This action seeks to make regulatory amendments and various updates and clarifications to the Resource Conservation and Recovery Act subtitle C hazardous waste treatment, storage, and disposal and permitting standards. Additional revisions that would impact permitting, for example, changes to definitions or references, may also be proposed for other RCRA regulatory sections. The proposed changes would codify established policies, reflect current information or standards, improve understanding and compliance with the regulations, and make technical corrections and other conforming changes to address inadvertent errors and remove obsolete references. This action also may solicit public input on topics related to RCRA permitting to inform possible future agency actions.