Making Waste AT4 Compliant

Welcome News for Scottish and Irish Waste Producers and Handlers

After a series of independent tests, Advetec’s XO range of aerobic digesters has been confirmed as creating an output compliant with the incoming Scottish AT4 limits. This means that biodegradable waste treated by the Advetec process will remain compliant for landfill disposal.

The AT4 test measures the stability of biodegradable waste and considers will it break down further, which could cause additional release of greenhouse gas, odour and leachate. When biodegradable waste is stable, it will not break down further. This is already a legal requirement within the Republic of Ireland. Waste not meeting the stipulated AT4 level is subject to a higher rate of landfill tax. The AT4 test in Scotland is expected to be implemented and enforced from 2025 and will mean that biodegradable waste not meeting the stipulated AT4 level will not be permitted for landfill disposal.

The recent results from the MSW organic fines processed by the Advetec system indicated that mass reduction was in excess of 46% and moisture reduction was in excess of 90%. In addition, further segregation tests on the <6mm fraction indicated that even this purely organic fraction also met both the Irish and Scottish AT4 limits.

Dr Stephen Wise, Advetec’s Chief Strategic Development Officer said: “These findings demonstrate our evidence-based approach to improving waste management practices and that our process adds tremendous value. If the floc created by our process does have to go to landfill, it will be compliant. For our customers in the Republic of Ireland this means a reduced landfill tax and for our customers in Scotland it means this disposal route will still be available.

“We are however still committed to encourage waste handlers to recover the value of floc in a more sustainable way, such as sending it for processing as a solid recovered fuel (SRF). We’re working with a network of SRF offtakes to ensure there’s the appropriate infrastructure to do this as turning waste into SRF delivers significant savings on gate fees and contributes greatly to the circular economy.”

As the benefits are significant to the current and future waste markets, Advetec has received an influx of enquiries, not only from UK but also repeat orders from the US market.

Stephen added: “We’re investing heavily in R&D and have a comprehensive programme of sampling and analysing in place to unlock the potential of Mixed Residual Waste (MRW) and our technology. Right now, we are undertaking analysis and trials in three key areas. We are looking at the characterisation and quality of MRW, the performance of our machines in terms of mass reduction and moisture content and the composition and subsequent uses of our floc. The more datasets we have the better we can support waste handlers and producers with ongoing MRW innovation.”