1. Anaerobic Digestion of Manure and Slurry
The Regulations
Sharon Chisholm
Senior Environment Officer - Agriculture
2. Recent change in regulatory position
•Where the only waste feedstock to AD plant is farm
manure/slurry
•the digestate is not waste
•provided it is applied to land for agricultural benefit
•BUT, the biogas will be waste
3. Regulatory Implications for the AD Plant
AD plants using manures/slurries must hold the
appropriate EA authorisation
Most farm AD plants will qualify for exemptions from
permitting
They will just need to register simple, free
exemptions with the EA
If the feedstock includes food waste or other
materials covered by the Animal By-Products
Regulations, the plant will be subject to those
Regulations. This is not regulated by the EA.
7. Worked example for a large dairy farm digesting
own manure
1 cow - 53 litres excreta, 2.9kg bedding, 18 litres parlour
washings per day
500 cow heard – 37m3 per day
Using an AD plant with 20 day retention time, total manure being
digested at any time will be 740m3
9. Worked example for a large dairy farm digesting
own manure
1m3 cattle manure produces 20m3 of biogas with calorific value
5.83kWh/m3
AD plant will therefore produce 740m3 biogas per day which
produces 180kW (0.18MW) of thermal energy when burned as a
fuel.