Source History Tool (version 1.0)

 The Source History Tool, developed for the Department of Defense’s ESTCP program, is an easy-to-use, comprehensive, free software tool that can assist site personnel reconstruct long-term contaminant source histories that extend back to the beginning of the original source release. The Tool uses soil core data collected in low permeability zones (low-k zones) to make predictions about the source loading over time, in a forensic approach not unlike the evaluation of tree rings.

SourceHistoryTool_1SourceHistoryTool_2 SourceHistoryTool_3

Features

The Source History Tool attempts to assist site managers and site consultants better understand and reconstruct long-term source histories. A long-term source history, from the beginning of releases at a site to present time, would help confirm a site conceptual model that shows attenuation is a significant process for both the source and the plume, and generate data that are well-suited for use in predicting future concentration and attenuation trends. Reducing the uncertainty associated with assessing long-term concentration trends before a remedy is selected and implemented, could assist site stakeholders select more appropriate remedies and improve effective risk communication with regulators and the public.The primary input data for the Tool are soil concentration vs. depth data from a low-permeability zone. Diffusion of contaminant mass into these zones is a function of the concentration gradient in an adjacent transmissive zone, which can change over time if the source attenuates. Diffusion is a predictable process, and the Tool uses a 1-D model based on Fick’s Law that includes vertical advection and degradation to reconstruct a concentration vs. time history from soil data collected at a single timepoint.In addition, the Toolkit provides a Monte Carlo-type approach to analyze uncertainty in the input parameters such as the porosity, apparent tortuosity factor exponent, fraction organic carbon/distribution coefficient, and constituent half-life. With this tool, groundwater practitioners can evaluate the accuracy of the hydrologic measurements that are being used for the reconstruction of source histories.

Technical Support

Limited technical support is available from Shahla K. Farhat.

System Requirements

The Source History Tool requires a computer capable of running Microsoft® Excel (2007/2010) for Windows 7. Operation requires an IBM-compatible PC equipped with a Pentium or later processor running at a minimum of 450 MHz. A minimum of 256 MB of system memory (RAM) is strongly recommended. Computers not meeting these recommendations will experience slow running times and/or problems with memory.

The Toolkit can also be run on a Macintosh capable of running Office 2011.

Downloads

Unzip all the files to the same folder. The zipped file contains the Source History Tool spreadsheet, the Help file, and the User’s Manual.

Click here to download Source History Tool PC version.

Click here to download Source History Tool Mac version.

Click here to download the Source History Tool User's Manual.