The Cleanup of Chemical Waste Sites — A Rational Approach

A conceptual hazard assessment design is presented here for addressing waste site cleanup. Three main steps to be carried out in an evaluation of any potential waste site include, identification of potential chemical exposure, assessment of that exposure in relation to established ‘safe’ concentrations, and control measures to remediate the exposure. Hazard assessment techniques are used to establish the appropriate ‘how clean is clean enough’ endpoints based on calculated margins of safety (MS), where MS = toxicologically safe concentration/exposure concentration. A successful remedial action endpoint is achieved when the targeted exposure reduction action results in a margin of safety that is greater than 1.0 (MS > 1.0) including the uncertainty of the estimate. This assessment program is carried out in a cost effective step by step tiered approach to guide selection of a remediation endpoint.