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BIOCHLOR is a screening model that simulates remediation by natural attenuation of dissolved solvents at chlorinated solvent release sites. BIOCHLOR includes three different model types:

The software, programmed in the Microsoft Excel spreadsheet environment and based on the Domenico analytical solute transport model, has the ability to simulate one-dimensional advection, three-dimensional dispersion, linear adsorption, and biotransformation via reductive dechlorination (the dominant biotransformation process at most chlorinated solvent sites). Reductive dechlorination is assumed to occur under anaerobic conditions and dissolved solvent degradation is assumed to follow a sequential first-order decay process.


Version 2.2
Release Date June 2002
Development Status general release
Development Information  
Operating System Windows 95/98/NT, Excel
Development Language  
Intended Audience  
Key Words  
Related Web Sites  

Minimum System Requirements

The BIOCHLOR model requires a computer system capable of running Microsoft Excel 97 or 2000 for Windows. Operation requires an IBM-compatible PC equipped with a Pentium II or later processor. A minimum of 64 MB of RAM is strongly recommended.


Excel 2000 Version: User's manual, installation program, help files, and installation instructions (EXE) (2.3 MB)

Excel 97 Version: User's manual, installation program, help files, and installation instructions (EXE) (2.2 MB)

US EPA. (2000) "BIOCHLOR, Natural Attenuation Decision Support System – User’s Manual, Version 1.0." Publication No. EPA/600/R-00/008.

BIOCHLOR, Natural Attenuation Decision Support System, Version 2.2, User’s Manual Addendum (PDF) (13 pp, 492 KB)March 2002

Installation Instructions

  1. Refer to the BIOCHLOR user's manual and the User's Manual Addendum further instructions.
  2. Download BIOCHLOR22_2000.EXE or BIOCHLOR22_97.EXE to the desired location on your computer.
  3. Run BIOCHLOR22.EXE either by selecting Run from the File menu in Program Manager or by double-clicking on the file BIOCHLOR22.EXE in File Manager (Windows 95/98 Explorer).
  4. Follow the on-screen instructions.
  5. Start the BIOCHLOR2.2 program by clicking Start on your desktop toolbar. Move to Programs and click BIOCHLOR22. You can also use Windows Explorer to open folder BIOCHLOR22 and double-click biochlor22.xls. A message box will ask whether you want to disable or enable the macros. You must enable the macros for BIOCHLOR to operate effectively.

You will need Adobe Reader to view some of the files on this page.
See EPA's PDF page to learn more.


Office of Research & Development | National Risk Management Research Laboratory

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