On May 9, 2025, EPA updated a reference document for requirements related to hazardous waste TSDFs and related information. This “TSDF Toolkit” gathers, in one place, the main publicly available hazardous waste permitting resources so that the permittees, the public, and state permitting authorities (including permit writers) can easily access them. The resources include flow charts of the permitting process, guidance, training modules, Federal Register rulemaking notices, permit appeals, example permits, and links to state and federal resources.