Anglian Water Services Limited – Great Wratting Water Treatment Works and Keddington Water Treatment Works
Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)
Reference: ANH-2020-00001
Version Number: 8
Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Anglian Water Services Limited, with registered number 02366656 (hereinafter called ‘the Company’).
Assets Affected:
- Great Wratting WTW – TGRW2
- Kedington WTW – TKED
- Bury St Edmunds PWSZ – ZSS07
- Haverhill PWSZ – ZSS23
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 1 March 2020, which states that there is or has been a significant risk of supplying water from Great Wratting Water Treatment Works (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 |
Hazard I D |
|---|---|---|
|
Failure of or no treatment (PCV breach) |
Metaldehyde |
ANH-TGRW2-P226-TR0841 |
|
Operational Risk |
Total Pesticides |
ANH-TGRW2-B010-TR3425 |
|
Failure of or no treatment (PCV breach) |
Manganese |
ANH-TGRW2-A023-TR0796 |
|
Failure of or no treatment (PCV breach) |
Iron |
ANH-TGRW2-A022-TR0744 |
|
Operational Risk |
Taste |
ANH-TGRW2-A004-TR3426 |
|
Operational Risk |
Odour |
ANH-TGRW2-A003-TR3424 |
- 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:
- Regular review and update of groundwater risk assessments.
Date: Ongoing for the duration of this Notice - Raw water metaldehyde trend graphs to be regularly updated and metaldehyde will be assessed as a hazard as part of the regulation 27 risk assessment for the supply system supplied by Great Wratting Water Treatment Works (WTW), according to a Drinking Water Safety Plan approach.
Date: Ongoing for the duration of this Notice - Use of Kedington borehole No. 1 to provide standby support, at a reduced flowrate, until completion of the additional control measures at Kedington WTW.
Date: Ongoing for the duration of this Notice - Operational and regulatory monitoring for metaldehyde in the raw and final water at Great Wratting WTW and Kedington WTW (when this is commissioned).
Date: Until the completion of measure (b)5. - Exceedances investigated in line with company procedures.
Date: Ongoing for the duration of this Notice - Implement an enhanced monitoring strategy for metaldehyde, to include the monitoring of all high-risk raw water sources and associated final waters on a weekly basis, to supplement the current regulatory final water monitoring.
Date: Ongoing for the duration of this Notice - The company will take all reasonable steps necessary must be taken to protect public health. If the metaldehyde concentration in any final water sample exceeds 10 µg/l, the maximum deviation of quality values that the Company has agreed with Public Health England, reasonable measures will be taken to protect public health in consultation with local health professionals.
Date: Ongoing for the duration of this Notice - Report regulatory exceedances of the standards for the metaldehyde parameter to DWI, as part of current monthly exception reporting process.
Date: Ongoing for the duration of this Notice - Continually appraise the risk of metaldehyde and total pesticides as a hazard as part of the regulation 27 Risk Assessment for the supply systems supplied by Great Wratting WTW, according to a Drinking Water Safety Plan approach, and ensure that regulation 28 documents are regularly reviewed, and updates provided as necessary.
Date: Ongoing for the duration of this Notice - Support any voluntary initiatives to influence metaldehyde usage in the catchments feeding Great Wratting WTW, taking a risk-based approach. In particular, engage with and provide data to the Environment Agency and other relevant stakeholders, as required and on a regular basis.
Date: Ongoing for the duration of this Notice - Complete enhanced surveillance of waters from Kedington borehole to monitor odour risks and inform any required immediate action.
Date: Ongoing until completion of measure (b)4. - Complete enhanced surveillance of waters from Kedington borehole to ensure levels of iron and manganese are within the treatment capability of Great Wratting WTW.
Date: Ongoing until completion of measure (b)5.
(b) To review, revise or make operational the following measures, by the dates specified in each case:
- Complete the planning, design and procurement arrangements to provide a new low metaldehyde source for replacement/blending with the high yielding Wixoe source.
Date: Complete - Complete the planning, design and procurement arrangements for uprating the treatment at Kedington WTW, as it has been identified that to ensure low metaldehyde water the new source is expected to have higher iron and manganese concentrations than the sources feeding to Great Wratting WTW currently exhibit.
Date: Complete - Complete construction, installation and commissioning of the new low metaldehyde source and uprated treatment designed under measure (b)2.
Date: Complete - Complete the installation and commissioning of sodium bisulphite dosing (to mitigate the risk of hydrogen sulphide odour) to form part of the treatment process for water from Kedington borehole.
Date: Complete - Following the completion of measure (b)4, recommission the low metaldehyde blend (via the uprated treatment and sodium bisulphite dosing at Kedington WTW) from Kedington borehole to enable full operational use of Great Wratting WTW. To include interlocks and controls to manage the blend of the two sources.
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 Great Wratting WTW or Kedington WTW, or not to 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. - Report to evidence the installation and commissioning of the sodium bisulphite dosing to treat water from Kedington borehole as required under measure (b)4.
Date: Complete - Report to evidence the recommissioning of the new low metaldehyde source and uprated treatment as required under measure (b)5.
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: 8 October 2024
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
8 May 2024
ANH-2020-00001 V8