From Landfill to SRF – Helping Scottish Waste Handlers Remain AT4 Compliant

The Waste (Scotland) Regulations 2012 set out several provisions to help Scotland move toward the objectives and targets outlined in Scotland’s Zero Waste Plan and transition toward a circular economy.
Included in this plan was a ban on biodegradable municipal waste going to landfill from 1st January 2021 which is implemented by amending the Landfill (Scotland) Regulations 2003. The purpose of this ban is to:

• reduce waste landfilled by directing residual waste to alternative treatment
• extract remaining resource value from the residual waste stream
• reduce greenhouse gas emissions from landfilling biodegradable waste

After delaying its intended landfill ban by four years, Scotland has focused its efforts on reducing the environmental impact of biodegradable waste that is destined for landfill via the AT4 test. The Scottish Environment Protection Agency (SEPA) determined that if biodegradable municipal waste (BMW) has undergone a treatment process to the extent that it is no longer biodegradable, it will not be subject to the landfill ban.

What is BMW?

BMW includes biodegradable household waste together with biodegradable waste which is similar to household waste such as, for example, waste from the retail and hospitality sectors. It includes residual ‘black bag’ waste and other mixed municipal wastes collected from households and commercial businesses.

What is the AT4 test?

The AT4 test measures the stability of biodegradable waste and considers whether it will break down further, which could cause additional release of greenhouse gas, odour and leachate. The test in Scotland is expected to be implemented and enforced from 2025 and will mean that biodegradable waste not meeting the AT4 criteria will not be permitted for landfill disposal.

What does this mean for waste handlers?

The changes present several challenges to waste handlers and customers. Already feeling the pinch of increased fuel costs and reduced resource, Scotland’s waste infrastructure is under immense pressure. For waste operators, striking a balance between supporting customers in achieving ESG goals and remaining profitable is key.

By treating BMW to ensure its AT4 compliant, waste handlers are able to avoid landfill ban – thus not limiting their options for disposal. One treatment option available is biotechnology – Advetec was recently subject to an independent review of our XO6 unit, which processes residual waste using accelerated aerobic digestion.

The results have shown a mass reduction in excess of 46%, a moisture reduction of >90% and that the output floc met the Irish AT4 limit of 7mgO2/ds, which means that it will achieve the incoming Scottish AT4 limit for biodegradable waste destined for disposal via landfill. What’s more, the wide sampling and testing completed on the floc demonstrate that it is a good quality SRF, unlocking its value to the circular economy.

For more information about how we can help Scottish waste handlers remain AT4 compliant, get in touch.