Superfund is the common name given to the law called the Comprehensive Environmental Response, Compensation and Liability Act of 1980, or CERCLA. Superfund is also the trust fund set up by Congress to handle emergency and hazardous waste sites needing long-term cleanup. (In this sense, “trust fund” is money government sets aside for a specific purpose. That means that the government can’t spend Superfund money on anything except cleaning up hazardous-waste sites.) Superfund is administered by the Environmental Protection Agency (EPA).
A Superfund site is any land in the United States that has been contaminated by hazardous waste and identified by the EPA as a candidate for cleanup because it poses a risk to human health and/or the environment. These sites are placed on the National Priorities List (NPL).