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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.
- 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, however, the Dutch Nitrogen case has meant that this is no longer the case for WRCs which discharge into or upstream of the Somerset Levels and Moors Ramsar site.
- 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). There is the potential that this requirement may be extended to other sites designated under the Habitats or Birds Directives where nutrient levels are demonstrated to be an issue.
- 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 N 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.
- 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.
- 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.
- 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 final paragraph below). This approach has been agreed with Natural England and the Environment Agency.
If we are obligated to make reductions beyond that already planned, we will be advised by Natural England and the Environment Agency, for potential inclusion in our next plan (AMP8, 2025-30), for which initial planning and discussions have already begun. - 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. - 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. This is not possible within our regulatory framework, although we are actively engaging with Ofwat, our financial regulator, about whether changes could be made for AMP8 and beyond. We have also been approached by developer/council-led schemes where land downstream of effluent outfalls of affected WRCs is within the developer’s/council’s control.
There may be potential in these instances for wetland creation to offset phosphorus requirements from the proposed development. We are working through some scenarios, including the wide and differing implications of whether the wetlands is fed directly with treated effluent from the WRC or from the stream/river itself. We have sought advice from Ofwat on charging for final effluent provision to supply developer-led constructed wetlands for offsetting purposes. More details of these charges will be incorporated within our charging policy from April 2023 and subject to annual review. - Following the Government’s announcement on 20 July 2022, Wessex Water is reviewing the implications for future investment and the incorporation of these new requirements into our PR24 Business Plan. As such, we are awaiting further guidance from our regulators: Environment Agency, Natural England and Ofwat, on the phasing, extent and incorporation of this new requirement.
Defra’s announcement indicates that additional nutrient removal to achieve the Technically Achievable Limit for either phosphorus (0.25mg/l) or nitrogen (10mg/l) will be required at WRCs serving populations of greater than 2,000 within specified areas by 2030. The individual WRCs and timing are yet to be confirmed but would commence from 2025, as part of the Levelling Up and Regeneration Bill (to be laid before Parliament in Autumn 2022). At this stage we are unable to offer any further information to developers on this. Detail of current nutrient improvements, timescales and permits is available under the ‘Developers’ tab on our Drainage and Wastewater Management Portal.
Defra's announcement also advised of a new Nutrient Mitigation Scheme to be administered by Natural England. Similarly, the implications of this are yet to be defined and we are aware of a range of existing nutrient offsetting schemes and catchment markets within our region offering temporary and longer-term mitigation solutions for developers. - Wessex Water has responded positively to requests from the Environment Minister, Rebecca Pow, on engagement with developers and LPAs, and the further provision of nutrient reduction in impacted areas.
Our response set out a number of potential opportunities where subject to regulatory clarification and guidance we could potentially provide additional nutrient neutrality capacity that may satisfy Natural England’s requirements and lead to the release of additional housing capacity.
We are pursuing a response to our proposals and our request for regulatory guidance from the relevant authorities.
Matt Wheeldon
Director of Assets and Compliance
On behalf of Wessex Water
January 2021 (updated 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.