Selection Criteria for Mathematical Models Used in Exposure Assessments: Surface Water Models
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Prior to the issuance of the Guidelines for Estimating Exposures in 1986, the U.S. Environmental Protection Agency (EPA) published proposed guidelines in the Federal Register for public review and comment. The purpose of the guideline is to provide a general approach and framework for carrying out human and nonhuman exposure assessments for specific pollutants. As a result of the review process, four areas were identified that required further research. One of these was the area of selection criteria for mathematical models used in exposure assessment. The purpose of the document is to present criteria which provide a means for selecting the most appropriate mathematical model(s) for conducting an exposure assessment related to surface water contamination. A concerted effort was made to provide general background information regarding surface water flow and contaminant transport and to characterize the important assumptions and limitations of existing models. These include a detailed summary matrix and model writeups for ten runoff models, twelve surface water flow models, and twelve contaminant transport models that have been used previously by EPA to study surface water quality problems.