1. Anaerobic Digestion of Manure and Slurry
The Regulations
Sharon Chisholm
Senior Environment Officer - Agriculture
2. Recent change in regulatory position
â˘Where the only waste feedstock to AD plant is farm
manure/slurry
â˘the digestate is not waste
â˘provided it is applied to land for agricultural benefit
â˘BUT, the biogas will be waste
3. Regulatory Implications for the AD Plant
AD plants using manures/slurries must hold the
ď¨
appropriate EA authorisation
Most farm AD plants will qualify for exemptions from
ď¨
permitting
They will just need to register simple, free
ď¨
exemptions with the EA
If the feedstock includes food waste or other
ď¨
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 â 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.