National Priorities List

Environmental Protection Agency (EPA) regulations outline a formal process for assessing hazardous waste sites and placing them on the NPL.

The NPL is intended primarily to guide EPA in determining which sites are so contaminated as to warrant further investigation and significant cleanup.

[1] The Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), also known as "Superfund", requires that the criteria provided by the Hazard Ranking System (HRS) be used to make a list of national priorities of the known releases or threatened releases of hazardous substances, pollutants, or contaminants in the United States.

EPA will first enter the potentially contaminated facility into a database known as the Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS).

EPA then uses the HRS to review any available data on the site to determine whether its environmental or health risks are enough to qualify the facility for a Superfund NPL cleanup.

[4] TOXMAP was a geographic information system (GIS) application from the Division of Specialized Information Services of the United States National Library of Medicine (NLM) that used maps of the United States to help users visually explore data from the EPA Superfund Basic Research Program and the Toxics Release Inventory.