The Federal Facility Compliance Act of 1992 (FFCAct) requires the U.S. Department of Energy (DOE) to make a comprehensive national inventory of its mixed wastes (i.e., wastes that contain both a hazardous component that meets the Resource Conservation and Recovery Act (RCRA) definition of hazardous waste and a radioactive component consisting of source, special nuclear, or byproduct material regulated under the Atomic Energy Act (AEA)), and of its mixed waste treatment technologies and facilities. It also requires each DOE facility that stores or generates mixed waste to develop a treatment plan that includes, in part, a schedule for constructing units to treat those wastes that can be treated using existing technologies. Inherent in constructing treatment units for mixed wastes is, of course, permitting. This paper identifies Federal regulatory program requirements that are likely to apply to new DOE mixed waste treatment units. The paper concentrates on showing how RCRA permitting requirements interrelate with the permitting or licensing requirements of such other laws as the Atomic Energy Act, the Clean Water Act, and the Clean Air Act. Documentation needed to support permit applications under these laws are compared with RCRA permit application documentation. National Environmental Policy Act (NEPA) documentation requirements are also addressed, and throughout the paper, suggestions are made for managing the permitting process.