This exemption is for anyone who plans on treating food and green waste in a small scale anaerobic digester. With this exemption:

i. you can treat and store up to 50 cubic meters of waste at any one time

ii. waste must retained in the digester for a minimum of 28 days

iii. any resultant biogas must be collected and burnt in an appliance for the purposes of producing energy  (with a net rated thermal input of less that 0.4 megawatts; or an aggregate net rated thermal input of less that 0.4 megawatts where it is used together with other appliances)

Permitted waste streams are listed in tables 1 and 2  on the LoW page. They are the same as those permitted under a T23 exemption – except that there are no extra limitations, in addition to the 50 cubic meters, on the quantity of table 2 waste streams which can be treated.

All projects using an anaerobic digester under a an old paragraph 12 exemption will benefit from a transition period (until 1^st Oct 2011) before they have to apply for and comply with the new exemption.

Unless you enjoy an on-site situation (where food waste is produced on-site, digested on-site and the finished digestate is used on site) you'll need to make sure your anaerobic digester meets the requirements of the Animal By-Product Regulations.

additional info

• Link to EA guidance on T25 exemption (.pdf)
• Link to free online registration for exemptions
• Agricultural or non-agricultural land?