Section 20.1 of the Illinois Environmental Protection Act instructs the Illinois EPA to identify sites that generate, treat, store or dispose of hazardous wastes and to report the types and quantities of hazardous waste involved. Hazardous waste is defined by the Resource Conservation and Recovery Act (RCRA), which gave the EPA authority to control hazardous wastes from cradle to grave. This publication makes no attempt to analyze this data. Analysis is contained in a companion publication: Hazardous Waste Generation and Management.