Current improvement programmes

Notice of Regulation: Teesdale Supply System

NOTICE UNDER REGULATION 28(4) OF THE WATER SUPPLY (WATER QUALITY) REGULATIONS 2016 (AS AMENDED)

NORTHUMBRIAN WATER LIMITED: TEESDALE SUPPLY SYSTEM DISCOLOURATION

Reference: NNE-2018-00002

Water undertaker as appointed under section 6 of the Water Industry Act 1991 (as amended): Northumbrian Water Limited, with registered number 02366703 (hereinafter called ‘the Company’).

Assets affected:
Lartington WTW (T0005166)

System Zone 14 Teesdale incorporating water quality zone T201

  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 15 October 2018 which states that there is or has been a significant risk of supplying water from Lartington WTW (and associated assets as applicable) into System Zone (SZ) 14 Teesdale that 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:
  • Iron
  • Manganese
  • Consumer acceptability – Discolouration brown / orange / black.

  1. The Company are required to satisfy the following:

Requirements

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

  1. Improved reservoir and catchment Ongoing management strategies to reduce metals loadings into the treatment works.
    Date: Ongoing for the duration of the Notice.
  2. WTW optimisation against internal targets for manganese and iron (plus aluminium and turbidity).
    Date: Ongoing for the duration of the Notice.
  3. Final waters optimised for pH to ensure waters are non-corrosive to cast iron mains.
    Date: Ongoing for the duration of the Notice.
  4. Pipeline management applied to current strategic mains assets based on PODDS research.
    Date: Ongoing for the duration of the Notice.
  5. Ongoing uni-directional flushing of district metered areas prioritised based on customer contacts.
    Date: Ongoing for the duration of the Notice.
  6. Training of field operatives to facilitate more effective network operation and management and minimise disruption to customer supplies through the Company’s own activities.
    Date: Ongoing for the duration of the Notice.
  7. Adequate risk assessment planning, with appropriate sign-off, before completion of any planned work in order to consider and reduce the risk of customer impact.
    Date: Ongoing for the duration of the Notice.
  8. Company to install, trial and evaluate the effectiveness of water quality sensors in the Tees strategic Network.
    Date: By 2021 and 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. Land purchase, investigation and design updates.
    Date: 30 June 2022
  2. Complete Phase 1 of the works including:
    Date: 31 December 2025
    • Lay 12 km of single 800 mm main between Lartington WTW and Whorley SR.
  3. Complete Phase 2 of the works including:
    Date: 31 December 2028
    • Lay 25 km of single 800 mm main between Whorley SR and Longnewton SR.
    • Cross connections into C60/60a for Darlington

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

  1. Define an audit strategy for the measures listed in sections (a) and (b) above. This will include as a minimum:
    Date: 31 December 2021
    • Demonstration of the effectiveness of any interim controls to secure compliance, to include evidence of treatment works operation and performance, and DMA flushing activities.
    • Quality control evidence from contractor delivering solution.
    • Commissioning plan for tie-in of new main to the existing strategic network including coordination planning approach, disinfection regimes and sampling to demonstrate cleanliness of operation.
    • Use of analytics to understand the benefits of the new main in terms of discolouration contact rates across Tees zones before and after intervention. This will include the impact on metals reseeding rates in DMAs downstream of the new main.
  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 Teesdale Supply System, 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 by 31 January and against the following milestones:
    Date: Annually by 31 January
    • Summary of Lartington WTW metals performance.
      Date: Annually by 31 January
    • Discolouration contact rates in SZ14 Teesdale including any zonal and district metered area trends or hot spots.
      Date: Annually by 31 January
    • Details of uni-directional flushing activities in SZ14 Teesdale.
      Date: Annually by 31 January
    • Provide a report confirming completion of land purchase, investigations and outline design in relation to the new 37km Tees main and provide a report on any identified risks to the programme around delivery.
      Date: 31 July 2022
    • Confirm commissioning and completion of phase 1 works, as required in measure (b)2.
      Date: 31 January 2026
    • Confirm commissioning and completion of Phase 2 works, as required in measure (b)3.
      Date: 31 January 2029
  2. Review the risk assessment for SZ14 Teesdale Supply System as required by regulation 27(4) and subsequently submit a revised regulation 28 report accompanied by a signed board level declaration.
    Date: 28 February 2029
  3. Submit a satisfactory completion report
    Date: 31 January 2030

  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
Nick Adjei
Deputy Chief Inspector, on behalf of the Secretary of State for Environment,
Food and Rural Affairs
11 October 2021
Reference: NNE-2018-00002
Version 2