EPA-VHS is a screening level model to predict maximum concentration of a pollutant at a prescribed distance downstream from a continuous source (at the compliance point). The model is based on an analytical solution for the transport of a conservative constituent in a homogeneous, isotropic aquifer with one-dimensional, horizontal, steady-state flow and dispersion perpendicular to the flow path. The model assumes zero retardation, a continuous input source, and saturated conditions. The program package contains two versions:

1. the modified EPA version as published in the Federal Register, 50 FR 4888 6, November 27, 1985; and
2. the original VHS model as published by Domenico and Palciauskas in Ground Water, Vol. 20, No. 3, pp. 301-311, 1982. EPA-VHS is menu-driven and facilitates interactive data entry and editing.
   The program can be used with either metric or U.S. customary units. For instructional purposes the program contains a set of realistic default values for the input variables, some of which are values adopted or required by EPA.

This menu-driven program facilitates interactive data entry and editing. Results are displayed on screen in tabular format. EPA-VHS is distributed with source code and executable image. The program documentation includes installation instructions, and excerpts from the description in the Federal Register, and in Domenico and Palciauskas (1982).

SYSTEM REQUIREMENTS

• Intel 80i86 based computer or compatible
• 256 Kb RAM
• a floppy disk drive
• DOS 2.0 or higher
• CGA (no graphics included)

Author: P.K.M. van der Heijde (IGWMC)