Technical Note DBPAS12: Categories of Digestate Biofertiliser

The Digestate Biofertiliser Certification Scheme (DBCS) has taken a risk-based approach to the variety of biodegradable organic material available for anaerobic digestion.  The Scheme has developed categories that combine feedstocks together based on their origin and characteristics. These have been adapted from the EU legislation that groups animal by-products depending on their risk of spreading disease (see Appendix 1).  The DBCS feedstock categories are Group A which require pasteurisation at the AD facility and Group B which do not need pasteurisation.

The type of feedstock and processing requirements for Group A and Group B also determines if there are any restrictions on the resulting biofertiliser when it is applied to land.  The sensitivity of the receiving environment and end use for the land also influences any conditions or withholding period that may apply when spreading biofertiliser.

Biosolids from municipal wastewater treatment facilities are a separate class of digestate biofertiliser and require pasteurisation.