Position statement on nutrient-neutral requirements for new development

This statement provides an update on our current position with respect to working with developers to provide nutrient neutrality capacity at our water recycling centres.

Wessex Water’s water recycling centres (WRCs) accept additional flows and loads from housing developments as we have planned sufficient capacity for allocated development.

  1. Our WRCs and the environmental permits that govern them are designed to reflect increases in population levels due to development over a 25-year design horizon. A legal case in the Court of Justice of the EU in 2018 (known as the 'Dutch Nitrogen Case'), however, means that measures to mitigate the impact of nutrients in water bodies can no longer be postponed into the future.
  2. Prior to the legal precedent set by the Dutch Nitrogen Case, nutrient neutral development had already been incorporated into planning policy for developments impacting the Hampshire Avon (relating to phosphorus discharges) and Poole Harbour (nitrogen discharges).
  3. Natural England is the government’s adviser for the natural environment and is the arbiter of what is permissible in respect of nutrient neutrality and the obligations arising from the Dutch Nitrogen Case. In particular Natural England determines what nutrient neutrality is, which nutrients this applies to (phosphorus and/or nitrogen), and how this should be calculated and demonstrated.
  4. As part of the planning process developers are required to demonstrate to the Local Planning Authority and Natural England that their development satisfies the requirements for nutrient neutrality. Natural England have developed some tools and resources to assist with this, although we note that some councils (including Somerset Council) have support from Natural England for their own nutrient calculators to be used.
  5. Wessex Water has no influence over these requirements through the planning process. We can only accept flows from new developments once planning permission has been granted and the Local Planning Authority and Natural England are satisfied that the relevant nutrient neutrality tests have been achieved.
  6. Wessex Water is already required to meet nutrient reduction targets set by Natural England and the Environment Agency at a number of our WRCs. Our current reduction targets were determined and agreed during the planning stages of our current Asset Management Plan period (AMP7, 2020-2025), subject to legislation and guidance at that time. In addition to asset improvements at WRCs, we are also pursuing Catchment Market opportunities to bolster delivery of our obligations (see penultimate paragraph below). This approach has been agreed with Natural England and the Environment Agency. Detail of current nutrient improvements, timescales and permits is available under the ‘Developers’ tab on our Drainage and Wastewater Management Portal.
  7. Following the Government’s announcement on 20 July 2022, Wessex Water reviewed the implications for future investment and the incorporation of these new requirements into our next Business Plan (AMP8, 2025-2030), alongside other nutrient reductions required to meet other regulatory requirements.

    The Levelling-up and Regeneration Act – which gained royal assent on 26 October 2023 – amended the Water Industry Act to require additional nutrient removal to achieve the Technically Achievable Limit for either phosphorus (0.25mg/l) or nitrogen (10mg/l) at WRCs serving populations of greater than 2,000 within specified areas by 2030.

    The sensitive catchments – as designated on 25 January 2024 – within the Wessex Water region are:
    • Hampshire Avon Special Area of Conservation (SAC) - Phosphorus
    • Somerset Levels and Moors Ramsar - Phosphorus
    • Poole Harbour Special Protection Area (SPA) / Ramsar - Phosphorus and Nitrogen.

    Under provisions within the amended Water Industry Act, water companies can use a catchment permitting approach to achieve the required nutrient load reductions, subject to approval by the Secretary of State. Furthermore, the provisions allow the Secretary of State to consider alternatives to site-based permits – such as catchment nutrient balancing – subject to secondary legislation being put in place.

    Wessex Water submitted proposals to Defra on 31 January 2024, and expect a response by April 2024. At this stage we are unable to offer any further information to developers on this, other than confirm that our proposals provided at least the equivalent nutrient reduction if the specific WRCs had been improved to the technically achievable limit.
  8. Promoters of development sites considering standalone private treatment arrangements, should be aware that they will require Local Planning Authority, Natural England and Environment Agency approval. We will only consider adopting private treatment assets (such as package treatment plants, PTPs) or upstream sewerage networks if they are designed and constructed to adoptable standards.

    In considering options for managing treated foul effluent arising from PTPs, developers are at liberty to seek a sewer connection to our sewerage network for further treatment at our WRCs. Understandably, unless adopted, liability for the continued maintenance and operation of the PTP and network upstream of the point of connection to the public sewer will remain with the developer/owner. There is also no discount for pre-treated domestic sewage, with charges likely established via a bulk sewerage agreement if the PTP serves multiple properties.
  9. Wessex Water has received queries from developers seeking to contribute towards planned phosphorus removal schemes at our WRCs to bring schemes forward, or to fund new schemes at our WRCs where no new (or additional) phosphorus removal is planned. We are actively engaging with Ofwat, our economic regulator, about whether there are changes than can be made to the regulatory framework to facilitate this.
  10. The Government’s announcement in 2022 also advised of a new Nutrient Mitigation Scheme to be administered by Natural England, although this remains in development and to date has limited catchment coverage. We are, however, aware that some councils are developing their own nutrient mitigation schemes and there are a range of existing nutrient offsetting schemes and catchment markets within our region offering temporary and longer-term mitigation solutions for developers.

Toby Willison
Director of Strategy
On behalf of Wessex Water
March 2024

This position statement is periodically reviewed and updated in light of any new or revised regulatory guidance.

Prior versions: January 2021, July 2021, October 2021 and November 2022.

WRC Nutrient Information Portal

Detail of current nutrient improvements, timescales and permits is available under the ‘Developers’ tab.