South East Water Limited – Pembury Water Treatment Works_Raw Water Treatment

Notice under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 (as amended)

Reference: SEW-2024-00006

Version Number: 1

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
Pembury Treatment Works	T013

Table 1: List of assets affected and associated reference numbers

Details of this Notice:

1. 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 September 2024, which states that there is or has been a significant risk of supplying water from Pembury water treatment works (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 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.	Total Coliforms E. coli Enterococci Clostridium Colony Count Residual disinfectant – free Residual disinfectant – total Turbidity Iron Manganese Aluminium Pesticides – total	T013-TREATMENT-C001 T013-TREATMENT-C002 T013-TREATMENT-C003 T013-TREATMENT-C004A T013-TREATMENT-C007 T013-TREATMENT-C009 T013-TREATMENT-C010 T013-TREATMENT-A002 T013-TREATMENT-A022 T013-TREATMENT-A023 T013-TREATMENT-A021 T013-TREATMENT-B010

Table 2: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.

3. 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. Optimisation of all existing treatment processes. Date: Ongoing for the duration of this Notice
2. Operation of all processes within defined normal operating ranges with appropriate triggers, responses and contingency procedures.  
   Date: Ongoing for the duration of this Notice
3. Maintain annual visual checks of the aeration stage at Pembury Works.
   Date: Ongoing for the duration of this Notice
4. Complete quarterly jar testing of raw and interstage treated water to verify current treatment processes are optimised.
   Date: Ongoing for the duration of this Notice
5. Undertake enhanced monitoring of the ongoing pesticide performance to understand the loading entering the raw water reservoir.
   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 a full clean and assessment of the aerator at Pembury works.
   Date: Complete
2. Complete an assessment of the pesticide concentrations at all inlets and inlet flows into to the raw water reservoir to build a full picture of the pesticide loading entering the Reservoir.
   Date: 31 October 2025
3. Complete the installation and commissioning of sample tappings above the DAFF filters to enable effective monitoring of the clarification stage of treatment. Date: Complete
4. Complete the installation and commissioning of new DAFF scraper brackets. Date: 31 January 2025
5. Confirm the infrastructure chosen to enable accurate flow and turbidity monitoring with alarm and shutdown capability. Date: Complete
6. Complete the Installation and commissioning of the chosen infrastructure required to enable accurate flow and turbidity monitoring with alarm and shutdown capability. Date: 31 March 2025
7. Complete the full desludging of the sludge lagoons. Date: 30 June 2025
8. Complete an assessment of the condition and operation of the sludge lagoons. Date: 30 June 2025
9. Complete the remedial works highlighted in the sludge lagoons’ condition assessment. Date: 31 December 2025
10. Compile a programme of regular planned inspection tasks for the sludge lagoons to ensure they remain in satisfactory condition. Date: Complete
11. Complete a report on the feasibility study carried out on water quality, site resilience, treatment works capability, asset health and asset performance. Date: 31 March 2025
12. Complete the installation and commissioning of a new contact tank. Date: 30 September 2028
13. Complete the upgrading works of the boosters and the replacement of the MCC at Lilley Farm. Date: 30 September 2027
14. Complete the maintenance work on the springs network. Date: 30 September 2028
15. Complete the upgrading of the GAC treatment. Date: 30 September 2028
16. Complete the enlargement to the capacity of the settlement tank. Date: 30 September 2028
17. Complete the installation and commissioning of the new borehole at Matfield. Date: 30 September 2028
18. Complete the water quality, site resilience, treatment works capability, asset health and asset performance improvements required in the company’s Pembury works feasibility study (measure (b)11). Date: 30 March 2030

(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 March 2025
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 Pembury Treatment Works, 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. Submit a completion report for the full clean and assessment of the aerator at Pembury works, as specified in measure (b)1.
   Date: 31 January 2025
3. Submit the completed assessment of the pesticide concentrations at all inlets and inlet flows into to the raw water reservoir to build a full picture of the pesticide loading entering the Reservoir, as specified in measure (b)2.
   Date: 30 November 2025
4. Submit a completion report confirming the installation and commissioning of sample tappings above the DAFF filters to enable effective monitoring of the clarification stage of treatment, as specified in measure (b)3.
   Date: 31 January 2025
5. Submit a completion report confirming the installation and commissioning of new DAFF scraper brackets, as specified in measure (b)4. Date: 28 February 2025
6. Submit a report confirming the chosen infrastructure chosen to enable accurate flow and turbidity monitoring with alarm and shutdown capability, as specified in measure (b)5.
   Date: Complete
7. Submit a completion report confirming the Installation and commissioning of the chosen infrastructure required to enable accurate flow and turbidity monitoring with alarm and shutdown capability, as specified in measure (b)6.
   Date: 30 April 2025
8. Submit a report confirming the completion of the full desludging of the sludge lagoons, as specified in measure (b)7. Date: 31 July 2025
9. Submit the completed assessment of the condition and operation of the sludge lagoons, as specified in measure (b)8. Date: 31 July 2025
10. Submit a report confirming the completion of the remedial works highlighted in the sludge lagoons’ condition assessment, as specified in measure (b)9. Date: 31 January 2026
11. Submit the programme of regular planned inspection tasks for the sludge lagoons to ensure they remain in satisfactory condition, as specified in measure (b)10. Date: Complete
12. Submit the completed report on the feasibility study carried out on water quality, site resilience, treatment works capability, asset health and asset performance, as specified in measure (b)11. Date: 30 April 2025
13. Submit a report confirming the completion and commissioning of the new contact tank, as specified in measure (b)12. Date: 31 October 2028
14. Submit a report confirming the completion of the upgrading works of the boosters and the replacement and commissioning of the MCC at Lilley Farm, as specified in measure (b)13. Date: 31 October 2027
15. Submit a report confirming the completion of the maintenance work on the springs network, as specified in measure (b)14. Date: 31 October 2028
16. Submit a report confirming the completion of the upgrading of the GAC treatment, as specified in measure (b)15. Date: 31 October 2028
17. Submit a report confirming the completion of the enlargement to the capacity of the settlement tank, as specified in measure (b)16. Date: 31 October 2028
18. Submit a report confirming the completion of the Pembury works water quality, site resilience, treatment works capability, asset health and asset performance improvements reported in the feasibility study, as specified in measures (b)18 and (e)12. Date: 30 April 2030
19. Submit a report confirming the completion of the installation and commissioning of the new borehole at Matfield, as specified in measure (b)17. Date: 31 October 2028
20. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 30 April 2025
21. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
22. 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
23. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 31 May 2031

Further Details of this Notice:

4. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
5. 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.
6. 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
13 January 2025
Reference: SEW-2024-00006