Changing premises -- changing policies

The assumption that cleanup is necessary at all leaking UST sites is being questioned. The concept of natural attenuation coupled with natural biological degradation is the basis for challenging the assumed necessity of cleanup. Evidence from numerous studies indicates that natural attenuation and degradation of petroleum occur over time. These studies suggest that the processes of attenuation and degradation occur at all petroleum release sites, to varying degrees, once the actual leak is stopped. Because attenuation and degradation occur, it is asserted that cleanup of petroleum contamination is not necessary if the risk of exposure to the remaining contamination is low. The question of ''how clean is clean?'', based on the assumption that cleanup is necessary at all sites, then changes to ''is cleanup necessary at this site?'' The starting assumption becomes ''cleanup may not be necessary if risk is low.'' Public acceptance of leaving contamination in place appears to be increasing. Common criticisms, such as real estate/property values, prevention incentives, and ground water as resource issues are addressed. Also offered is a suggested framework for future policy decisions focusing on the appropriate amount of information necessary to close a leaksite