as updated under measure (b)14) and their associated assets, including from associated treatment works and reservoirs.
    Date: Ongoing for the duration of this Notice
  2. Maintain suitable response procedures to prescribed concentration or value exceedances (in regulatory or enhanced sampling) for iron, manganese, aluminium and turbidity. Respond to any such exceedances in accordance with the procedure and the relevant regulatory requirements.
    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. Maintain suitable response procedures to consumer contacts relating to discoloured water and respond accordingly.
    Date: Ongoing for the duration of this Notice
  5. Deliver a programme of proactive and reactive flushing work in the Company’s distribution network, based on consumer contacts and discolouration risk.
    Date: Ongoing for the duration of this Notice
  6. Optimisation of existing treatment processes, with particular regard to the removal of aluminium, manganese, iron, turbidity and other parameters relevant to discolouration.
  7. Date: Ongoing for the duration of this Notice
  8. Optimisation of any water supply zone discolouration treatment processes. 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:

Phase 1 – AMP7 targets

  1. Undertake a root cause analysis for Hockers Lane and Rushmoor Water Supply Zones to understand the risk of discolouration within these zones and the high discolouration (black/brown/orange) contact rate per 1000 population. This analysis must as a minimum include a review of the raw water risks, the supplying treatment works’ performance, network seeding (including in service reservoirs) and network condition.
    Date: Complete
  2. Using the outputs from the root cause analysis (measure (b)1), develop bespoke mitigation plans (with timescales) for Hockers Lane and Rushmoor Water Supply Zones and associated upstream assets, to achieve the company’s AMP 7 target of 2 or less consumer contacts for discolouration per 1000 population (individually in each zone) by 31 March 2025.
    Date: Complete
  3. Deliver the mitigation plans (created under measure (b)2) to its completion, to achieve 2 or less consumer contacts for discolouration per 1000 population by 31 March 2025 in Hockers Lane Water Supply Zone and Rushmoor Water Supply Zone.
    Date: Complete
  4. Investigate and implement measures to achieve a company average (across all the company’s water supply zones) discolouration consumer contact rate of 0.5 per 1000 population by 31 March 2025.
    Date: Complete

Phase 2 – AMP8 targets

  1. Review and update procedures for investigating consumer contacts for discolouration, sample failures of parameters listed above and water quality discolouration events.
    Date: Complete
  2. Review and revise, as appropriate, the current discolouration risk assessment methodology (including discolouration root-cause analysis) and the current discolouration strategy to reduce the risk of discoloured water in water supply zones. The strategy must be developed in conjunction with relevant stakeholders and aligned to recognised standards of good practise and current industry good practise. The strategy must cover discolouration risks from: treatment works (including optimisation of treatment processes and risk from catchment sources of discolouration related parameters); service reservoirs (including settled deposits); trunk mains; and the zonal network.
    Date: Complete
  3. Using the updated risk assessment methodology and discolouration strategy (measure (b)7), identify an AMP8 target rate for high-risk water supply zones (‘the high-risk water supply zones’) for further investigation and update the appropriate regulation 27 risk assessments. This will need to be proposed to and agreed by the Inspectorate and be in line with the wider industry discolouration performance.
    Date: Complete
  4. Following the agreement of the new AMP8 target of less than 0.94 contacts per 1000 population review the Company’s high-risk water supply zones to update Annex A with any new zones of high discolouration risk and remove any zones no longer deemed high risk.
    Date: Complete
  5. Undertake root cause analysis for the high-risk water supply zones on Annex A to understand the risk of discolouration within these zones and the level of discolouration contact rate per 1000 population.
    Date: 31 August 2025
  6. Using the outputs from the root cause analysis (measure (b)9), develop bespoke programmes of works (with timescales) for the high-risk water supply zones to achieve the Phase 2 (AMP 8) target by 31 March 2030 (‘Phase 2 programmes of works’).
    Date: 31 October 2025
  7. From 2026, on an annual basis, review the Company’s high-risk water supply zones to update Annex A with any new zones of high discolouration risk and remove any zones no longer deemed high risk.
    Date: Annually by 31 January
  8. From 2026, on an annual basis, undertake root cause analysis for the high-risk water supply zones on Annex A to understand the risk of discolouration within these zones and the level of discolouration contact rate per 1000 population.
    Date: Annually by 30 April
  9. From 2026, on an annual basis, using the outputs from the root cause analysis (measure (b)12), develop and update bespoke programmes of works (with timescales) for the high-risk water supply zones to achieve the Phase 2 (AMP 8) target by 31 March 2030 (‘Phase 2 programmes of works’).
    Date: Annually by 30 June
  10. Commence, on a risk prioritisation basis, the Phase 2 programmes of works to achieve the AMP8 target of less than 0.94 contacts per 1000 population by 31 March 2030.
    Date: Commence by 01 May 2025 thereafter, ongoing until its completion by 31 March 2030
  11. Investigate and implement measures to achieve a company average (across all the company’s water supply zones) discolouration consumer contact rate of 0.45 per 1000 population by 31 March 2030.
    Date: Commence by 31 May 2025 thereafter, ongoing until its completion by 31 March 2030
  12. From 2025, on an annual basis, review and update, as necessary, the Company’s risk assessment methodology for discolouration and the Company’s discolouration strategy. These reviews must be completed in conjunction with relevant stakeholders and aligned to recognised standards of good practise and current industry good practise.
    Date: From 2025 at least annually by 30 April (ongoing for the duration of the notice)

Phase 3 – AMP9 Targets

  1. Agree Phase 3 (AMP 9) target company average (across all the company’s water supply zones) discolouration consumer contact rate with the Inspectorate, based on the predicted national average at the time, in any case to be a maximum of 0.3 consumer contacts for discolouration per 1000 population by 31 March 2035.
    Date: 31 March 2029
  2. Investigate and implement measures to achieve the agreed company average discolouration consumer contact rate target (target to be agreed) by 31 March 2035.
    Date: Commence by 01 April 2030 thereafter, ongoing until its completion by 31 March 2035

(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 August 2025
  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 company’s assets, 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 root cause analysis and mitigation plans for Hockers Lane and Rushmoor Water Supply Zones as required under (b)2. Confirm commencement of the mitigation plans.
    Date: Complete
  3. Submit a report outlining the mitigation completed in Hockers Lane and Rushmoor Water Supply Zones (measure (b)3), and across the company (measure (b)4). Outline evidence to show whether the company has met the Phase 1 targets.
    Date: Complete
  4. Outline the review completed under measure (b)7 and provide the updated procedure.
    Date: Complete
  5. Outline the reviews completed under measure (b)6 and provide the updated methodology and discolouration strategy under measure (b)16.
    Date: 31 March 2024, and from 2025 annually on 31 May
  6. Identify the high-risk water supply zones as required under measure (b)8 and (b)11.
    Date: 28 May 2025 and from 2026 annually by 28 February
  7. Outline the findings of the root cause analysis for the high-risk water supply zones as required under measure (b)9 and (b)12.
    Date: 30 September 2025 and from 2026, annually by 31 May
  8. Provide the Phase 2 programmes of works developed under measure (b)10 and (b)13 and confirm commencement and any updates to these programmes.
    Date: 30 November 2025 and from 2026, annually by 31 July
  9. Outline the company wide discolouration measures developed under measure (b)15 and confirm commencement.
    Date: 31 July 2025 and from 2026, annually by 31 May
  10. Submit and agree with the Inspectorate the proposed Phase 2 target.
    Date: Complete
  11. Submit and agree with the Inspectorate the proposed Phase 3 target.
    Date: 30 April 2029
  12. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 30 September 2025
  13. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  14. 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
  15. Submit a final completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 April 2035

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
4 June 2025
Reference: SEW-2023-00001 v2

Zone Reference

Zone Name

Z257

HINDHEAD WATER SUPPLY ZONE

Z308

HOCKERS LANE WATER SUPPLY ZONE

Z009

BURWASH WATER SUPPLY ZONE

Z269

TILMORE WATER SUPPLY ZONE

Z322

HALLING WATER SUPPLY ZONE

Z028

GROOMBRIDGE WATER SUPPLY ZONE

Z303

BEWL WATER SUPPLY ZONE

Z313

CHARING WATER SUPPLY ZONE

Z264

RUSHMOOR WATER SUPPLY ZONE

Z018

CUCKFIELD WATER SUPPLY ZONE

Z309

WEALD WATER SUPPLY ZONE

Z025

HEATHFIELD WATER SUPPLY ZONE

Z268

TILFORD WATER SUPPLY ZONE

Z270

VICTORIA WATER SUPPLY ZONE

Z305

BOXLEY WATER SUPPLY ZONE

Z021

FOLKINGTON WATER SUPPLY ZONE

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