Biosolids Thermal Dryer Safety

Since the 1920s, thermal drying produces easily handled, virtually pathogen-free biosolids that promote the beneficial use of nutrients present in wastewater solids. However, thermal-drying systems can be hazardous to operate. Managing this sometimes friable, combustible, and self-heating product can be a delicate task for operators and components of a dryer system can be at risk of fire or explosion.

This safety fact sheet is directed to persons involved with operating, maintaining, and designing biosolids thermal dryers and reviews the fire and explosion safety hazards associated with thermal drying of biosolids and offers both prevention and mitigation measures to address these hazards at water resource recovery facilities. It also summarizes applicable codes and identifies additional resources that may be consulted for further research, education, and remediation.