How new nutrients targets may impact on your development

Impact of NRW guidance on Ammonia Assessments

How new NRW Guidance on Ammonia Assessments impacts developments requiring planning permission.

In February 2024 Natural Resources Wales (NRW) published updated guidance on ammonia assessments for emissions to air for developments that require a permit or planning permission.

Aerial ammonia emissions come mainly (>90%) from Agriculture and can adversely affect the environment and have negative impacts on human health. Ammonia is a very reactive gas which can interact with other compounds to form pollutants away from the actual source.

The NRW guidance outlines which type of developments release ammonia, and therefore may need to carry out an ammonia assessment. Developments affected include:

  • Agricultural developments involving an increase in livestock, anaerobic digestion or landspreading.
  • New applications for commercial activities that would require an Ammonia limit in their Environmental permit.

If your planned development is expected to emit ammonia then guidance is provided on how to carry out a screening assessment using a tool called SCAIL, and if necessary, a detailed modelling assessment.

The NRW guidance provides a link to the Air Pollution Information Service (APIS) website which can give you information on the background values of ammonia at your planned development site. This information will be crucial to consider, alongside information on other nearby sources of ammonia, when completing the ammonia assessment process at sensitive sites. A detailed modelling assessment must be carried out where the background value of ammonia is already at or exceeding the levels which cause detriment to species in sensitive sites.

Parts of the Afonydd Cleddau catchment in Pembrokeshire, one of our Special Area of Conservation rivers, has displayed consistent water quality  failures for ammonia as shown in NRW’s compliance report which was released in January 2024. Pembrokeshire County Council (PCC), as a Local Authority, is responsible for upholding the Conservation of Habitats and Species Regulations 2017 through regulation of development within SACs so as not to cause detriment to sites already failing to meet water quality standards. However, NRW has advised that Nutrient Neutrality is not required in relation to ammonia discharges from planned development. This is because tighter ammonia limits are being placed on permitted effluent discharges from public Wastewater Treatment Works (WwTWs) in failing catchments in the Cleddau. Developments may be approved in terms of ammonia impacts where these WwTWs have capacity to accept new connections and still meet their permitted ammonia limits.

The NRW page also provides guidance on what to do if your proposal will reduce ammonia emissions or pollution.