In September 2025, Dundee’s Riverside Recycling Centre experienced a fire in its green waste composting facility that burned for seven days before firefighters were able to declare it fully extinguished.
Seven days. Not because crews lacked determination, but because fires in composting sites are unlike almost any other. They smoulder deep inside, resist surface extinguishing, and often reignite. The Riverside fire forced the closure of one of the city’s busiest household waste centres for weeks, disrupting residents and generating a significant environmental burden.
Composting facilities process “green waste”: garden trimmings, grass cuttings, hedge clippings, and similar biodegradable material. To turn this into usable compost, the waste is piled into long heaps called windrows, where microbial activity naturally heats the material to 60 °C or more.
When managed correctly, this process is safe and effective. However, if windrows are built too large, insufficiently aerated, or allowed to dry out, the heat can concentrate and lead to self-heating ignition. In addition, contamination by items such as lithium batteries, aerosol cans, or discarded barbecue coals can introduce additional ignition risks.
Unlike a fire in ordinary refuse, a compost fire does not burn brightly on the surface. It smoulders inside the heap, invisible until smoke begins to escape. Even then, spraying water on the outside is ineffective — the core remains hot. Firefighters must dismantle the windrows with heavy machinery, soak the material thoroughly, and monitor the site for days to prevent re-ignition.
The prolonged fire at Riverside carried consequences beyond the immediate disruption of waste services:
Air quality: Compost fires emit fine particulate matter (PM2.5/PM10) that can aggravate respiratory conditions such as asthma.
Gas emissions: Carbon monoxide, ammonia, and volatile organic compounds are produced, posing additional health risks.
Odour: The smell of decomposing green waste combined with smoke can travel significant distances, leading to public complaints.
Water pollution: The large volumes of contaminated water used to fight the fire can infiltrate drains and watercourses, requiring strict control and monitoring.
For council managers and regulators, these are not abstract risks: they translate into real costs, reputational damage, and regulatory scrutiny.
While no system can completely eliminate risk, the likelihood of such incidents can be greatly reduced through structured management and compliance with best practice. At a minimum, this requires:
Keeping windrows within size and height limits to prevent dangerous heat build-up.
Monitoring temperatures regularly and documenting readings.
Turning windrows on a defined schedule to release heat and maintain safe conditions.
Ensuring adequate moisture levels to prevent overheating.
Screening incoming waste to remove high-risk contaminants such as batteries and pressurised containers.
Maintaining effective fire prevention plans, including on-site water supplies, staff training, and liaison with local fire services.
These are not optional extras: they are recognised elements of environmental best practice and are reinforced in standards such as ISO 14001 Environmental Management Systems.
To support councils and site operators in embedding these practices, SQMC has developed a Green Waste Fire Prevention Readiness Checklist. This simple, tick-box document is designed for daily use at composting sites. It covers windrow management, monitoring, emergency preparedness, and environmental safeguards.
By making the checklist part of routine operations, councils can demonstrate diligence to regulators, reassure communities, and most importantly, reduce the likelihood of another protracted fire incident.
Free Download: Green Waste Fire Prevention Checklist
At SQMC, we believe incidents such as Riverside’s seven-day fire underline the critical importance of structured environmental management. Our role is to provide not only training and certification expertise, but also practical tools that make good practice real on the ground.
The checklist is freely available for download. Our hope is that it becomes a visible, daily reminder of risk control — and that when councils decide they require external training or guidance, they will recognise SQMC as the trusted partner already present on their walls and in their processes.