The Bureau is producing guidance documents, called BREFs, on BAT controls for industrial sectors regulated under the IPPC Directive.
The new draft BREF says there are some 400 slaughterhouses in the UK. The main impacts identified are effluent, for instance from blood, which has a high chemical oxygen demand. Excessive use of water is also a major issue since this adds to the burden on effluent treatment plants.
The Bureau says that discharge levels associated with the use of BAT are 25-125mg/l for COD, 10-40mg/l for BOD and 5-60mg/l for suspended solids. These can be achieved using techniques such as biological treatment.
The Bureau did not reach a conclusion on whether effluent was better treated on site or at a sewage works. The Environment Agency may well require operators which discharge to sewer to consider whether on-site treatment.