310 CMR, § 30.585
Closure shall not be considered complete until all facility equipment, structures, and soil have been properly disposed of or decontaminated by removal of all hazardous wastes and residues. During each closure period, all contaminated equipment, structure, and soils shall be properly disposed of or decontaminated unless otherwise specifically specified in 310 CMR 30.000. In addition, during the closure period of a hazardous waste incinerator, the owner or operator shall remove from the incinerator site all hazardous waste and hazardous waste residues, including, but not limited to, ash, scrubber waters, and scrubber sludges. By removing any hazardous wastes or hazardous constituents during closure, the owner or operator might become a generator of hazardous waste and, if he does, he shall handle that waste in compliance with all applicable provisions of 310 CMR 30.000.
310 CMR, § 30.585