Risk Assessment

EKI conducts human health risk assessments to assess whether contaminants detected at a site pose a concern to human health and the environment. EKI often uses risk assessment protocols to develop site-specific risk-based remedial goals and, in some cases, background levels for metals. The results of these assessments inform potential remedial action alternatives and guide the cleanup with the ultimate objective of achieving regulatory agency closure and facilitating the redevelopment of brownfields properties.

For complex sites, EKI completes site-specific risk assessments that evaluate all facets of a site to assess potential human health and environmental risk. A defensible risk assessment requires an understanding of the chemical distribution in environmental media, the definition of the reasonably anticipated land uses, the potentially exposed populations (including the surrounding community), and the potentially complete exposure pathways. Together, these constitute the conceptual site model. Once the conceptual site model is developed, exposures are quantified based on potentially complete exposure pathways, and cumulative risks are calculated. As discussed above, EKI can use these risk assessment assumptions to calculate risk-based remedial goals for site cleanup and risk-based action levels for perimeter air monitoring to mitigate impacts on the surrounding community.

In many jurisdictions, potential risks associated with environmental impact at a site can be quickly and easily assessed by simply comparing chemical data to published screening levels, such as U.S. Environmental Protection Agency Regional Screening Levels or state criteria (e.g., California Department of Toxic Substances Control Screening Levels, Water Board Environmental Screening Levels, Connecticut Remediation Standard Regulations criteria, or Massachusetts Method 1 criteria). In several jurisdictions, these comparisons are sufficient to document the absence of unacceptable risk, and site closure may be achieved. When the screening level risk assessment does not document the absence of unacceptable risk, the data obtained from the assessment is then used to determine whether a comprehensive risk assessment is required, additional investigation is needed, or corrective actions are warranted. EKI has applied various risk-based corrective action methods to address the issues posed by site contamination.