Methods to Set Soil Cleanup Goals to Protect Surface and Ground Water Quality at Hazardous Waste Sites

Hazardous waste management programs in the U.S. have focused on the cleanup of sites so that environmental standards are met and environmental and human health risks will be mitigated. The programs involve the cleanup of abandoned sites as well as existing industrial facilities. In many cases the criteria for cleanup at these sites are based on the protection of ground or surface water resources. Criteria can be based on 1) background levels in the surrounding environment, 2) national or state standards set to protect surface and ground water uses, and/or 3) site-specific standards based on risk assessment techniques. Methodologies for the derivation of cleanup goals in the U.S. vary between regulatory programs. Media-protection standards or trigger levels are the simplest to manage, but their appeal can be diminished if they lead to unnecessary cleanup activities. Such simple systems also fail to deal with any unique site characteristics or exposure patterns. Partly in response to such concerns, some U.S. programs depend upon risk assessment to set site-specific cleanup goals. This paper provides several case studies where various approaches to developing cleanup goals have been applied, and discusses the advantages and disadvantages of the different approaches.