The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) was passed by Congress in 1980. It the program it established, better known as the Superfund program, is responsible for managing environmental cleanup of sites of major hazardous waste contamination. The program is overseen by the US Environmental Protection Agency (EPA). When the persons or corporation responsible for the contamination can be identified, they are considered financially liable and must fund the cleanup. CERCLA also established a tax on chemical and petroleum companies to establish a trust fund used to finance cleanups where no responsible party can be identified.
In its 20 years of existence, the Superfund has completed cleanup at 750 sites around the country, and work continues at many more. The largest Superfund site is the Berkeley Pit in Butte, Montana. One of the sites most recently added to the list was the Willamette River in Portland, Oregon.