Summary: GAO discussed the Department of Defense's (DOD) compliance with environmental protection laws through its hazardous waste generation, storage, and disposal management, and disposal site cleanup efforts. GAO found that: (1) although it had previously cited storage and disposal problems at 12 installations, delayed disposal, slow construction of storage facilities, and limited hazardous waste reduction still existed; (2) the DOD Guam installations did not comply with the regulations because of their inability to dispose of waste; (3) although it provided a siting of a waste storage facility at Kelly Air Force Base (AFB), public hearings on environmental safety delayed the final permit; and (4) Tinker AFB initiated actions to reduce its waste generation and instituted preventive disposal controls. GAO also found that: (1) DOD created a program to identify hazardous waste disposal sites, assess their potential for contaminating the environment, and take appropriate corrective actions; (2) 6 of the 18 installations reviewed had problems which earlier regulatory involvement could have minimized; and (3) most regulatory agencies still had limited involvement in the program. In addition, GAO found that: (1) during a toxic oil spill at the Guam naval installation, the Navy did not provide personnel with adequate protective equipment, medical monitoring, hazardous substance handling and response, or storage facilities with curbs to prevent spill runoff; and (2) although the Air Force has begun cleanup efforts of groundwater contamination around its plant, regulatory agencies' failure to initiate timely investigative actions has caused a delay in cleanup of the total site.