Risk Assessment

Risk assesment and corrective action: For many years, risk assessment has been a valuable interpretive tool to define the relative significance of contamination in food, soil, water, and air. Since their introduction over a decade ago, risk assessment methodologies have continued to improve and now provide a valuable tool to reduce costs and close environmentally distressed sites.

Risk-Based Corrective Action (RBCA) requires the identification of specific contaminant levels and the site-specific evaluation of potential exposure pathways. To determine the appropriate cleanup level for a site, a sufficient amount of data must be obtained to make reasonable judgments on the type of exposure at a site. The American Environmental Consultants staff is experienced in all aspects of risk assessment, including collecting, compiling, and evaluating the following:

• The contaminant distribution at the site
• The media which is contaminated (soil or groundwater)
• The exposure pathway (e.g., hydrogeologic information or institutional controls)
• Potential receptors
• The intended site use

The purpose of the risk based corrective action is to provide site owners with a mechanism to efficiently demonstrate that site specific characteristics, such as as geology, hydrogeology, engineered barriers and institutional controls provide sufficient protection to human health and the environment. The risk based exposure pathways that are generally considered for a risk based corrective action consist of drinking water ingestion, ingestion of soils, inhalation of soils, and possible dermal contact. For most sites, a risk-based approach will reduce the costs and time required to achieve closure.

Although risk assessment was once reserved for only costly Cercla SuperFund sites, today this remedial decision-making tool is increasingly used for sites of all sizes and complexities for setting cleanup criteria.