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Anglian Water Services Limited – Marham WTW Nitrate, Ion Exchange Treatment 

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

Reference: ANH-2023-00008

Version Number: 2

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:

  • West Norfolk- Marham/ Bexwell Supply System (Ryston (Bexwell) and Marham WTWs) SSC-001-WNM 

Asset Name

Reference

Marham River Nar/ Marham In take 

CNAR CB 

Marham Source  

CMAR0WV 

Marham Source Bore 2 

AMAR2CV 

Marham Source Bore 3 

AMAR3CV 

Marham Source Bore 5 

AMAR5CV 

Marham Source Bore 6 

AMAR6CV 

Marham Source Bore 8 

AMAR8CV 

Marham Source Bore 9 

AMAR9CV 

Marham Source Bore 10 

AMAR10CV 

Marham WTW 

TMAR 

Wisbech PWSZ 

ZFE48 

Marham PWSZ 

ZFE64 

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 31 March 2023 which states that there is or has been a significant risk of supplying water from Marham 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

Increasing nitrate to PCV breach  

Nitrate 

A012 

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.
  1. 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. Regular review and update of groundwater risk assessments. 
    Date: Ongoing for the duration of this Notice
  2. Nitrate exceedance prediction graphs will be regularly updated and nitrate will be assessed as a hazard as part of the Regulation 27 risk assessment for the supply system supplied by Marham WTW, according to a Drinking Water Safety Planning approach. 
    Date: Ongoing for the duration of this Notice
  3. The existing blending option of the higher nitrate sources with the lower nitrate sources at Marham WTW will be optimised to ensure compliance, until the completion of the additional control measures. 
    Date: Ongoing for the duration of this Notice
  4. Operational and regulatory monitoring for nitrate at the raw water and final water at Marham WTW and in the downstream Public Water Supply Zones. 
    Date: Ongoing for the duration of this Notice  
  5. Exceedances investigated in line with company 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:

  1. Implement an enhanced monitoring strategy for nitrate to include the monitoring of all high-risk water sources and associated final water on a weekly basis to supplement the current regulatory treated water monitoring. 
    Date: Ongoing for the duration of this Notice
  2. Report all exceedances of the nitrate parameter to the Local Authority and Health Protection team and agree further additional steps to protect public health as appropriate. 
    Date: Ongoing for the duration of this Notice
  3. Report all regulatory exceedances of the standards for the nitrate parameter to DWI as part of the current monthly exception reporting process. 
    Date: Ongoing for the duration of this Notice
  4. Continue to review the nitrate exceedance prediction graphs. 
    Date: Ongoing for the duration of this Notice
  5. Support any voluntary initiatives to influence nitrate usage in the groundwater catchments upstream of Marham catchment, taking a risk-based approach.  In particular engage with and provide data to the Environment Agency and other relevant stakeholders as required on a regular basis. 
    Date: Ongoing for the duration of this Notice
  6. Continually appraise the risk of nitrate as a hazard as part of the Regulation 27 risk assessment for the supply systems supplied by Marham WTW according to a Drinking Water Safety Planning approach, and ensure that Regulation 28 documents are regularly reviewed and updates provided as necessary.
    Date: Ongoing for the duration of this Notice
  7. Complete planning, design and procurement arrangements to provide Ian ion exchange plant at Marham WTW. 
    Date: 31 December 2026
  8. Complete the construction, installation and commissioning of an ion exchange plant at Marham WTW, designed under measure (b)7. Commissioning must include the following to account for the changes made:
  • An appropriate maintenance regime for any installed processes;
  • Full integration of the new (or modified) processes into the site control and monitoring systems.
  • Updating of the Site-Specific Disinfection Policy and any associated site-specific procedures;
  • Updating of the Site Operating Manual and removal of all out-of-date material from circulation; and
  • Provisions of adequate training for all relevant personnel on the operation, repair and maintenance of the installed (or modified) process and the revised procedures, policies and manual.


Date: 31 December 2028

(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 2024
  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 Marham WTW, 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. A statement to confirm completion of the planning, design and procurement arrangements of ion exchange plant at Marham WTW.
    Date: 31 January 2027
  3. A statement to confirm completion of construction, installation and commissioning of an Ion Exchange plant at Marham WTW.
    Date: 31 January 2029
  4. Review the risk assessment for Marham WTW as required by Regulation 27(4).
    Date: 31 January 2029
  5. Submit the audit strategy for auditing the effectiveness of the measures, as specified in measure (c)1.
    Date: 30 April 2024
  6. Submit any revisions of the audit strategy produced under measure (c)2.
    Date: Within 1 month of a revision
  7. 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
  8. Submit a satisfactory completion report accompanied by a revised regulation 28(1) report with Board level Director sign-off.
    Date: 31 January 2030

Further Details of this Notice:

  1. Any product or substance used as a result of the requirements in this Notice must comply with regulation 31.
  2. 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.
  3. 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
24 January 2024
Reference: ANH-2023-00008

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