Severn Trent Water Limited – Service Reservoirs and Treated Water Tanks Inspections
Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)
Reference: SVT-2022-00004
Version Number: 2
Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Severn Trent Water Limited, with registered number 02366686 (hereinafter called ‘the Company’).
Assets Affected:
- All the chlorine contact tanks, service reservoirs and treated water tanks (hereafter collectively referred to as ‘tanks’) used to supply water for regulation 4(1) purposes by the Company.
Details of this Notice:
- The Drinking Water Inspectorate (‘the Inspectorate’) has received a set of regulation 28(1) reports of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated 21 October 2021, which state that there is or has been a significant risk of supplying water from its tanks (and associated assets as applicable) that could constitute a potential danger to human health or could be unwholesome.
- 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 |
| To address the potential risks of ingress and microbial re-growth. | Coliform bacteria |
| To address the potential risks of ingress and microbial re-growth. | Escherichia coli (E. coli) |
| To address the potential risks of ingress and microbial re-growth. | Clostridium perfringens |
| To address the potential risks of ingress and microbial re-growth. | Enterococci |
| To address the potential risks of ingress and microbial re-growth. | Colony Counts |
| To address the potential risks of ingress and microbial re-growth. | Residual Disinfectant – Total Chlorine |
| To address the potential risks of ingress and microbial re-growth. | Residual Disinfectant – Free Chlorine |
- 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:
- Operate all tanks in accordance with current company policy, standards and procedures, that align to recognised standards of good practice.
Date: Ongoing for the duration of this Notice - Maintain risk based enhanced (in addition to routine regulatory sampling) sampling for any tanks listed in Annex 1. This must include, as a minimum, colony counts, E. coli, Clostridium perfringens and coliforms.
Date: Ongoing for the duration of this Notice - Maintain proactive external site inspections, grounds maintenance, site security and asset maintenance. This must include periodic inspections of hatches, seals, redundant assets, sample taps, overflows, washouts, and air valves.
Date: Ongoing for the duration of this Notice - Maintain appropriate contingency plans (including liaison with relevant stakeholders as appropriate) to protect human health.
Date: Ongoing for the duration of this Notice - 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
(b) To review, revise or make operational the following measures, by the dates specified in each case:
- Develop a programme of works (that includes cleaning, robust ingression testing (e.g. flood/inundation) and completion of any tank remedial work required), using a risk-based approach, to carry out physical internal inspections of all tanks listed in Annex 1.
Date: 31 August 2022 - Review Annex 1 on at least a biannual basis to ensure that all tanks that have not been cleaned and physically internally inspected in the last 10 years or more, are identified within the Annex, unless already specified in SVT-2020-00008. Update the regulation 28(1) risk assessment as appropriate.
Date: Biannually by 31 May and 30 November - Within 3 months of the identification of a new tank requiring addition to Annex 1 (following a review completed under measure (b)2), update the programme of works (that includes cleaning, robust ingression (e.g. flood/inundation) testing and completion of any remedial work required) to include the physical internal inspections for the identified tank.
Date: Annually by 31 August - Carry out an optioneering study to determine required enabling work for the isolation of the tanks listed in Annex 1.
Date: 31 July 2022 - Following the review in (b)4, develop a risk-based programme of works for the enabling work required.
Date: 31 December 2022 - Review and update the overall programme of work to incorporate (b)1 and (b)5.
Date: 31 December 2022 - Implement the programme of works developed in (b)1. (Including any updates completed under measure (b)3) to completion. Maintain appropriate documentation of any remedial work completed.
Date: from 31 August 2022 until revocation of the notice. - Conduct a critical review of the effectiveness of the Company’s scheduling and delivery of internal inspections of tanks. Identify and implement measures (as required) to address the findings of the critical review.
Date: 30 September 2022 - Implement the measures identified under (b)6 above.
Date: Ongoing for the duration of this notice until 31 July 2026 - Develop a risk-based approach to determine the cleaning and physical internal inspection frequency of all Company tanks, to include as a minimum: Time since last inspected; Date of construction/age; Materials of construction/tank design; Water quality history (to include as a minimum E. coli, coliforms, and colony counts); Turnover and tank hydraulics; Points of potential ingress (hatches, seals, redundant assets, overflows, washouts, and air valves); Sample tap condition, tapping points, sample lines and material and any other risks related to individual tanks.
Date: 31 October 2022 - Implement the risk-based approach to cleaning and physical internal inspections of all tanks within the company’s supply area, developed under measure (b)10.
Date: 30 November 2022
(c) To audit whether the measures have been effective by the following means:
- Define an audit strategy to monitor the effectiveness of the measures specified in sections (a) and (b).
Date: 31 October 2022 - 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 tanks, or not to so supply unless the specified conditions below are satisfied:
- 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:
- Provide a progress report annually.
Date: by 31 January each year. - Submit the programme of work for the physical internal inspection for tanks listed in Annex 1 as required under measure (b)1.
Date: 30 September 2022 - Provide a report summarising the outcomes of the Optioneering Study produced as required in measure (b)4
Date: 31 August 2022 - Submit the overall programme of works as required under measure (b)6
Date: 31 January 2023 - Submit a list of any newly identified tanks to be included in Annex 1, as required under measure (b)2. For any tanks listed in Annex 1, completed in advance of 31 July 2027, submit evidence demonstrating satisfactory completion of the internal inspection, ingression (e.g. inundation/flood) testing, and any remedial work completed with an accompanying regulation 28(1) report for the tank and an updated Annex 1 for this notice.
Date: Annually by 30 June - Submit any updated programme of works for the physical internal inspection of any tanks identified under measure (b)2. (as required under measure (b)3).
Date: Annually by 30 September - Confirm completion of the programme of works (measure (b)6).
Date: 31 August 2026 - Outline the findings of the critical review and any resulting identified measures (measure (b)8).
Date: 31 October 2022 - Outline the risk-based approach developed under measure (b)5.
Date: 31 January 2023 - Confirm implementation of the risk-based approach (measure (b)11)
Date: 31 December 2022 - Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
Date: 30 November 2022 - Submit any revisions of the audit strategy produced under measure (c)2.
Date: Within 1 month of a revision - 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 - Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
Date: 31 July 2027
Further Details of this Notice:
- Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
- 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.
- 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
21 September 2022
Reference: SVT-2022-00004