Class A Biosolids Production by a Low‐Cost Conventional Technology

Abstract

Encouraged by a finding that the pathogen analyses of numerous samples of the final product of the Metropolitan Water Reclamation District of Greater Chicago, Illinois (District), met the U. S. Environmental Protection Agency (U. S. EPA) Class A criteria, the District optimized and codified the operation of its sludge processing trains (SPTs), submitted a petition to the U. S. EPA Pathogen Equivalency Committee for obtaining certification of its SPTs as equivalent to a process to further reduce pathogens, and conducted a 3 year full‐scale study. The objective of the study was to determine whether or not the District's SPTs consistently produced a Class A biosolids final product. The primary conclusion drawn from this optimized and codified operation study was that all batches of the final air‐dried product complied with the Class A criteria as specified by U. S. EPA in the Part 503 regulations.