Title page 1

Contents 3

Highlights 2

Letter 5

Background 7

DOE's Cleanup Sites and Mission Areas 7

Laws and Regulations Relevant to DOE's Cleanup Mission 10

Potential Future Land Uses at DOE Sites 12

The Role of Anticipated Future Land Use in the Cleanup Process 13

DOE Developed Land Use Plans and Identified Anticipated Future Land Uses as Part of Site Cleanup 14

Selected Sites Worked with Communities and Stakeholders to Develop Initial Land Use Plans 15

Assumptions About Future Land Use Inform Decisions on Remedy Selection 17

The Remedy Selected During Cleanup Affects How Land Can Be Used After Its Transfer 20

Cleanup Decisions Were Consistent with Initial Land Use Plans at Four Sites but More Stringent at Two Others 22

DOE and Regulators Made Cleanup Decisions Consistent with DOE's Initial Plans at Four Selected Sites 22

DOE and Regulators Established More Stringent Cleanup Levels Than Initially Anticipated for Large Areas of Hanford and Idaho Sites 31

Information on Cost of Cleaning Up Areas at a More Stringent Level Than Initially Anticipated Is Not Available 37

DOE Has Completed or Planned Limited Land Transfers or Leases at Selected Sites 38

Selected Sites Have Completed Limited Land Transfers or Leases to Date 38

DOE Has Announced New Initiatives to Reuse Land at the Sites 41

Some Community Stakeholders Expressed Support for More Land Transfers 43

Concluding Observations 43

Agency Comments 44

Appendix I. Objectives, Scope, and Methodology 46

Appendix II. Information on Transferred or Leased Land at the Department of Energy's Six Sites Selected for GAO's Review, as of August 2026 49

Appendix III. GAO Contact and Staff Acknowledgments 51

Table 1. The Department of Energy's Initial Future Land Use Plans at Six Selected Cleanup Sites 15

Table 2. Information on Transferred or Leased Land at the Department of Energy's (DOE) Six Sites Selected for GAO's Review, as of May 2026 49

Figure 1. Estimated Cleanup Costs and Completion Dates for DOE's 15 Remaining Cleanup Sites, as of April 2026 (dollars in billions) 9

Figure 2. Planned Land Uses, Future Land Uses Assumed for Cleanup Levels, and Transferred Land at the Department of Energy's (DOE) Oak Ridge Site 24

Figure 3. Planned Land Uses, Future Land Uses Assumed for Cleanup Levels, and Leased Land at the Department of Energy's (DOE) Paducah Site 26

Figure 4. Planned Land Uses, Future Land Uses Assumed for Cleanup Levels, and Transferred or Leased Land at the Department of Energy's (DOE) Portsmouth Site 28

Figure 5. Planned Land Uses and Future Land Uses Assumed for Cleanup Levels at the Department of Energy's (DOE) Savannah River Site 30

Figure 6. Planned Land Uses, Future Land Uses Assumed for Cleanup Levels, and Transferred or Leased Land at the Department of Energy's (DOE) Hanford Site 33

Figure 7. Planned Land Uses, Future Land Uses Assumed for Cleanup Level Decisions, and Leased Land at the Department of Energy's (DOE) Idaho Site 36