South East Water Limited – Tilford Meads Treatment Works Arsenic
Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)
Reference: SEW-2023-00003
Version Number: 4
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:
|
Asset Name |
Reference |
|---|---|
|
Tilford Meads Treatment Works |
T220 |
|
Tilford Water Supply Zone |
Z268 |
Details of this Notice:
- 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 01 January 2023, which states that there is or has been a significant risk of supplying water from Tilford Meads Treatment Works 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 |
Hazard I D |
|---|---|---|
|
Potential risks to drinking water quality and non-compliance with the Water Supply (Water Quality) Regulations.) |
Arsenic |
T220-TREATMENT-B001A |
|
Potential risks to drinking water quality and non-compliance with the Water Supply (Water Quality) Regulations.) |
Arsenic |
Z268-DISTRIBUTION-B001A |
|
Potential risks to drinking water quality and non-compliance with the Water Supply (Water Quality) Regulations.) |
Arsenic |
Z268-CONSUMER-B001A |
- 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:
- Optimisation of all existing treatment processes.
Date: Ongoing for the duration of this Notice - Operation of all processes within defined normal operating ranges with appropriate triggers, responses and contingency procedures.
Date: Ongoing for the duration of this Notice - Online turbidity and chlorine monitoring with appropriate alarms and failsafe shutdown.
Date: Ongoing for the duration of this Notice - Enhanced monitoring for arsenic at Tilford Meads Treatment Works (and within zones supplied by Tilford treatment works) as defined within the audit strategy.
Date: Ongoing for the duration of this Notice - Continuously review all critical control points and mitigation measures for the duration of this notice with a view to updating the notice with additional measures where required.
Date: Ongoing for the duration of this Notice - Operation of all processes within defined operating ranges with appropriate triggers, responses and contingency procedures.
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:
- Options appraisal for appropriate start up to waste system.
Date: Complete - Inspection and remediation of all boreholes.
Date: 31 March 2025 - Installation of new filter backwash flow meter with appropriate alarm/ control to ensure efficient backwashing of filter media is maintained.
Date: Complete - Installation of appropriate start up to waste system as detailed in output from (b)1.
Date: Complete - Carry out detailed investigation of each of the pressure filters to highlight any recommended remedial work that is required to enhance asset life.
Date: Complete - Installation of new sodium hypochlorite dosing system to cater for pre-chlorination.
Date: Complete - Optimisation of soft start drives for borehole pumps.
Date: Complete - Installation of new pre filter and post filter iron analyser.
Date: Complete - Carry out all remedial work as recommended in measure (b)5.
Date: Complete - Replacement of all filter automated valves and actuators.
Date: Complete - Replacement of all media in all 16 filters. Two filters to be replaced every 6 weeks.
Date: Complete - Installation of new pre filter and post filter chlorine analyser.
Date: Complete
(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: Complete - 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 Tilford Meads Treatment Works, or not to so supply unless the specified conditions below are satisfied:
- Not applicable
Date: 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. - Provide appraisal report for start up to waste system, confirming chosen solution and timeframes for installation and commissioning.
Date: Complete - Provide report following inspection and remediation of all boreholes.
Date: 30 April 2025 - Provide completion report for installation and commissioning of new filter backwash flow meter with appropriate alarm/ control to ensure efficient backwashing of filter media is maintained.
Date: Complete - Provide completion report for installation and commissioning of appropriate start up to waste system.
Date: Complete - Provide report following detailed investigation of each of the pressure filters to highlight any recommended remedial work that is required to enhance asset life.
Date: Complete - Provide completion report for installation of new sodium hypochlorite dosing system to cater for pre-chlorination.
Date: Complete - Provide completion report for optimisation of soft starter drives for borehole pumps.
Date: Complete - Provide completion report for installation and commissioning of new pre filter and post filter iron analyser.
Date: Complete - Provide completion and commissioning report for all remedial work as recommended in measure (b)5.
Date: Complete - Provide completion report for replacement and commissioning of all filters automated valves and actuators.
Date: Complete - Provide completion report for replacement and commissioning of all media in all 16 filters.
Date: Complete - Provide completion report for installation and commissioning of new pre filter and post filter chlorine analyser.
Date: Complete - Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
Date: Complete - 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: 30 April 2026
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).
Nicholas Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs
6 January 2025
Reference: SEW-2023-00003 v4