Region 8

Fate and Transport Models

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Fate and transport models are used by risk assessors to estimate the movement and chemical alteration of contaminants as they move through environmental media (e.g., air, soil, water, groundwater).

In some cases, the spatial pattern of contamination in a medium at a site may be relatively stable, with little expectation that significant changes will occur over time. For example, lead levels in soil tend to be relatively constant because lead does not degrade or volatilize, and because lead usually does not migrate extensively through soil. In other cases, some chemicals will tend to migrate within the same medium (for example, a plume of chlorinated solvent in groundwater may tend to move away from the source area as time passes), or move from one medium to another (e.g., volatile chemicals in groundwater may tend to migrate upward into soil and from there into outdoor or indoor air). In cases where it is important to understand the rate and extent of these transport processes, mathematical models are often used to predict these processes and estimate the concentrations that are likely to occur. Presented below are links to a number of documents and models that may be useful in modeling various types of fate and transport processes.

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Note: The following are examples of models, which may not be appropriate for every situation. Please consult an expert before using.

Models for Estimating Intrusion of Volatile Chemicals into Buildings from Subsurface Soil and Groundwater

EPA has developed a series of models for estimating indoor air concentrations and associated health risks from subsurface vapor intrusion into buildings. More information on these models.

Models for Estimating Release of Volatile Chemicals into Buildings from Showering and Other Indoor Uses of Water

Andelman, J.B. 1985. Inhalational exposure in the home to volatile organic contaminants of drinking water. Sci. Total Environ. 47:443-460.

Andelman, J. B. 1990. Total Exposure to Volatile Organic Compounds in Potable Water. In: Significance and Treatment of Volatile Organic Compounds in Water Supplies, p. 485-504.

Andelman, J.B., S.M. Meyers, and L.C. Wilder. 1986. Volatilization of organic chemicals from indoor uses of water. In: Chemicals in the Environment. Lester, J.N., R. Perry, and R.M. Sterritt, Eds. Selper Ltd., London, p. 323-330.

Andelman, J.B., S.M. Meyers, and L.C. Wilder. 1986. Volatilization of trichloroethylene and chloroform from an experimental bath and shower system. Extended abstract. Division of Environmental Chemistry, American Chemical Society, Anaheim, California. September 1986.

Foster, S.A., and P.C. Chrostowski. 1986. Integrated household exposure model for the use of tap water contaminated with volatile organic chemicals. Paper presented at the 79th Annual Meeting of the Air Pollution Control Association, Minneapolis, Minnesota, June 22-27, 1986. Paper #86.12.3.

McKone, T.E. 1987. Human exposure to volatile organic compounds in household tap water: the inhalation pathway. Environ. Sci. Technol. 21(12):1194-1201.

Small, M.J., C.R. Wilkes, J.B. Andelman, N.J. Giardino, and J. Marshall. 1990. Inhalation Exposure from Contaminated Water Uses: A Behavioral Model for People and Pollutants. ASCE Environmental Engineering, Washington, D.C. July 9-11, 1990.

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Models for Estimating the Chemical Form of Metals in Water


Models for Estimating Uptake and Bioaccumulation of Chemicals in Plant and Animal Tissues

Exposure Factors and Bioaccumulation Models for Derivation of Wildlife Eco-SSLs (PDF) (111 pp, 5 MB) (Guidance for Developing Ecological Soil Screening Levels (Eco-SSLs), Attachment 4-1; OSWER Directive 9285.7-55, Issued November 2003, Revised February 2005)

A Review and Analysis of Parameters for Assessing Transport of Environmentally Released Radionuclides through Agriculture (PDF) (167 pp, 3 MB) (ORNL-5786, September 1984)

Development and Validation of Bioaccumulation Models for Earthworms (PDF) (53 pp, 492 K) (ES/ER/TM-220, February 1998)
– Appendices A-D (PDF) (47 pp, 340 K)

Development and Validation of Bioaccumulation Models for Small Mammals (PDF) (92 pp, 509 K) (ES/ER/TM-219, February 1998)

Biota Sediment Bioaccumulation Factors for Invertebrates: Review and Recommendations for the Oak Ridge Reservation (PDF) (52 pp, 399 K) (BJC/OR-112, August 1998)

Empirical Models for the Uptake of Inorganic Chemicals from Soil by Plants (PDF) (116 pp, 905 K) (BJC/OR-133, September 1998)

Ecological Risk Analysis: Guidance, Tools, and Applications
Additional guidance documents from Oak Ridge National Laboratory (ORNL)

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