CHEMFLO-2000, Interactive Software for Simulating Water and Chemical Movement in Unsaturated Soils

CHEMFLO-2000 enables users to simulate water movement and chemical fate and transport in vadose zones. The software can be used to assist regulators, environmental managers, consultants, scientists, and students in understanding unsaturated flow and transport processes. Water movement and chemical transport are modeled using the Richards and the convection-dispersion equations, respectively. The equations are solved numerically using the finite differences approach.

CHEMFLO-2000 is an upgrade of CHEMFLO Version 1.3 that was released in 1989. In addition to the functions in the previous version, a number of new functions and features were added to CHEMFLO-2000, such as graphic sensitivity analyses and a Java interactive interface to facilitate the simulations of water flow and chemical transport. The new features in CHEMFLO 2000 include:

  • Graphical user interface
  • Enhanced graphics
  • Capability to perform visual sensitivity analyses
  • Improved report generating capability
  • Capability to simulate flow in layered soil
  • Improved numerical methods

Features retained from the previous version include:

  • A focus on interactive use as an educational tool
  • Support for non-uniform initial conditions
  • Support for boundary conditions that change with time
  • Support for a variety of popular models for describing soil properties
  • Ability to define and store soil properties for future use

The CHEMFLO-2000 software package is user friendly. All parameters for implementation of the program could easily be entered through an interactive graphical interface. Users need to know only limited technical terminology and understand the model's mathematical basis and numerical approach. Simulation results can be output as tables and plots. Different types of tables and plots for the output results are available where the hydraulic and chemical properties of interest vary with time and space.

Version 2000
Release Date April 2003
Development Status General Release
Operating System Windows 95/98/NT/2000/XP, Linus, Solaris, Mac OS-X

Minimum System Requirements

CHEMFLO-2000 is written in Java 2. Therefore, it can be used on any computer system supporting Java 2. This includes Windows 95/98/ME/NT/2000/XP, Linux, Solaris, and Mac OS-X. The software requires at least 64 MB random access memory with 128 MB or more recommended. A fixed disk with 30 MB space is required to install the Java Runtime Environment. The compiled software and soil data file requires less than 1 MB additional disk space. The software is written for a computer with a color monitor supporting at least 800x600 pixel resolution.


Currently, the EPA version of CHEMFLO-2000 is in the form of a stand-alone Java application. There are three components of the CHEMFLO package; they are the Java software, the CHEMFLO-2000 program, and the user's manual. These are all available for downloading free of charge.

The CHEMFLO-2000 program continues to be upgraded by the developers; the most current version is available on this Web page. You may also obtain the program from the Oklahoma State University Department of Plant and Soil Sciences Web site CHEMFLO-2000, Interactive Software for Simulating Water and Chemical Movement in Unsaturated Soils Exit, but it may not be the same as the EPA-reviewed version on the Web page.

Java Software

The CHEMFLO application requires the Java 1.3.1 (or later) runtime environment. If that software is already loaded your computer, proceed with step 2. If it is not loaded, download a copy of the runtime environment ORACLE, Sun Developer Network (SDN), Java SE at a Glance Exit. This is a compressed executable file. After downloading it and saving it in a temporary directory, install it on the computer by running the program. It is suggested that you accept the default values presented by the installation software.

Note: If you are using the Linux or Solaris operating system, follow the installation instructions available from the Sun Microsystems site listed above. This installation process is required only once, no matter how many different Java applications are used on your computer.

CHEMFLO-2000 Program

CHEMFLO-2000 Program (zip)(449 K)
The standalone application available for downloading from this site underwent EPA peer review. The application is stored in a ZIP file that is approximately 0.5 MB in size. Save the file in a temporary directory. Extract the files into the directory of your choice. This folder should now contain chemflo.jar, chemflo.bat, and Read Me (txt)(1 pg, 4 K).

US EPA. (2003) User's Manual "CHEMFLO-2000, Interactive Software for Mimulating Water and Cheical Movement in Unsaturated Soils." Publication No. EPA/600/R-03/008.

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