REC was commissioned to undertake Air Quality and Odour Assessments of potential atmospheric emissions from a proposed anaerobic digestion plant and associated biogas engine in Coltishall, Norfolk. This included dispersion modelling using ADMS 4 to predict potential impacts at sensitive locations in the vicinity of the facility.
The Air Quality Assessment considered emissions of a number of potentially harmful substances, including nitrogen dioxide, sulphur dioxide, carbon monoxide and volatile organice compounds (VOCs) from the biogas engine. A sensitivity analysis of different meteorological conditions was included in order to ensure all potential situations were considered and the maximum potential impacts could be identified. The assessment indicated low impacts at sensitive locations and we identified a recommendation for a shorter stack height than originally envisaged. This resulted in cost savings for the client, as well as reducing potential visual impacts associated with the scheme.
The Odour Assessment considered fugitive emissions from a number of site areas, including silage storage and transportation, the feedstock hopper and air expelled from the digestate tanker. Impacts were predicted at a number of sensitive locations in the vicinity of the facility and compared against the criteria provided within Environment Agency Guidance H4: Odour Management. The results of the assessment indicated the operation of the development would not result in odour nuisance at any location.
Following REC’s involvement in the project, planning consent has since been received for the proposals.