Undertakings: Southern Water – All Chlorine Booster Station
WATER INDUSTRY ACT 1991: SECTION 19(1)(b)
THE SECRETARY OF STATE FOR ENVIRONMENT, FOOD, AND RURAL AFFAIRS:
- is satisfied that Southern Water “the Company” in supplying water in all zones in connected supply systems supplied by Southern Water chlorine booster stations which may be at risk of exceeding the standards for disinfection byproducts. This means that the Company is likely to contravene its duty in respect of supplying water which meets the Regulations under Section 68(1)(a) of the Water Industry Act 1991 and meets the requirement set in regulation 4(2)(c) of the Water Supply (Water Quality) Regulations 2016 (as amended).
- has notified Southern Water that the Secretary of State is considering making in relation to the Company an enforcement order under Section 18 of the Water Industry Act 1991.
- notes that Southern Water has on 25 June 2019 given an undertaking under Section 19(1)(b)of the Water Industry Act 1991 to take the following steps by the dates shown:
(a)
Ensure that disinfection by-products have been incorporated into the company drinking water safety plan and assessed as hazards as part of the regulation 27 Risk Assessment for the supply systems supplied by the chlorine booster stations.
(b)
- Implement an enhanced monitoring strategy to supplement current regulatory treated water monitoring. Parameters to be monitored include:
- Chlorate
- Trichloromethane (Chloroform)
- Dichlorobromomethane
- Bibromochloromethane
- Tribromomethane (Bromoform)
- Total organic carbon
- The Company will take all reasonable steps to ensure that Regulation 26(2) is not breached and additional steps must be taken to protect public health. If the concentration of disinfection by-products in any water sample exceeds the maximum concentration the Company has agreed with Public Health England’s local Health Protection Units covering the water supply zones listed in the Annex to this Schedule of Works, take all reasonable measures in consultation with the Public Health England to minimise the impact on customers.
- Report breaches of Regulation 26(2) to DWI as part of the water quality events reporting process.
- Ensure the booster station chemical storage, dosing equipment and chlorine monitors are inspected, maintained and calibrated at predefined frequencies, in accordance with manufacturer’s instructions where applicable.
- Use site specific procedures where appropriate, including manual intervention and run to waste.
Measures to be delivered:
(c)
Develop a process to enable the full review and documentation of operational and asset hazards at each chlorine booster station listed in the Annex to this schedule, ensuring compliance with the Water Supply (Water Quality) Regulations.
Date: By 31 July 2019.
This process must include:
- A review of current asset performance.
- A review of site pipework, valves, drainage and sanitary disposal facilities.
- An end to end review of operational and maintenance tasks.
- A review of asset criticality, including single points of failure.
- An assessment of hazard containment and recovery requirements, including run to waste and automated shutdown facilities.
- A review of sampling and online monitoring against good practice.
- A review of contingency planning for the site.
- A review of the use of all consumable materials (e.g. chemicals) used on sites, which are approved under Regulation 31(4) b to ensure the manufacturer’s instructions for use are complied with.
- Specifically, a review of sodium hypochlorite storage and usage against the requirements of BSEN: 901-2013 and any manufacturers’ instructions and national conditions for use.
(d)
Develop a programme of work, including timescales for completing hazard reviews at individual sites. The programme should be kept under regular review and a risk based approach should determine the priority order of sites.
Date: By 31 August 2019.
(e)
Complete a hazard review at each site listed in the Annex to this Schedule; each review to be conducted in accordance with the process specified in section C.
Date: By 31 October 2020.
(f)
Implement as soon as practicable short to medium term mitigation where required to control any uncontrolled hazards identified from reviews conducted following the process specified in section C above.
Date: As required for the individual assets using a risk-based approach.
(g)
Plan a programme of permanent measures required to address all uncontrolled hazards identified from the programme specified in in section d for all chlorine booster stations as listed in the Annex to this Schedule.
Date: By 31 March 2021.
(h)
Implement the planned programme of work identified for each booster station in section G.
Date: By 31 March 2025.
Auditing:
(i)
- Define a strategy for auditing the effectiveness of the measures made operational above, to include an annual audit of operator and maintenance tasks completed at each works.
- Implement the audit strategy defined above.
Reporting:
(j)
Provide a progress report annually by 31 January and against the following milestones:
- Provide an audit strategy.
Date: By 30 November 2019. - Provide an action plan to mitigate risk identified for all booster stations.
Date: For the duration of the notice.
(k)
Review the risk assessments as required by Regulation 27 and subsequently submit new or revised regulation 28 reports accompanied by a signed board level declaration.
Date: As required and by 21 October 2021.
(l)
Provide a final report to the Drinking Water Inspectorate on the efficacy of the remedial measures taken as part of the Action Plan. Include as evidence of closure for this scheme appropriate documentation to confirm that the actions set out in this Schedule of Work have been taken.
Date: By 31 March 2026.
- is satisfied that Southern Water has given and is complying with an undertaking to take all such steps as appear to the Secretary of State for the time being to be appropriate to secure or facilitate compliance with the requirement of regulation 4(2)(c) of the Water Supply (Water Quality) Regulations 2016 (as amended).
Authorised by the Secretary of State to sign in that behalf
Milo Purcell
Deputy Chief Inspector
Drinking Water Inspectorate
DWI Ref No: SRN-2019-00003
24 October 2019
ANNEX TO SCHEDULE
SOUTHERN WATER SERVICES LTD
Undertaking in respect of disinfection by-products
Assets Affected/Asset name | Water Quality zones supplied | Zone Reference |
|---|---|---|
Newgate WBS | Baldslow | ZS528 |
Rownhams | Otterbourne Direct | ZH508 |
Chale WBS | Sandown / Central Downs Combined | ZI512 |
Maze Hill WBS | Baldslow | ZS528 |
Warren Fairlight WBS | Fairlight | ZS529 |
Lyndhurst | Rownhams_01 | ZH527 |
Fairlight Old WBS | Fairlight | ZS529 |
Broadfields WBS | Alvington High Level | ZI501 |
Downsend WBS | Alvington High Level | ZI501 |
Totland | Alvington high Level | ZI501 |
Udimore WBS | Fairlight | ZS529 |
High Park Stanmer WBS | Brighton North | ZS535 |
Cocking WBS | Cocking | ZS533 |