Notice of regulation: Portsmouth Water Limited – Itchen Water Treatment Works

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

Reference: PRT-2021-00003

Version Number: 1

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended):
Portsmouth Water Limited, with registered number 02536455 (hereinafter called ‘the Company’).

Assets Affected:

• TITCH – Itchen Water Treatment Works 
• RHH1 – Hoads Hill No 1 Reservoir  
• RHH2 – Hoads Hill No 2 Reservoir  
• RHH3 – Hoads Hill No 3 Reservoir  
• ZHH1 – Hoads Hill North Supply Zone  
• ZHH2 – Hoads Hill East Supply Zone  
• ZHH3 – Hoads Hill West Supply Zone
• ZLO1 – Lovedean Supply Zone  
• ZNE1 – Nelson Supply Zone 
• YWSP-HSH (supply system reference) 

Details of this Notice

1. The Drinking Water Inspectorate (‘the Inspectorate’) has received a number of regulation 28(1) reports of the Water Supply (Water Quality) Regulations 2016 (as amended) (‘the Regulations’) from the Company dated 18 October 2021, which state that there is or has been a significant risk of supplying water from Itchen 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:

Hazard, Hazardous Event, or Parameter	Hazard ID	Description of Risks
Chemical dosing – failure to administer the correct dose – Aluminium	PRT/HSH/TITCH/T10.3.1	Failure to optimise poly-aluminium chloride dosing resulting in excessive carry over into downstream assets.
Cryptosporidium oocysts (confirmed)	PRT/HSH/TITCH/T-IPA-1.3.1	Failure to operate the treatment works in accordance with the recommendations of the Badenoch and Boucher reports.
Lead (Hoads Hill reservoirs 1, 2, and 3)	PRT/HSH/RHH1/R-IPA-1.1.28	Lead has previously been identified in the sediment within the reservoirs.
Disinfection – Equipment Failure – Microbiological	PRT/HSH/TITCH/T07.1.1	Failure to operate treatment works in accordance with regulation 26.

3. The Company are required to satisfy the following requirements.

The date given (the ‘date’) is that until/ by which requirements must be maintained/ satisfied, as appropriate.

Requirements

(a) To maintain the following measures for the period specified in each case:

1. Continuous on-line monitoring of aluminium post clarifiers and post rapid gravity filtration. 
   Date: Ongoing for the duration of this notice. 

2. Weekly samples for aluminium from the inlet to Hoads Hill Service Reservoirs 1, 2 and 3. 
   Date: Ongoing for the duration of this notice. 

3. Enhanced zonal monitoring for aluminium in all zones supplied by the Itchen Water Treatment Works (WTW). 
   Date: Ongoing for the duration of this notice. 

4. Maintain an effective procedure for the communication of any pollution events from the upstream Southern Water Limited wastewater treatment plant. 
   Date: Ongoing for the duration of this notice. 

5. Enhanced (continuous) Cryptosporidium monitoring of Itchen treatment works final water. 
   Date: Ongoing for the duration of this notice. 

6. Continuous and representative pH monitoring in the raw and post pH corrected water. 
   Date: Ongoing for the duration of this notice. 

7. Subject the water to sufficient preliminary treatment to prepare it for disinfection, including pH correction, as required. 
   Date: Ongoing for the duration of this notice. 

8. Record the completion of daily, weekly and monthly required operational site maintenance checks. 
   Date: By 28 February 2022, after which, ongoing for the duration of the Notice. 

(b) To review, revise or make operational the following measures, by the dates specified in each case:

1. Complete an investigation into the excessive carryover of aluminium from the treatment processes at Itchen WTW, to understand why this is occurring and the resulting impact. The investigation must include the following: 
   1. Clarification of what the Company define as optimisation of the coagulant dose for the Itchen WTW, stipulating what this means with regards to turbidity, pH and residual aluminium levels; 
   2. The procedure for manual restarts of the dosing system following electrical power failures, including any water quality safeguards, how it is ensured this takes place and how it is evidenced; 
   3. The total aluminium concentration post-clarification, post-rapid gravity filters (RGF) and post ultrafiltration; and
   4. Review of aluminium levels throughout an RGF cycle (pre- and post- washes), to ensure removal of any carry-over from the clarification process. 
      Date: 30 June 2022 

2. Complete a full process hazard review to identify the performance capabilities of the existing processes to treat all aspects of the raw water quality under all conditions and including (but not restricted to) the following elements; 
   1. A review of current asset performance and efficacy against catchment hazards and raw water challenge.
   2. A review of site arrangements in respect of compliance with the recommendations of the Expert Group on Cryptosporidium “Badenoch and Bouchier”. In particular, the arrangements for the return of wash water to the head of the works and RGF flow changes. 
   3. A full review of the disinfection process, chemicals used and the parameters monitored and used to control the process. 
   4. Review compliance with the requirements of regulation 31 throughout the treatment processes. 
   5. A review of site pipework, valving, drainage and sanitary disposal facilities. 
   6. An end-to-end review of operational and maintenance tasks (frequency and appropriateness). 
   7. A review of asset criticality, including single points of failure. 
   8. An assessment of hazard containment and recovery requirements, including run to waste, automated shutdown and alarm facilities.
   9. A full review of all sampling and online monitoring against industry good practice, to ensure sampling locations are correct, frequencies are appropriate and that results are representative
   10. A review of contingency planning for the site. 
   11. Review the GAC regeneration frequency.
   12. A review of the use of all consumable materials (e.g. chemicals, filtration media, membranes and cartridge filters) used on site, which are approved under regulation 31(4)a to ensure the manufacturer’s instructions for use, or the national conditions of use (as applicable) are complied with. 
   13. The general condition and operational lifetime of the treatment assets. 
       Date: 30 June 2022

3. Develop an action plan to address any deficiencies identified in measures (b)1 and (b)2. 
   Date: 30 September 2022 

4. Deliver the action plan, developed under measure (b)3. 
   Date: To be confirmed 

5. Optimise the coagulation and put in place ongoing and regular optimisation through appropriate documented controls. Investigate automated coagulant dose control systems. 
   Date: 31 August 2022 

6. Complete an investigation to ensure the requirements of regulation 26(2)(a) are being delivered, to keep disinfection by products as low as possible. 
   Date: 30 June 2022 

7. Complete an investigation into aluminium levels and deposits (and associated potential risks) within treated water storage and networks supplied by the Itchen WTW. 
   Date for associated network and treated water storage tanks for Shedfield, Nelson and Street End: 31 August 2023 
   Date for associated network and treated water storage tanks for Firdown and West Meon: 31 May 2024 

8. Implement any actions required, following the investigation into aluminium deposits in downstream service reservoirs and networks required under measure (b)7. 
   Date: To be confirmed 

9. Complete a review and update of site documentation, on a risk prioritisation basis. 
   Date: 31 December 2024 

10. Complete; 

1. An internal inspection of the Itchen WTW contact tank. Determine the plug flow efficiency of the contact tank. 
   Date: 31 December 2022 

2. Any required mitigation measures to address any risk identified under measure (b)10 a. 
   Date: To be confirmed 

11. Complete; 

1. An investigation into the condition of the Itchen WTW waste water tanks. 
   Date: 30 June 2022 

2. Any necessary remediation identified under measure (b)11 a. 
   Date: To be confirmed 

12. Complete; 

1. An internal inspection of Hoads Hill reservoirs 1, 2 and 3. 
   Date: 31 October 2022 

2. Any necessary remediation identified under measure (b)12 a. 
   Date: To be confirmed 

13. Complete; 

1. An investigation into the high levels of lead and other metals in Hoads Hill reservoir. 
   Date: 31 October 2022 

2. Any required mitigation measures to address any risk identified under measure (b)13 a. 
   Date: To be confirmed. 

(c) To audit whether the measures have been effective by the following means:

1. Define an audit strategy to monitor the effectiveness of the above measures specified in sections (a) and (b).
   Date: 28 February 2022.
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 Itchen Water Treatment Works, or not to 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:

Provide a progress report annually by 31 January and against the following milestones:

1. Provide a report summarising the outcomes of the aluminium carryover investigation required under (b)1. and the hazard review completed under measure (b)2. Provide the action plan to address any outcomes of risk, including dates for delivery. 
   Date: 31 October 2022 

2. Confirm completion of the action plan required under (b)4. 
   Date: To be confirmed 

3. Confirm the clarification process has been optimised and provide details of this and the ongoing optimisation controls and processes in (b)5. 
   Date: 30 September 2022 

4. Provide the outputs from the disinfection by-products review (measure (b)6). 
   Date: 31 July 2022 

5. Report the findings of the investigations into aluminium levels and deposits in the networks and treated water storage tanks (measure (b)7). Confirm the proposed completion date for (b)8. 
   Date for associated network and treated water storage tanks for Shedfield, Nelson and Street End: 30 September 2023 
   Date for associated network and treated water storage tanks for Firdown and West Meon: 30 June 2024 

6. Confirm completion of any required actions under (b)8. 
   Date: To be confirmed. 

7. Provide a summary of the site documentation review and changes implemented as a result. 
   Date: 31 January 2025 

8. Report the findings from the Itchen contact tank internal inspection and confirm the plug flow efficiency of the contact tank. Confirm the proposed completion date for (b)10 b. 
   Date: 31 January 2023 

9. Confirm completion of (b)10 b. 
   Date: To be confirmed. 

10. Report the findings of the investigation of the condition of the waste water tanks (measure (b) 11 a) and confirm dates for any remediation required. 
    Date: 31 July 2022 

11. Confirm completion of (b) 11 b. 
    Date: To be confirmed. 

12. Report the findings of the inspections of all three Hoads Hill reservoirs (measure (b) 12 a) and confirm dates for any remediation required. 
    Date: 30 November 2022 

13. Confirm completion of (b) 12 b). 
    Date: To be confirmed. 

14. Provide a report on the investigation into the lead and other metals detected in the sediment within the Hoads Hill reservoirs (measure (b) 13 a) and confirm dates for any remediation required. 
    Date: 30 November 2022 

15. Confirm completion of (b) 13 b. 
    Date: To be confirmed. 

16. Submit the strategy for auditing the effectiveness of the measures, as specified in (c)1. 
    Date: 31 March 2022 

17. Submit any revisions of the audit strategy produced under measure (c)2. 
    Date: Within 1 month of a revision 

18. Submit a report in the event that any completed measures of this Notice needs to be altered in any way for any reason. 
    Date: Ongoing for the duration of this notice. 

19. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off. 
    Date: To be confirmed 

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

Nick Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment, Food and Rural Affairs.
01 February 2022
Reference: PRT-2021-00003 (V1)