DGCHANGE Software and User’s Guide

DGCHANGE v1.0 is a tool for estimating dissolved contaminant concentration reductions with time in near-field monitoring wells down-gradient of permeable treatment barriers (PTBs). In this spreadsheet-based tool, the aquifer is represented as a series of horizontal layers and the user enters layer-specific aquifer characteristics. The output is presented graphically in three main formats: a) a cross-section snapshot of dissolved concentrations along the groundwater flow path at some user-specified time, b) a table of dissolved concentrations vs. time in each layer at some user-defined down-gradient location, and c) as a plot of expected monitoring well dissolved concentration vs. time at some user-defined down-gradient location for layer thickness- and layer discharge-weighted averages.

The underlying fundamental basis and governing equations upon which DGCHANGE v1.0 is based are described in the User’s Guide.