Nutrient Neutrality

England is being faced with an ever-increasing issue surrounding residential development and its intrinsic impact on the environment; especially that of protected sites or Sites of Special Scientific Interest (SSSIs). Increased levels of nitrogen and phosphorus lead to the accelerated growth of certain plants which then alters the delicate balance of the microbiome; this is known as “eutrophication”. To mitigate this risk, Natural England (NE) has advised that Local Planning Authorities (LPAs) can only approve development if they are certain that it will not have an adverse effect or cause additional pollution to any “Habitat Sites” which are protected under the Habitats Regulations 2017. This is known as “nutrient neutrality” and has proved to be rather contentious for property developers.

Different LPAs are affected to different degrees; some will have only a small part of their area affected whereas there are other areas that will be impacted to a much greater extent. The extent and scope of nutrient neutrality is partially affected by how unfavourable and likely the site is to be polluted.

Nutrient neutrality is achieved when the nutrient load created through additional (polluted) wastewater (including surface water) from the development is mitigated by using suitable mitigation measures.

Despite the very well-meaning nature of this new policy, LPAs are finding it increasingly more difficult to navigate planning permission and development. Due to the different variables involved that may require some areas to have mitigation and others to not, ‘blanket’ solutions are becoming different to create and commonly require years of planning and thought. Therefore, each specific issue requires its own specific response.

Locally speaking, Norfolk, according to the Norfolk Environmental Credits, is one of the “worst affected areas in the country” as it is being met with the need to address both phosphorus and nitrogen mitigation. By consequence of this, a “planning backlog” has accrued which has meant that developers have had to place their developments on hold. This backlog has been compounded due to the House of Lords vote on 13th September 2023 which meant that the government’s proposals to provide certainty for local authorities, communities, and developers and ‘unblock’ all of the housing that was held up due to nutrient neutrality was rejected.

The effects of the above can be seen in a key case study that Norfolk has recently seen in Weston Homes’ multi-million pound development project of Anglia Square that was recently scrapped at the last minute. Weston Homes cited various causes for this, but they did explicitly state nutrient neutrality as being a key factor: “…in March 2022 further delays to the scheme arose when a Nutrient Neutrality directive from Natural England blocked the building of new homes across Norfolk as it was believed housebuilding could dangerously increase nutrient levels in local wetland and waterways and harm species.”. It is clear that the road to nutrient neutrality has been paved with good intentions, but the execution of such a grand scheme has caused huge consequences for the community and developers alike. As an interim solution, the Planning Advisory Service (PAS) are trying to provide support by creating spaces for LPAs to come together to discuss how this issue is affecting them and to try and assist developers with suitable mitigation measures, however, this appears to be a mere plaster on the cracks being caused by nutrient neutrality.