TracerLPM (Version 1)
An Excel® Workbook for Interpreting Groundwater Age Distributions from Environmental Tracer Data

TracerLPM is an interactive Excel® (2007 or later) workbook program used to evaluate groundwater age distributions from environmental tracer data by using lumped parameter models (LPMs). User-defined age distributions, such as those determined from particle tracking, and those generated from LPMs can be used to calculate past and future concentrations of non-point source contaminants and in evaluating the response of wells or receptors to changes in source loading using TracerLPM.

Software Download

Version 1.1.0, January 15, 2020

Operates on systems running Windows XP or later.

TracerLPM Graphs


Version History

Version Date Description
1.0 7/19/2012 Initial Release
1.0 7/25/2012 Re-release of initial release with installation icons and error trapping updates to code.
1.0.1 8/30/2012 Minor fix to scaling factor on TracerInput worksheet
1.0.1 03/07/2014 Re-release of version 1.0.1 with updated TracerLPM document (eqn. edits in Appendix A)
1.0.2 03/25/2015 Fix to TracerTracerFits and TimeSeriesFits that prevented tracers with 0 concentration from being included in optimization.
Updated air curves for CFCs and SF6 in northern hemisphere based on data from Reston Age Dating Lab. Values after January 2014 were interpolated using a linear trend of data between January 2012 and 2014.
1.1.0 01/15/2020 Adjusted dates on the TracerInput worksheet to work with tracer records up to year 2030.
Added tracer input datasets for tritium based on Michel and others, 2018 report.
Added tracers for argon-39, krypton-85, and krypton-81.
Fixed the southern hemisphere curves for CFC-11 and CFC-12, which were switched.


Jurgens, B.C., Böhlke, J.K., and Eberts, S.M., 2012, TracerLPM (Version 1): An Excel® workbook for interpreting groundwater age distributions from environmental tracer data: U.S. Geological Survey Techniques and Methods Report 4-F3, 60p. (Revised March 2014)

Other Resources

For reporting bugs or questions about the program, please contact:

Bryant Jurgens, Hydrologist