Modeling Subsurface Petroleum Hydrocarbon Transport

Latest changes to the Web Course...

7-30-2006 An applet has been added to calculate uncertainty in all input parameters of the Johnson-Ettinger model for indoor air contamination. This appledt was used in preparing the paper: Tillman, Fred D and James W. Weaver, 2006, Uncertainty from Synergistic Effects of Multiple Parameters in the Johnson and Ettinger (1991) Vapor Intrusion Model, Atmospheric Environment, 40(22) 4098-4112.
7-30-2005 Unit conversions for indoor air concentrations have been added. These address the differences between concentrations given on a mass basis and those given as parts per million or parts per billion.

Page author: Jim Weaver, of U.S. EPA, Office of Research and Development, Athens, Georgia who last modified this content on: June 25, 2006