Summary - trdoer20035

Summary

It was the general consensus of workshop participants that risk assessment

should be used to augment and improve the dredged material management

decision-making process. The importance of using risk-based approaches early on

in the current tiered assessment scheme was emphasized. However, it was also

noted that the current dredged material evaluation scheme as outlined in the Ocean

and Inland Testing Manuals (USACE/USEPA 1991, 1998) was adequate for the

vast majority of dredged material management decisions (estimated by some

participants to be 95 percent). Participants suggested that the greatest benefit of

risk-based decision-making would be found by applying risk assessment in the

smaller percentage of projects where there is high uncertainty (e.g., no evidence of

acute toxicity but some elevated bioaccumulation of contaminants).

Recommendations generally fell into two categories: (a) procedural

recommendations (ways to improve the dredged material decision-making process

via incorporation of risk-based approaches) and (b) recommendations for

improving existing assessment tools (models, tests, etc.) so that they can be used

more effectively to make risk-based decisions. Specific recommendations

included:

a. All dredged material evaluations must be preceded by clearly stated

hypotheses and explicit statements of what is to be protected.

b. All dredged material evaluations should include early stakeholder

involvement, especially in the development of the conceptual model.

c. Conceptual exposure models should be used to define and develop

monitoring programs for dredged material disposal sites.

d. Databases on regional sources of information (e.g., region-specific dietary

information for evaluating exposure, data from past dredging projects)

must be developed to ensure consistency/accuracy and reduce cost of risk-

based evaluations of dredged material.

e. Screening-level exposure assessment should be used early in risk-based

evaluations of dredged material to focus limited resources on high priority

issues.

Chapter 5 Summary