The Superfund program (http://www.epa.gov/superfund/index.htm) is part of a federal government effort to clean up land in the United States that has been contaminated by hazardous waste and that has been identified by the Environmental Protection Agency (EPA) (http://www.epa.gov/) as a candidate for cleanup because it poses a risk to human health and/or to the environment.

The program was created in 1980 when Congress enacted the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) (http://www.epa.gov/superfund/action/law/cercla.htm). The US Environmental Protection Agency (EPA) works with communities, "potentially responsible party" (PRPs), scientists, researchers, contractors, and state, local, tribal, and Federal authorities to identify hazardous waste sites, test the conditions of the sites, formulate cleanup plans, and to decontaminate the sites.

Sites where releases or potential releases have been reported are listed in a searchable EPA database called the Comprehensive Environmental Response Compensation and Liability Information System (CERCLIS) (http://www.epa.gov/superfund/sites/cursites/index.htm).

CERCLA was amended by the Superfund Amendments and Reauthorization Act (SARA) (http://www.epa.gov/superfund/action/law/sara.htm) in 1986.

CERCLIS (Comprehensive Environmental Response, Compensation and Liability Information System) (http://www.epa.gov/superfund/sites/cursites/index.htm) is a database maintained by the US Environmental Protection Agency (EPA).

CERCLIS contains information such as the current status of cleanup efforts, cleanup milestones reached, and amounts of liquid and solid media treated at sites on the National Priorities List (NPL) or under consideration for the NPL.

Search the CERCLIS database at http://cfpub.epa.gov/supercpad/cursites/srchsites.cfm.

The substances found at Superfund sites have been designated by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) as 1) causing or contributing to an increase in mortality or in irreversible or incapacitating illness, or 2) posing a substantial present or potential hazard to human health or to the environment when improperly treated, stored, transported, disposed of, or otherwise managed.

More than 800 substances are currently designated as hazardous (http://www.epa.gov/oswer/riskassessment/glossary.htm#h), and many more as potentially hazardous. These substances do not include petroleum or natural gas.

A list of Superfund chemicals found in TOXMAP can be found at http://toxmap.nlm.nih.gov/toxmap/main/sfChemicals.jsp.

The Superfund site cleanup process begins with the reporting of possible releases of hazardous substances by individual citizens, responsible parties or EPA regional offices. The EPA then registers the information in the Comprehensive Environmental Response, Compensation and Liability Information System (CERCLIS), an electronic record of sites affected by potentially hazardous substances.

The EPA examines possible release of hazardous substances from a site via several processes:

• Preliminary Assessment/Site Inspection (PA/SI)- reports the initial/current state of a site
• HRS Scoring- determines if the site should be on the National Priorities List (NPL)
• NPL Site Listing Process- prioritizes the most serious sites
• Remedial Investigation/Feasibility Study (RI/FS)- studies the degree of site contamination
• Record of Decision (ROD)- explains which cleanup alternatives will be used to clean up a Superfund site. The ROD for sites listed on the NPL is created from information generated during the Remedial Investigation/Feasibility Study (RI/FS)
• Remedial Design/Remedial Action (RD/RA)- discusses effective remediation options
• Construction Completion- signals the end of the site cleanup process
• Post Construction Completion - ensures long-term protection for the community and the environment.

The development of Superfund site cleanup plans includes several cleanup options. The EPA regularly invites public comment on the cleanup process in their community. The EPA also encourages citizens to participate in community advisory groups.

• EPA EnviroMapper StoreFront
  EPA EnviroMapper StoreFront (http://www.epa.gov/enviro/html/em/) provides several GIS-based mapping tools. Window to My Environment (http://www.epa.gov/enviro/wme/) and EnviroMapper for Envirofacts (http://www.epa.gov/enviro/emef/) both display Superfund sites along with other locations that report to the EPA.

• US Geological Survey (USGS) National Atlas
  The US Geological Survey (USGS) National Atlas (http://www.nationalatlas.gov/) can map Superfund sites (http://www.nationalatlas.gov/natlas/Natlasstart.asp) and over 400 other kinds of data.

• HUD Enterprise Geographic Information System (EGIS)
  HUD Enterprise Geographic Information System (EGIS) (http://egis.hud.gov/egis/) can map Superfund locations with HUD (Department of Housing and Urban Development) community and housing data.
• Environmental Defense/"Scorecard"
  Environmental Defense, a US non-profit environmental organization (http://www.scorecard.org/), provides a resource for information about pollution problems and toxic chemicals; it includes maps of Superfund sites (http://www.scorecard.org/env-releases/land/community.tcl).

Potentially Responsible Parties (PRPs) of Superfund sites are current or former owners or operators of a facility, transporters of a hazardous substance who chose the site for disposal, or agents who coordinate treatment or disposal of hazardous substances at the site. Identifying the PRPs for clean up of a site is an EPA priority.

Sometimes the PRP is unwilling or unable to assume responsibility, or the PRP cannot be found. In these cases, the EPA, the state, or the tribe will clean the area with funding from the Superfund program. The EPA website on Compliance and Enforcement provides further information on legal responsibility for cleaning dangerous waste sites (http://www.epa.gov/compliance/).

The National Technical Information Service offers a list of PRPs at individual sites (http://www.ntis.gov).

A Superfund site is any land in the United States that has been contaminated by hazardous waste and identified by the Environmental Protection Agency (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) .

The NPL is the list of national priorities among the known releases or threatened releases of hazardous substances, pollutants, or contaminants throughout the United States and its territories. The NPL is intended primarily to guide the EPA in determining which sites warrant further investigation. The site's NPL "status" can provide more information about the site in relationship to the NPL:

• Proposed: Site proposed (by the EPA, the state, or concerned citizens) for addition to the NPL due to contamination by hazardous waste and identified by the Environmental Protection Agency (EPA) as a candidate for cleanup because it poses a risk to human health and/or the environment
• Withdrawn: Site removed from the National Priorities List (NPL) because the EPA has determined that it poses no real or potential threat to human health and the environment
• Final: Site determined to pose a real or potential threat to human health and the environment after completion of Hazard Ranking System (HRS) screening and public solicitation of comments about the proposed site
• Deleted: Site deleted from the National Priorities List (NPL) by the EPA (with state concurrence) because site cleanup goals have been met and no further response is necessary at the site.

The National Priorities List (NPL) contains the most serious uncontrolled or abandoned hazardous waste sites throughout the United States and its territories. The NPL lists sites after 1) completing a Hazard Ranking System (HRS) screening and 2) soliciting and addressing public comments about the proposed site.

The NPL guides the federal government in determining which sites should be investigated. It is updated on a regular basis.

The EPA designates several NPL statuses for Superfund sites: Proposed, Final, Deleted, Withdrawn, and Removed. Other Superfund sites are not on the NPL. TOXMAP contains data only on sites designated as Final (currently on the final NPL), Proposed (proposed for the NPL), and Deleted (deleted from the final NPL). These three statuses are collectively referred to by the EPA as the "NPL Dataset".

For details on the NPL site listing process, see http://www.epa.gov/superfund/sites/npl/npl_hrs.htm.