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RISKPRO'S SESOIL for Windows User's Guide
<br /> 2. OVERVIEW OF THE SESOIL MODEL
<br /> SESOIL is a one-dimensional vertical transport code for the unsaturated soil zone. It is an
<br /> integrated screening-level soil compartment model and is designed to simultaneously model water
<br /> transport, sediment transport, and pollutant fate The program was developed for EPA's Office
<br /> I of Water and the Office of Toxic Substances (OTS) in 1981 by Arthur D. Little, Inc (ADL)
<br /> ADL updated the SESOIL model in 1984 to include a fourth soil compartment (the original
<br /> model included up to three layers) and the soil erosion algorithms (Bonazountas and Wagner,
<br /> 1984). A comprehensive evaluation of SESOIL performed by Watson and Brown (1985)
<br /> uncovered numerous deficiencies in the model, and subsequently, SESOIL was modified
<br /> extensively by Hetrick et al at Oak Ridge National Laboratory (ORNL) to enhance its
<br /> capabilities (see Hetrick et al , 1986, 1988, 1989)
<br /> SESOIL was developed as a screening-level model, utilizing fewer soil, chemical, and
<br /> meteorological values as input than most other, similar models Output of the SESOIL model
<br /> includes time-varying pollutant concentrations at various soil depths and pollutant loss from the
<br /> unsaturated zone in terms of surface runoff, percolation to the groundwater, volatilization, and
<br /> Idegradation
<br /> The SESOIL model accepts time-varying pollutant loading For example, it is able to simulate
<br /> chemical releases to soil from a variety of sources such as landfill disposal, accidental leaks,
<br /> agncultural applications, leaking underground storage tanks, or deposition from the atmosphere
<br /> Other potential applications of SESOIL include long-term leaching studies from waste disposal
<br /> sites, pesticide and sediment transport on watersheds, studies of hydrologic cycles and water
<br /> balances of soil compartments, and precalibration runs for other simulation models One may
<br /> also run the model to estimate the effect of various site management or design strategies on
<br /> pollutant distributions and concentrations in the environment
<br /> SESOIL can be used as a screening tool in performing exposure assessments OTS used the
<br /> model to predict the behavior of pollutants in soil compartments for analyzing and prioritizing
<br /> chemical exposures A number of studies have been conducted on the SESOIL model including
<br /> sensitivity analyses, comparison with other models, and comparisons with field data
<br /> (Bonazountas et al , 1982, Wagner et al., 1983, Hetrick, 1984, Kincaid et al , 1984, Watson
<br /> and Brown, 1985, Hetrick et al , 1986, Melancon et al , 1986, Hetrick et al , 1988, Hetrick et
<br /> al , 1989) SESOIL has been applied in risk assessments concerning direct coal liquefaction
<br /> (Walsh et al , 1984), incineration of hazardous waste (Holton et al , 1985, Travis et al , 1986),
<br /> the transport of benzene to groundwater (Tucker et al , 1986), and to soil cleanup levels to
<br /> California (Odencrantz et al , 1991, 1992), and to site sensitivity ranking for Wisconsin sods
<br /> for the Wisconsin Department of Natural Resources (Ladwig et al , 1992)
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