(1) At closure, the owner or operator shall remove all hazardous waste and hazardous waste residues from the containment system and shall decontaminate or remove all remaining containers, liners, bases and soil containing or contaminated with hazardous waste or hazardous waste residues.(2) Upon removing hazardous waste from the containment system, the owner or operator shall become a generator of hazardous waste and shall manage it in compliance with all applicable requirements of 310 CMR 30.000.