Nutrient neutral development position statement

Position statement on nutrient-neutral requirements for new development

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, 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.

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). 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.

3. It is for the Local Planning Authority and Natural England to determine what nutrient neutrality is, which nutrients this applies to (phosphorus and/or nitrogen), and how this should be calculated and demonstrated.

4. It is for the developer to demonstrate to the Local Planning Authority and Natural England, as part of the planning process, that their development satisfies these requirements.

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 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.

7. If promoters of development sites are considering standalone private treatment arrangements, please be aware that they will require Local Planning Authority, Natural England and Environment Agency approval. Wessex Water 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 as explained here.
Wessex Water have no objections to receiving treated foul effluent from PTPs into our public system for further treatment at our WRCs. Although we do note that, unless adopted, any maintenance and operation liability for the PTP and network upstream of the point of connection to the public sewer 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.

8. 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.

The Wessex Water Group continues to actively work with regulators and Local Authorities, including the promotion of catchment solutions to the issue through a Catchment Market in nature based projects. Wessex Water Group's wholly owned subsidiary, EnTrade, is one provider of these solutions.  However other options are available within these catchments.

Matt Wheeldon
Director of Assets and Compliance
On behalf of Wessex Water
January 2021 (updated July 2021 and October 2021)

Wessex Water Services Ltd (WWSL) is a regulated water supply and sewerage utility company.

EnTrade is a trading name of Wessex Water Enterprises Ltd (WWEL), which undertakes unregulated water and waste water activities. EnTrade, launched in 2017, was developed as a trading platform to facilitate nitrogen offsetting in the Poole Harbour catchment in place of improvements at Dorchester and Wool WRCs, but now creates and operates on-line markets for nature based solutions across the WWSL region and also throughout the country.

Both WWSL and WWEL are subsidiaries of Wessex Water Ltd (referenced in the last paragraph above as Wessex Water Group). Payments to offset regulated activities are ultimately made by WWSL and are fully accounted in our annual reports to Ofwat, our financial regulator, and we use EnTrade as the trading platform for many of these activities. Unregulated activities, such as EnTrade providing services in the Somerset Levels and Moors area to offset developer obligations, are accounted separately. It should be noted that other trading platforms may offer similar services to EnTrade.