EPA's Preliminary Estimates of Future Hazardous Waste Cleanup Costs Are Uncertain

In response to a congressional request, GAO evaluated the Environmental Protection Agency's (EPA) Superfund Task Force Preliminary Assessment study on what resources are needed to clean up the worst uncontrolled hazardous waste sites.

The preliminary EPA study reported that 1,400 to 2,200 hazardous waste sites may require cleanup as National Priority List (NPL) sites and that the federal government could spend between $8.4 and $16 billion to clean up the sites. The study provided uncertain data regarding the number of NPL sites, cleanup construction costs, and parties responsible for cleanup. GAO found that: (1) projected Superfund program costs can vary considerably; (2) total cleanup costs include expenses other than Superfund program costs; (3) the timing of cleanups is relevant to annual and future commitment; and (4) in the future, EPA may be able to estimate the reduction of health risks based on levels of cleanup. GAO noted that EPA is currently making more detailed analyses of the sites and associated cleanup costs which could improve future estimates.