Models hazardous waste site remediation

Hence risk assessment criteria must be established so that there can be developed a national priority list of the hazardous sites that require remedial action. EPA has adopted the Mitre Model for assessing the risks and ranking waste sites. There is some criticism of this model, and there are a number of as yet unanswered questions about its application. Formal cost/benefit analysis will not be used, and risk assessment will be on a case-by-case basis. EPA will thus be developing its knowledge base and procedures as it carries out the program. 

This uncertainty has resulted in a patchwork of remedial projects. Although each project has been beneficial in finding and removing hazards or at least increasing the knowledge base about, waste and inefficiency have been major by-products due to the lack of a comprehensive plan. For example, most properties were sampled for arsenic. Now a repeat mobilization will have to be conducted to sample for a small handful of other toxic metals and constituents, which could have been sampled for in the first event. It is in an effort to minimize such future duplication of effort and data gaps that the District of Columbia has tackled the enormity of a comprehensive planning document with this Conceptual Site Model. 

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