Southern Water Services Limited – Borehole Asset Health Refurbishments

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

Reference: SRN-2026-00004

Version Number: v1

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Southern Water Services Limited, with registered number 02366670 (hereinafter called ‘the company’).

Assets Affected:

• All Southern assets listed in Appendix A, Appendix B, Appendix C, and the associated supply systems.

Details of this Notice:

1. The Drinking Water Inspectorate (‘the Inspectorate’) has received various regulation 28(1) reports of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the company dated 28 February 2022, 15 October 2025 and 28 July 2026, which states that there is or has been a significant risk of supplying water from the sites listed in the Appendices (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
Structural integrity of asset at risk	No Supply	135887
Insufficient water supply to downstream consumers	No Supply	135888
Compromised disinfection process	Turbidity	70413
Microbiological contamination due to ingress	Total Coliforms	54081
Microbiological contamination due to ingress	E. coli	54082
Microbiological contamination due to ingress	Clostridium Perfringens	54079
Microbiological contamination due to ingress	Enterococci	54083

Table 1: Table of the hazards, hazardous events, and/or parameters covered by this Notice, including the Hazard I D numbers and the description of risks.

4. 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. Undertake scheduled Southern Water operator site inspections of borehole headworks at the required frequency.
   Date: Ongoing for the duration of this Notice.
   
2. Undertake grounds maintenance at the standard frequency.
   Date: Ongoing for the duration of this Notice.
   
3. Carryout maintenance tasks at groundwater abstraction assets in accordance with Southern Water standards.
   Date: Ongoing for the duration of this Notice.
   
4. Undertake raw water sampling at the frequency defined by the annual Southern Water Sampling Programme.
   Date: Ongoing for the duration of this Notice.
   
5. Ensure the operating plan for the water supply works is followed where blending of individual boreholes is required to maintain compliance.
   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. Programme the refurbishment works to be completed at the raw water abstraction assets in accordance with the Ofwat final asset health determination and list those abstraction assets to be refurbished in AMP8 and those to be carried forward to AMP9 in an update to Appendix A.
   Date: 31 March 2027.
   
2. Complete the refurbishment and return to service of the raw water abstraction assets listed for completion in AMP8 in Appendix A.
   Date: 31 March 2031.
   
3. Programme the survey and associated enabling works at the assets listed in Appendix B.
   Date: 31 March 2027.
   
4. Complete the programme of surveys and associated enabling works at the raw water abstraction point listed in Appendix B.
   Date: 31 March 2030.
   
5. Design a programme of targeted assessments and appropriate surveys of wells and assets listed in Appendix C.
   Date: 31 March 2027.
   
6. Complete the submitted programme of targeted assessments and appropriate surveys at the wells and assets listed in Appendix C to determine the long term strategy for wells and assets.
   Date: 31 March 2030.
   
7. Where there is a change to any of the programmes of works listed in measures b(1), b(3), or b(5), inform the Inspectorate, detailing the reason for the change.
   Date: Within one month of the proposed change being known.
   

(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 December 2026
   
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 the sites listed in the Appendices, or not to so supply unless the specified conditions below are satisfied:

1. N/A

(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. Provide an annual report on progress with b milestone actions.
   Date: by 30 April each year.
   
3. Provide a risk-based programme of works for the refurbishment works to be completed at the raw water abstraction assets, identifying those for completion in AMP8 and those to be carried forward to AMP9 in an updated Appendix A.
   Date: 30 April 2027.
   
4. Provide a report on the completion of refurbishment and return to service of the boreholes listed for completion in AMP8 in Appendix A.
   Date: 30 April 2031.
   
5. Provide a risk-based programme of works for the survey and associated enabling works at the assets listed in Appendix B.
   Date: 30 April 2027.
   
6. Provide a report on the findings from the programme of surveys and associated enabling works at the raw water abstraction point listed in Appendix B detailing any proposed works to be carried out in AMP9 to mitigate water quality or sufficiency risks.
   Date: 30 April 2030.
   
7. Provide a programme of works for the targeted assessments and appropriate surveys of the wells and assets listed in Appendix C.
   Date: 30 April 2027.
   
8. Provide a report on the findings from the programme of targeted assessments and appropriate surveys at the wells and assets listed in Appendix C detailing the long term strategy, and any proposed works required to be carried out in AMP9 to mitigate water quality or sufficiency risks.
   Date: 30 April 2030.
   
9. Provide an updated programme where there is a change to any of the programmes of works listed in measures b(1), b(3), or b(5).
   Date: Within one month of the change being made to the programme.
   
10. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 31 January 2027
    
11. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision.
    
12. 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.
    
13. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 30 April 2032.

Further Details of this Notice:

5. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
   
6. 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.
   
7. 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 October 2026
Reference: SRN-2026-00004

Appendix A

Asset ref	Asset name	Supply system ref	Supply system name
AH038	Andover Borehole 4 UGS	Y001	Hampshire North
AS016	Arundel Borehole 1 UGS	Y009	Worthing
AH039	Barton Stacey Borehole 1 UGS	Y011	Winchester
AH040	Barton Stacey Borehole 2 UGS	Y011	Winchester
AIXX1	Birchmore Blackwater BH 1B UGS	Y004	Isle of Wight
AI002	Bowcombe Borehole UGS	Y004	Isle of Wight
AS078	Broadwater Borehole 48 Inch	Y009	Worthing
AK002	Bush Road Cuxton Borehole 3 UGS	Y016	Medway West
AK043	Capstone Chalk Borehole 1 UGS	Y015	Medway East
AK044	Capstone Greensand Borehole 1 UGS	Y015	Medway East
AS021	Findon Road Worthing Borehole 1 UGS	Y009	Worthing
AS051	Findon Road Worthing Borehole 2 UGS	Y009	Worthing
AIXX3	Lower Yard Godshill Borehole 1A UGS	Y004	Isle of Wight
AK010	Luddesdown Chalk Borehole 2 UGS	Y016	Medway West
AK026	Martin Gorse Borehole 1 UGS	Y010	Thanet
AK070	Matts Hill Hartlip Borehole 4 UGS	Y015	Medway East
AK028	Minster IOT Borehole B UGS	Y010	Thanet
AS091	Northbrook Worthing Borehole 2 UGS	Y009	Worthing
AK072	Northfleet Chalk Borehole 2 UGS	Y016	Medway West
AH051	Overton Borehole 1 UGS	Y001	Hampshire North
AS030	Shoreham Borehole 1 UGS	Y007	Brighton
AS056	Shoreham Borehole 2 UGS	Y007	Brighton
TBC	Sompting Borehole 1 UGS	Y007	Brighton
AS095	Sompting Borehole 2 UGS	Y007	Brighton
AS022	Stanhope Lodge Worthing BH UGS	Y009	Worthing
AH056	Timsbury Well 3 UGS	Y012	Hampshire Rural
AS017	Warningcamp Borehole 1 UGS	Y009	Worthing
AK035	Woodnesborough Borehole 3 UGS	Y010	Thanet

Appendix B

Asset ref	Asset name	Supply system ref	Supply system name
AS071	Angmering Borehole 1 UGS	Y009	Worthing
AI024	Carisbrooke Borehole 1 UGS	Y004	Isle of Wight
AI025	Carisbrooke Borehole 2 UGS	Y004	Isle of Wight
AS019	Clapham Borehole UGS	Y009	Worthing
AH018	East Woodhay Borehole 2 UGS	Y005	Kingsclere
AK058	Flemings Road Woodnesborough Borehole A UGS	Y010	Thanet
AH020	Horsebridge Borehole 1 UGS	Y012	Hampshire Rural
AH034	Horsebridge Borehole 2 UGS	Y012	Hampshire Rural
AH044	Ibthorpe Borehole 1 UGS	Y001	Hampshire North
AH045	Ibthorpe Borehole 2 UGS	Y001	Hampshire North
AK009	Keycol Borehole 1 UGS	Y015	Medway East
TBC	Northfleet Greensand Borehole 4 UGS	Y016	Medway West
TBC	Rainham Mark Borehole 1 UGS	Y015	Medway East
TBC	Rogate Observation BH TBH	Y008	Sussex North
AH057	Totford Borehole 1 UGS	Y011	Winchester
AH058	Totford Borehole 2 UGS	Y011	Winchester
AH006	Twyford Moors Borehole G UGS	Y013	Southampton East
AH032	Whitchurch Borehole 1 UGS	Y001	Hampshire North
AH017	Whitchurch Borehole 2 UGS	Y001	Hampshire North

Appendix C

Asset ref	Asset name	Supply system ref	Supply system name
AS075	Balsdean Rottingdean Well 3 UGS	Y007	Brighton
AI027	Bowcombe Well UGS	Y004	Isle of Wight
TBC	Brede Well 2 ACS	Y003;Y016	Hastings;Medway West
AS063	Brede Well 3 UGS	Y003;Y016	Hastings;Medway West
TBC	Brede Well 4 ACS	Y003;Y016	Hastings;Medway West
AK056	Deal Well 1 UGS	Y010	Thanet
AK004	Fawkham Longfield Well UGS	Y016	Medway West
AS032	Goldstone Hove Well 3 UGS	Y007	Brighton
TBC	Haslingbourne Well 3 UGS	Y008	Sussex North
AKXX2	Highsted Well 3 UGS	Y015	Medway East
AI009	Knighton Chalk Well UGS	Y004	Isle of Wight
TBC	Knighton Mill Well UGS	Y004	Isle of Wight
AS035	Lewes Road Brighton Well UGS	Y007	Brighton
AK025	Lord of The Manor Well 1 UGS	Y010	Thanet
TBC	Martin Mill Well 1 ACS	Y010	Thanet
TBC	Martin Mill Well 2 ACS	Y010	Thanet
TBC	Northfleet Chalk Well 3 ACS	Y016	Medway West
AH050	Otterbourne Well E UGS	Y013	Southampton East
TBC	Otterbourne Well F UGS	Y013	Southampton East
AS008	Steyning Upper Beeding Well 3 UGS	Y008	Sussex North
TBC	Strood Access Well ACS	Y016	Medway West
TBC	Timsbury Borehole C ACS	Y012	Hampshire Rural
TBC	Timsbury Borehole D ACS	Y012	Hampshire Rural
TBC	Timsbury Borehole E ACS	Y012	Hampshire Rural
TBC	Timsbury Shaft 4 ACS	Y012	Hampshire Rural
TBC	Timsbury Shaft 5 ACS	Y012	Hampshire Rural
TBC	Timsbury Well 1 ACS	Y012	Hampshire Rural
TBC	Timsbury Well 2 ACS	Y012	Hampshire Rural
TBC	Timsbury Woodland ACS	Y012	Hampshire Rural
AK083	Wingham Well 1 UGS	Y010	Thanet
AK085	Wingham Well 3 UGS	Y010	Thanet