Anaerobic Digestion of Manure and Slurry

The Regulations

Sharon Chisholm

Senior Environment Officer - Agriculture

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

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.

Will you require a permit or exemption?

Regulatory implications for the use of digestate

No waste regulatory controls

Remember NVZ rules will apply

Regulatory implications for the use of digestate

Waste regulatory controls apply

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

Conclusion: Qualifies for exemption

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.

Conclusion: Qualifies for exemption

Future changes

•DEFRA review of exemptions

•Quality protocol for the use of digestate in 2009

Thank you for listening!

Any Questions?

Sharon Chisholm

01743 283539

www.environment-agency.gov.uk

08708 506 506