Notice of regulation: Hafren Dyfrdwy Cyfyngedig – New Hall DSR

Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2018

Reference: HDC-2022-00004

Version Number: 1

Water undertaker as appointed under section 6 of The Water Industry Act 1991 (as amended): Hafren Dyfrdwy Cyfyngedig, with registered number 03527628 (hereinafter called ‘the Company’). 

Assets Affected:

  • R48B – New Hall Wrexham DSR
  • Z05 Glyndwr South

Details of this Notice:

  1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a set of regulation 28(1) reports of the Water Supply (Water Quality) Regulations 2018 (‘the Regulations’) from the Company dated between 06 October 2020 and 04 October 2021, which state that there is or has been a significant risk of supplying water from New Hall Wrexham DSR (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 Welsh Ministers, under regulation 28(4) for the assets listed above, for risks associated with:

Description of Risk

Hazard / Hazardous Event / Parameter

Hazard I D

To address the risk of ingress contamination and microbial growth.

Total Coliforms (confirmed)

R48B-11135-S-H035-C001-23P

To address the risk of ingress contamination and microbial growth.

E. coli (confirmed)

R48B-11135-S-C111-C002-23Q

To address the risk of ingress contamination and microbial growth.

Clostridium perfringens (confirmed)

R48B-11135-S-C111-C004A-2YX

To address the risk of ingress contamination and microbial growth.

Enterococci (confirmed)

R48B-11135-S-C111-C003-2Q2

To address the risk of ingress contamination and microbial growth.

Residual Disinfectant – Total chlorine

R48B-11135-S-H047-C010-1R3

To address the risk of ingress contamination and microbial growth.

Residual Disinfectant – Free Chlorine

R48B-11135-S-H047-C009-161

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. Operate New Hall DSR in accordance with company policy, standards, and procedures, aligning with recognised standards of good practice.
    Date: Ongoing for the duration of this notice
  2. Carry out investigatory sampling in response to any microbiological exceedances.
    Date: Ongoing for the duration of this notice
  3. Maintain twice weekly (as a minimum) enhanced sampling (in addition to statutory sampling) for New Hall DSR. This must include, as a minimum E. coli, and Total coliforms.
    Date: Ongoing for the duration of this notice
  4. Maintain proactive external site inspections, grounds maintenance, site security and asset maintenance, including periodic inspections of hatches, seals, redundant assets, sample taps, overflows, washouts, and air valves.
    Date: Ongoing for the duration of this notice
  5. Maintain an appropriate contingency plan for New Hall DSR (including liaison with relevant stakeholders as appropriate), in the event of the site needing to be removed from supply to protect human health.
    Date: Ongoing for the duration of this notice
  6. Keep under review residual chlorine concentrations to ensure appropriate set points and trigger values are in place to prevent a deterioration of drinking water quality.
    Date: Ongoing for the duration of this notice
  7. Maintain records and evidence of the identification, decision making, and completion of remedial work at New Hall DSR, to ensure a robust audit trail.
    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. Complete the replacement of the intelligent membrane at New Hall DSR with a non-intelligent membrane, in line with Company standards.
    Date: 31 August 2022
  2. Produce a plan of the mitigation actions required to remove New Hall DSR reservoir from supply in the event of an emergency. Update the regulation 27 risk assessments to reflect this risk.
    Date: 30 September 2022
  3. Complete the outline design for the enabling works required to isolate New Hall DSR.
    Date: 31 July 2023
  4. Confirm the expected start date for construction of the agreed solution.
    Date: 31 October 2023
  5. Complete the enabling works required to isolate New Hall DSR.
    Date: 31 October 2024
  6. Isolate New Hall DSR and complete a physical internal inspection including flood test.
    Date: 31 January 2025
  7. Complete the clean and any remedial work required at New Hall DSR.
    Date: 31 July 2025

(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 October 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 New Hall DSR, 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 and provide evidence of the replacement of the intelligent membrane at New Hall DSR, as specified in (b)1.
    Date: 30 September 2022
  3. Provide the plan of the mitigation actions required to remove New Hall DSR reservoir from supply in the event of an emergency.
    Date: 31 October 2022
  4. Provide a report summarising the outline design for the enabling works required at New Hall DSR, as specified in (b)3.
    Date: 31 August 2023
  5. Confirm the expected start date for construction of the agreed solution.
    Date: 30 November 2023
  6. Provide a report confirming and evidencing the completion of the enabling works required to isolate New Hall DSR.
    Date: 30 November 2024
  7. Confirm New Hall DSR has been isolated from supply for internal inspection.
    Date: 28 February 2025
  8. Provide a report confirming completion of any remedial work required at New Hall DSR including confirmation of clean and return to supply.
    Date: 31 August 2025
  9. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 30 November 2022
  10. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  11. 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
  12. Submit a satisfactory completion report satisfactory completion of the physical internal inspection, flood test, and any remedial work required, accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 September 2026

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 Welsh Ministers, 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 Welsh Ministers
25 August 2022
Reference: HDC-2022-00004 (V1)

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