The Scottish Environmental Protection Agency (Sepa) has proposed stricter contamination limits for outputs from anaerobic digestion (AD) plants that are to be used as fertilisers.
The agency is consulting on its latest regulatory positions, which also cover food waste and composting, until 29 June.
It proposes that if a digestate or compost complies with PAS110 or PAS100 legislation and Sepa’s stricter contamination limits, it may be spread on land without waste management regulatory control.
Current limits will remain in accordance with the PAS guidance for both materials until April 2017.
After this point, digestate will only be allowed to contain 50% of the previous out-throw limit in PAS110, dropping to 25% in April 2018 and 8% the year after.
From next April, compost will be allowed to contain 66% of the previous out-throw limit in PAS100, falling to 50% the year after.
Sepa has also proposed guidance on food waste management, laying out its expectations of producers, collectors and recyclers.
Food waste managed only in accordance with this guidance will fulfil the waste acceptance criteria at treatment facilities regulated by Sepa in Scotland.
The agency said it also intends to include standard permit conditions in all food waste treatment facility permits to support the guidance.
The AD and bioresources association (ADBA) chief executive Charlotte Morton said: “In many cases food waste AD operators are already going beyond PAS110 requirements to produce high quality digestate products for agricultural markets.
“ADBA will be working closely with Sepa and our operator members to ensure that proposals for tighter restrictions are proportionate and workable.
“Recycling digestate to land replaces carbon-intensive artificial fertilisers, increases our food security and provides farmers with an excellent source of nutrients. This nascent market is a crucial part of the circular economy, and it is important that it is well supported by policy and regulation.”
Food businesses in Scottish towns that generate more than 5kg of food waste a week are now required by law to have it collected separately for recycling, after changes that came into force on 1 January.
In February Scotland’s former environment secretary Richard Lochhead pledged to cut the country’s food waste by a third by 2025, as part of its circular economy strategy.