What is Nutrient Neutrality?
Pollution caused by too many nutrients, particularly nitrogen and phosphorus, in our rivers and estuaries is a big problem for some locations. The nutrients of concern arise from fertilisers, untreated or partially treated sewage and water running off developments (to name a few sources). Natural England therefore has created the “National Nutrient Mitigation Scheme” to neutralise the introduction of more nutrients from new developments in water catchment areas that are particularly sensitive. These sites are internationally important and are protected under the Conservation of Habitats and Species Regulations 2017.
The scheme was launched in 2023.
What type of developments does Nutrient Neutrality affect?
The scheme applies to new developments in England, within certain catchment areas, where there is a net increase in people staying overnight or where there is clear evidence that people are travelling from outside the water catchment to the new development. Some new agricultural and industrial infrastructure projects in these areas might also be affected.
You can check which areas are affected using “magic map” and following the instructions on the gov.uk web page or by contacting the local authority for the proposed site.
How does Nutrient Neutrality work?
Using the latest catchment calculator, Local Authorities and developers determine the level of mitigation required to cancel out the additional nutrient pollution of the proposed project. They then must demonstrate that they can deliver the project with zero net increase in nutrient levels, hence “Nutrient Neutrality “.
Nutrient Neutrality Mitigation Measures
Mitigation measures for nutrient neutrality include (but are not limited to):
- constructed wetlands
- changes in land management
- Sustainable Urban Drainage Systems (SuDS)
- specialist stormwater treatment devices
- nutrient credits via a nutrient trading scheme.
Ideally the mitigation measures would be on the site of the development, however, there is provision within the Scheme for the measures to be off-site as long as they are within the same water catchment area. This enables other landowners within the catchment area to take action to reduce their nutrient load and trade “nutrient credits” to mitigate nutrients from the new development.
Phosphorus and Nitrogen Treatment Devices for Nutrient Neutrality
3P HydroSystem Filters water before a river or watercourse
The 3P Technik HydroSystem is a multi-process surface water treatment system that can be installed or retrofitted to the drainage network. Installed in either concrete or PE chambers it has a patented filter material within it that removes pollutants including PAH’s, hydrocarbons, heavy metals, ammonium, nitrate and crucially binds phosphorus from stormwater runoff. Phosphorus removal via a HydroSystem provides an extremely useful device with the nutrient neutrality toolbox for new development projects. The multistage four-step treatment train removes both solids and dissolved pollutants. “We can remove 40% of dissolved P with our proven media technology, as well as P bound to particles. Filtration of TSS is 100% removal down to 70 microns”.
Further information
For further information about the 3P HydroSystem please contact us.
Further information about the Nutrient Neutrality Mitigation Scheme go to Natural England or Local.gov.