ADAS Environmental Consultants have been working for the last four years with Scottish Water Waste Services (SWWS) providing on site monitoring as well as consultancy services on environmental emissions at the Deerdykes in-vessel composting site in Scotland.
The ADAS service for both bioaerosol and odour emissions provided a one stop shop for SWWS and resulted in a comprehensive approach to environmental footprint of the site and production of a consistent monitoring regime for the operational permit requirements.
Background
The aerated in-vessel tunnel compost plant was built in 2005 in place of existing sewage treatment facilities located in Cumbernauld in Scotland. The site location between the two large cities of Glasgow and Edinburgh enables processing of different waste types ranging from kerb side collected green waste, to category 3 animal by-products material. The facility is processing up to 45,000 tonnes per annum of waste, and the end product is recycled to land close by the site.
Emissions monitoring
Bioaerosol sampling has been undertaken on an annual basis using single stage Andersen type impact samplers, measuring operation emissions, emissions at nearest receptors, and rate of decline over distance from the site.
Odour sampling was undertaken simultaneously with the bioaerosol work using sample collection equipment to collect the samples which are sent to an accredited odour laboratory for analysis.
The bioaerosol sampling was carried out according to The Composting Association’s (now known as the Association for Organics Recycling - AFOR) Standardised Protocol for the Sampling and Enumeration of Airborne Micro-organisms at Composting Facilities and included the following sampling positions:
- on site: from the reception hall, the biofilter, and during the windrow turning and screening.
- off site: at the nearest receptors
- at the site boundary
Conclusions
SWWS received comprehensive reports on both bioaerosol and odour emissions from the ADAS site operations to comply with the site permit requirements of the Scottish Environment Protection Agency and allow continued operation. SWWS have the added benefit of the advice from experienced consultants during the monitoring programme, providing confidence that the site operates with minimal effect on the surrounding environment .
Both boundary and off site measurements showed that bioaerosol emissions were well below Environment Agency guidance limits, and also showed that emissions are effectively managed and reduced significantly by the extraction systems that have been installed on site.
For further information on ADAS bioaerosol and odour services please contact: Charlotte Pearson by telephone 0845 766 0085or e-mail Bioaerosols@adas.co.uk