Simplified Calculation of Ammonia Impact Limits (SCAIL) Project

SEPA has a duty to consider the effects on Special Areas of Conservation (SACs), Special Protection Areas (SPAs), Ramsar sites and Sites of Special Scientific Interest (SSSIs) when processing applications for, and reviews of, environmental licenses. As part of this work, the SCAIL screening tool has been developed by SEPA in co-operation with the Centre for Ecology and Hydrology (CEH), the Scottish Government and the Environment Agency.

Under the Integrated Pollution Prevention and Control (IPPC) Directive, permits are required for pig and poultry systems with more than a certain number of livestock (40000 places for poultry, 2000 fattening pigs or 750 places for breeding sows). SCAIL was developed to provide an estimate of the amount of nitrogen deposited, in form of NH3, on a habitat from the assessed livestock unit, storage area or spreading technique. The estimated deposition value can then be used to assess whether more complex dispersion and deposition modelling is needed to determine if the impact limits for the habitat are exceeded or not.

The SCAIL model is freely available at: www.scail.ceh.ac.uk external link