SCAIL User-Guide Updated

Simple Calculation of Atmospheric Impact Limits from Agricultural Sources (SCAIL-Agriculture) is an important screening tool that can be used to assess impacts to human health and environmental designations from agricultural sources. With increased focus on reducing agricultural ammonia emissions in the UK Government’s 2019 Clean Air Strategy, there is an increasing requirement for agricultural developments to undergo SCAIL Assessments to secure planning permission. SCAIL acts as a screening stage, with the results allowing regulatory authorities to determine if further consideration of ammonia impacts needs to be undertaken.

In March 2024, the SCAIL model and user-guide was updated. Within the update, the background pollution data from APIS has been revised, regional wind statistics from 109 meteorological stations considered, and a new Hybrid mode provided. This update allows further flexibility in undertaking SCAIL Assessments, and allows screening to be completed with the most up to date pollution data available.

What are SCAIL Assessments?

Ammonia emissions occur across agricultural stages and activities. These principally include: housing, storing and spreading stages, which emissions arising from the decomposition and volatilisation of animal wastes. Increases in the concentration of ammonia in the atmosphere, and subsequent deposition to vegetation surfaces can result in:

• Direct damage to vegetation, and acute toxicity in sensitive plants
• Damage or loss of sensitive lichens and bryophytes
• Changes in species composition, with a shift to higher plant species with higher nitrogen tolerances, resulting in reduced species richness
• Acidification of soils and changes to soil nutrient status

The scale of impacts from agricultural activities depends upon a number of variables, including a sites location, meteorological factors, and agricultural techniques used, with impacts having the potential to cause changes in pollution levels at ecological designations. Therefore, many local authorities require a SCAIL Assessment be undertaken and submitted alongside agricultural development plans with the purpose to quantify ammonia concentrations, nitrogen, and acid deposition rates at sensitive locations. This information allows Natural England to be able to evaluate potential effects of a development, meaning SCAIL is a valuable screening tool that can help towards securing planning permission.

Can Redmore Environmental Help You?

Redmore Environmental has over 50 years’ combined experience in the air quality industry, with experience in assessing emissions from a wide range of agricultural development types such as livestock houses, manure stores and slurry lagoons. This has often included undertaking SCAIL Assessments, as well as detailed Ammonia Assessments, to screen potential ammonia impacts from a development.

If you have a requirement for a SCAIL Assessment, please do not hesitate to get in touch with our specialist team today to find out how we can help you.