Exposure Assessment Workgroup Summary

Exposure Assessment

Workgroup Summary

Environmental risk assessments of dredged material management activities

include an estimate of the potential for human and ecological exposures. The goal

of the workgroup was to make recommendations for developing exposure

assessments at these sites within the context of the current Technical Framework

Document (U.S. Army Corps of Engineers (USACE)/U.S. Environmental

Protection Agency (USEPA) 1992) and the sediment evaluation procedures

(USACE/USEPA 1991, 1998). This section summarizes the exposure assessment

workgroup discussions and recommendations.

When and Where should Risk

Assessment be Applied?

Risk assessment should apply to only that small fraction of sites where

application of the current procedures results in an uncertain decision. The

consensus of the group was that the large majority of dredged material

management decisions (estimated within the group as 95 percent) have an

adequate degree of certainty within the existing approaches. However, among the

remaining 5 percent, the decision-making process is so uncertain that it requires an

integration of risk assessment within the technical framework and sediment

evaluation procedures. Workgroup members felt that the USACE should map a

pathway for using risk assessment which provides a consistent, documented, and

fully accountable approach to remove or address the uncertainty inherent in these

5 percent of decisions.

The group also recommended that the risk assessment approach be

implemented from the start of the planning process because it is often not possible

to predict from the early tiers whether a site decision will require risk assessment.

However, they cautioned against implementing risk assessment without explicitly

recognizing its role in a site-specific, decision-making process. Specifically:

a. Risk assessment should be integrated into the current tiers without making

sweeping changes to the existing procedures.

Chapter 2 Exposure Assessment Workgroup Summary