National Priorities List

The National Priorities List, or NPL, is a list compiled by the Environmental Protection Agency (EPA) as a part of the Superfund program under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). CERCLA was enacted by Congress on December 11, 1980. This law levied a tax on the chemical and petroleum industries and gave the Federal government broad authority to respond directly to actual or threatened releases of hazardous substances. $1.6 billion was collected in the five years between 1980 and 1985. The tax money was placed in a trust fund for cleaning up abandoned or uncontrolled hazardous waste sites. CERCLA was amended by the Superfund Amendments and Reauthorization Act (SARA) on October 17, 1986.

CERCLA requires the EPA to identify hazardous waste sites on an annual basis throughout the United States. The law allows for two types of response: short-term removal of hazardous materials in emergency situations; and long-term remedial response actions. Long-term response actions can be conducted only at sites placed on the National Priorities List (NPL) by the EPA.

After in-depth testing and studies, the EPA places sites on the NPL in order of severity of contamination. Contamination is measured by the Hazard Ranking System (HRS), which yields a numerical score calculated on the basis of the site's risk factors. Risk factors are grouped into three categories: the site's potential for releasing hazardous substances into the environment ; the amount and toxicity of the waste materials; and the number of people or sensitive environments affected by the hazardous materials. The HRS evaluates four possible pathways of contamination: ground water; surface water; soil exposure; and air migration .

HRS scores range between 0 and 100. Sites that score above 28.5 qualify for listing on the NPL. A site may also be listed if the Agency for Toxic Substances and Disease Registry (ATSDR) issues a health advisory for the site. In addition, each state or territory of the United States is allowed to place one top-priority site on the NPL without regard to its HRS score. The proposal is then published in the Federal Register . At this point, the public has an opportunity to comment in writing on the site's addition to the National Priorities List. As of May 29, 2002, 812 sites on the NPL were classified as having construction completed; 1221 sites remained on the NPL, with 74 new sites proposed for addition to the list.

The EPA administers the Superfund program in cooperation with individual states and Native American tribal governments. The Office of Emergency and Remedial Response (OERR) oversees management of the program.

See also Hazardous waste site remediation; Hazardous waste siting; Superfund Amendments and Reauthorization Act

[Rebecca J. Frey Ph.D. ]

RESOURCES

BOOKS

Probst, Katherine N., and David M. Konisky. Superfunds Future: What Will It Cost? Baltimore: Johns Hopkins University Press, 2001.

OTHER

United States Environmental Protection Agency. Fact Sheets. [cited July 2002]. <http://www.epa.gov/superfund/action/index.htm>.

ORGANIZATIONS

EPA primary contact: Carolyn Offutt, 1200 Pennsylvania Avenue, NW, Mail Code 5202G, Washington, DC USA 20460 (703) 603-8797, Email: [email protected], <http://www.epa.gov/superfund/contacts/index.htm>