The U.S. Environmental Protection Agency (EPA) has revised the Hazard Ranking System (HRS) in response to the Superfund Amendments and Reauthorization Act of 1986 (SARA). The HRS is the scoring system EPA uses to assess the relative threat associated with the release or potential release of hazardous substances from a waste site. The HRS score is the primary criterion EPA uses to determine whether a site should be placed on the National Priorities List (NPL). The NPL identifies sites that warrant further investigation to determine if they pose risks to public health or the environment. Sites on the NPL are eligible for long-term 'remedial action' financed under the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA), as amended by SARA. The revised HRS retains the same cutoff score and basic approach as the original HRS, while incorporating SARA requirements as well as improvements identified as necessary by EPA and the public. The revised HRS retains the ground water, surface water, and air pathways drops the direct contact and fire/explosion pathways, and adds a forth pathway, soil exposure.

November 9, 1990.