Superfund is a United States federal government program designed to fund the cleanup of sites contaminated with hazardous substances and pollutants. Sites managed under this program are referred to as “Superfund” sites. It was established as the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). It authorizes federal natural resource agencies, primarily the Environmental Protection Agency (EPA), states and Native American tribes to recover natural resource damages caused by hazardous substances, though most states have and most often use their own versions of CERCLA. CERCLA created the Agency for Toxic Substances and Disease Registry (ATSDR). The EPA may identify parties responsible for hazardous substances releases to the environment (polluters) and either compel them to clean up the sites, or it may undertake the cleanup on its own using the Superfund (a trust fund) and costs recovered from polluters by referring to the U.S. Department of Justice.
Approximately 70% of Superfund cleanup activities historically have been paid for by parties responsible (PRPs) for the cleanup of contamination. The exceptions occur when the responsible party either cannot be found or is unable to pay for the cleanup. Until the mid-1990s, most of the funding came from a tax on the petroleum and chemical industries, reflecting the polluter pays principle, but since 2001, most of the funding for cleanups of hazardous waste sites has come from taxpayers. Despite the name, the program has suffered from under-funding, and Superfund cleanups have decreased to a mere 8 in 2014, out of over 1,200. As a result, the EPA typically negotiates consent orders with PRPs to study sites and develop cleanup alternatives, subject to EPA oversight and approval of all such activities.
The EPA and state agencies use the Hazard Ranking System (HRS) to calculate a site score (ranging from 0 to 100) based on the actual or potential release of hazardous substances from a site. A score of 28.5 places a site on the National Priorities List, eligible for long-term remedial action (i.e., cleanup) under the Superfund program. As of 9 August 2016, there were 1,328 sites listed; an additional 391 had been delisted, and 55 new sites have been proposed.