Dredging Risk Assessment Modeling Applications(DRAMA) for Evaluation of Dredging Impacts

摘要

Environmental risk assessment is a complex process requiring multi-disciplinary expertise.To facilitate screening level risk assessments PC-based decision support tools have been and are being developed and applied to numerous sites for estimating both human and ecological risks from exposures to hazardous and radioactive wastes. While these decision support tools have proven successful in providing site-specific risk estimates for human health at Superfund sites, they have not been adapted for use in evaluating the potential impacts of dredging operations. The Dredging Risk Assessment Modeling Applications(DRAMA) are being developed as a PC-based,environmental risk assessment decision support tool using existing models,databases,frameworks,and systems. Numerous tools and protocols have been developed to evaluate exposure and effects of contaminant pathways at dredging operations.The Automated Dredging and Disposal Alternatives Modeling System(ADDAMS)contains models and tools to estimate exposure concentrations and effects data.The USACE/EPA Evaluating Environmental Effects of Dredged Material Management Alternatives–A Technical Framework is an effects-based evaluation that is compatible with the ecological risk assessment paradigm. The backbone of DRAMA is the Framework for Risk Analysis in Multimedia Environmental Systems(FRAMES).FRAMES is a multi-stage object-oriented,PC-based environment for integrating exposure and effects models and databases to perform human health and ecological risk characterization and uncertainty quantification in multi-media.DRAMA is the integration of ADDAMS and dredging effects databases with FRAMES. To facilitate rapid application of DRAMA and aid in problem formulation, pre-set assessment scenarios for common dredging and disposal operations are incorporated as conceptual models of the contaminant exposure sources, pathways,and receptors.The pre-set scenarios include selection of exposure pathway models,exposure effects databases,and risk characterization tools and provide linkages between the components.Example pre-set scenarios are no-action,dredging,open-water disposal,capping,and upland disposal. DRAMA will make the decision process more explicit,facilitate uniform application of risk models,perform risk assessment quantitatively,and provide probabilistic description of risk&uncertainty.