Notice of Regulation: Embsay Water Treatment Works – AMP7 Upgrade




Embsay WTW
Embsay / Skipton Water Supply System (YSAI00130848)

Legal Instrument Database Reference number: YKS-2018-00006


  1. has received a report from Yorkshire Water (the “Company”) dated 23rd December, 2017 which states that there is a significant risk of supplying water from Embsay Water Treatment Works that could constitute a potential danger to human health.
  2. GIVES NOTICE to the Company under regulation 28(4) of the Water Supply (Water Quality) Regulations 2016 that it must satisfy the following requirements:

For risks associated with:

  • Manganese
  • Cryptosporidium
  • Bacteria
  • Disinfection by-products
  • Trihalomethanes
  • Halo acetic acids


(a) to maintain the following measure[s] for the period specified [in each case]

Date: For the duration of this Notice

  1. Continue to regularly monitor raw water trends for the parameters manganese and colour, and keep under review dissolved organic carbon (DOC) and turbidity trends from on-line monitoring (UV254)
  2. Regularly review residual manganese and DOC from the existing treatment processes.
  3. Optimise coagulation pH and coagulant dose, and the minimisation of filter turbidity.
  4. Regularly review treatment works performance within Water Quality and Production Operational teams to maintain optimised conditions and maximise the removal of manganese and DOC
  5. Regularly monitor treated, stored and distributed water for manganese and disinfection by-products (THMs and HAAs) and treated water for Cryptosporidium
  6. Continue to review opportunities for catchment management activities with stakeholders to implement protective measures and reduce the risk of deterioration of raw water quality, and implement those measures agreed with the EA as part of the AMP7 WINEP
  7. Continue to keep under review the temporary repairs to the structural defect responsible for the potential Cryptosporidium risk

(b) to review, revise and/or make operational] the following measures, by the date specified below:

  1. Regularly monitor treated water, water within key service reservoirs, and distributed water for manganese and disinfection by-products(THMs and HAAs)
    Date: From 30 April, 2019 for the duration of this notice
  2. Regularly review the level of residual manganese remaining from raw water following the existing processes and ensure its removal is optimised, without compromising the levels of disinfection by-products
    Date: From 30 April, 2019 for the duration of this notice
  3. Carry out further investigations into the technical solution which will provide for improved final water quality, compliance with regulation 4 under all operating conditions and improved operational resilience. Carry out engineering and process reviews and, where required, pilot trials. The technical solution must provide for
    Date: 31st October, 2020
    • a. manganese removal from the raw water from the Nidd Aqueduct and Embsay IRE inlets,
    • b. cryptosporidium and particle removal through the treatment works
    • c. effective disinfection of pathogenic viruses and bacteria in line with company disinfection policy
    • d. structurally sound chlorine contact facilities which can be taken out of supply for cleaning and inspection
    • e. minimisation of disinfection by-products and improved removal of precursors including dissolved organic carbon
    • f. any other relevant parameters to ensure compliance with regulation 4 under all raw water and operating conditions.
  4. Confirm the chosen solution and provide outline design.
    Date: 31st October, 2020
  5. Provide a detailed design of the proposed solution
    Date: 31 July, 2021
  6. Install, commission, and verify through testing, the chosen solution
    Date: 30 September, 2023

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

  1. Define a strategy for auditing the effectiveness of the above measures. To include:
    Date: 31 December, 2019
    • a. Sampling and data analysis for manganese, DBPs (THMs & HAAs) and Cryptosporidium, with a focus on ex-works and distributed water
    • b. Development of an auditable means by which the Company will demonstrate minimisation of manganese and DBP risks at the upgraded works under all raw water conditions, and elimination of Cryptosporidium risk due to structural defect
  2. Implement the audit strategy outlined in (c)1 until revocation of this Notice
    Date: 01 April, 2020

(d) not to supply water for regulation 4(1) purposes from Embsay WTW unless the conditions specified below are satisfied

  1. That all reasonable operational steps have been taken to ensure that water that is not compliant with the requirements of regulations 4 and 26, or that is potentially harmful to consumers, is prevented from entering supply.
    Date: For the duration of this notice

(e) to provide the following information in the time and manner specified below to enable monitoring of progress towards the mitigation of the risk of supplying water that would constitute a potential danger to human health:

  1. Provide a progress report, including details of on-going mitigation, annually by 31 January, and against the following milestones:
    • Completion of investigations, pilot trials and development of outline design
      Date: 31 October, 2020
    • Completion of detailed design of the proposed solution
      Date: 31 July, 2021
    • Completion of Installation and commissioning, of the chosen solution
      Date: 30 September, 2023
  2. Review the risk assessment for Embsay WTW as required by Regulation 27(4) and subsequently submit a revised regulation 28/29 report accompanied by a signed board level declaration.
    Date: 30 October, 2023
  3. Submit a satisfactory completion report
    Date: 30 October, 2024

Failure by the Company to comply with this Notice may result in enforcement proceedings under section 18 of the Act. [Further contravention of the regulation 28(4)(d) or 29(4)(d) requirement in this Notice is an offence and a person guilty of the offence shall be liable on conviction to a fine].

Signed by authority of the Secretary of State
Milo Purcell
Deputy Chief Inspector
1 April 2019
DWI ref: LI/YKS/2018/00006
Version Number: 1

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