Mass Flux Toolkit

mass_flux_main_menu_med2The Mass Flux Toolkit, developed for the Department of Defense ESTCP program, is an easy-to-use, Microsoft® Excel based software tool that enables users to learn about different mass flux approaches, calculate mass flux from transect data, and apply mass flux values to manage groundwater plumes. The Toolkit presents the user with three main options:

  • A module to calculate the total mass flux across one or more transects of a plume, calculate the uncertainty in the calculation, and plot mass flux vs. distance to show the effect of remediation/impact of natural attenuation processes.
  • A module allowing users to perform critical dilution calculations for plumes approaching production wells or streams. An additional feature calculates the capture zone of the supply well and compares it to the transect used to calculate the mass flux, directing the user to alter the transect dimensions if the transect does not encompass the capture zone.
  • A module that provides a review of theory and methods of estimating mass flux.

Uncertainty in mass flux estimates is a key issue in using mass flux as a metric. The Toolkit provides three options for analyzing uncertainty in the total mass flux estimates derived from the transect method. One option utilizes the Monte Carlo approach to analyze uncertainty in the actual concentration, hydraulic conductivity, and gradient measurements. With this tool, groundwater practitioners can estimate the accuracy of the hydrologic measurements that are being used for the mass flux calculation. The second option provides a tool for estimating the contribution of each individual observation to the total mass flux. The third method shows the uncertainty involved in the interpolation scheme that is used to calculate mass flux.

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The Mass Flux Toolkit will give site personnel the capability to compare different mass flux approaches, calculate mass flux from transect data, and apply mass flux to manage groundwater plumes. With this tool, site personnel will be able to perform mass flux calculations more quickly and cheaply, permitting their inclusion in more evaluations of groundwater plumes. With the mass flux data, the progress of natural attenuation and remediation systems can be demonstrated more vividly and directly to regulators, making the entire remediation process clear, effective, and efficient.

Technical Support

Limited technical support is available from Shahla K.Farhat.

System Requirements

Mass Flux Toolkit model requires a computer system capable of running Microsoft® Excel (2000/XP) for Windows (2000/XP) and Microsoft Word for Windows (2000/XP), and reading Adobe Acrobat pdf documents. Mass Flux Toolkit has been updated to run on Excel (2007/2010) for Windows (2003/7).

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.


Click here to download Mass Flux Toolkit (Excel 2007/2010).

Click here to download the Mass Flux Toolkit User's Manual.

Click here to download the instructions for viewing the Mass Flux Toolkit Help File (Excel 2007/2010).

Click here to download Mass Flux Toolkit (Excel 2016)

Unzip all the files to the same folder. The zipped files contain the Mass Flux Toolkit spreadsheet, associated word and pdf files, the help file, and the User’s Manual.

Mass Flux Toolkit (Excel 97-SR1/2000/XP).