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Water Resources of the United States

Chemical Mixtures Software Illustration of mixtures



Four programs comprise the chemical-mixtures software. You may save each program individually from the 4 links below, or save all 4 at once with in a unix tar file.

The four programs are:

Dependencies and installation procedures are described in the documentation.

The mixture software should be usable on a variety of computer systems. The programs were written in the Perl programming language (version 5.10.1) and were developed and tested on a 64-bit Sun V440 with 8-GB of memory running SunOS 5.10 (Sun1, in graph). The programs have also been run successfully using:


The following data sets may be useful for verifying proper installation of the software and configuring run-time variables.


The purposes, installation, and usage of the software are documented in U.S. Geological Survey Scientific Investigations Report 2013-5030:

Scott, J.C., Skach, K.A., and Toccalino, P.L. , 2013, Software for analysis of chemical mixtures - composition, occurrence, distribution, and possible toxicity: U.S. Geological Survey Scientific Investigations Report 2013-5030, 27 p., 2 apps., at


Level of support to expect:

Users are encouraged to report bugs and send ideas for future enhancements. Example commands, appendices with software error and warning messages, and installation tips are provided in the documentation. Example datasets are provided on this web site.

Enhancements to add, and Bugs to fix... someday ...

In date done in Version Suggestion From Description of Need
July 29, 2014   Jeff Swartout, EPA, Cincinnati
Enhancement: Add a confidence interval around the expected occurrence percentage (of based on the sample size and the binomial distribution.

Points of contact for the chemical mixtures software:

   Laura Bexfield,
   USGS New Mexico Water Science Center
   Albuquerque, NM

   U.S. Geological Survey
   Office of Water Quality
   412 National Center
   12201 Sunrise Valley Drive
   Reston, VA 20192
   Feedback Form


The time required to run the programs may be hours or days, and will vary depending on the size of the problem and the computing hardware.

Use of trade names is for identification purposes and does not imply endorsement by the U.S. Geological Survey. Perl and applicable Perl packages are free software, made available under an Artistic License.

Although these programs have been used by the USGS, no warranty, expressed or implied, is made by the USGS or the United States Government as to the accuracy and functioning of the programs and related program materials nor shall the fact of distribution constitute any such warranty, and no responsibility is assumed by the USGS in connection therewith.

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Page Contact Information: Ken Skach, USGS Oregon Water Science Center
Page Last Modified: Tuesday, July 29, 2014 14:23:33 EST