Water Resources Applications Software

Geochemical || Ground Water || Surface Water || Water Quality || General

Summary of WATEQ4F

                 redox elements in natural waters


       The program prompts for the input and output file names.

       If no <infile>.csv file name is specified the input file name defaults
       to wateq4f.csv.

       If only the input file name is specified, then the output file
       names default to <infile>.out and <infile>.eqp.

       WATEQ4F is a Fortran 77 version of the PL/1 computer program for the
       geochemical model WATEQ2, which computes major and trace element
       speciation and mineral saturation for natural waters.

       Version 2.46 2002/10/23 - Updated As thermodynamic data base, input
          and output files readable using a spreadsheet program. Options
          for specifying components, aqueous species, and mineral saturation
          indices to be written to the spreadsheet-compatible output file.
          See source code and readme file for specifics.

       Version 2.3 1994/05/20 - Improved file opening procedure and bug
          fixes. See source code for specifics.

       Version 2.0 Jan. 1990 - Added nine Eh options, modified print
          options, added uranium calculations, used new thermodynamic data
          and reactions from Grenthe and others (1990); otherwise data from
          Langmuir (1978), changed K values for various species, allow
          input of analytical data in MMOL. See source code for specifics.

       Version 1.1 Jan. 1990 - Added Selenium calculations, output charge
          balance, recoded several reactions, added several solute species,
          revised thermodynamic table 2. See source code for specifics.

       WATEQ4F and WQ4FINPT are written in Fortran 77 with the following
       extensions: use of include files and internal files for list-
       directed I/O. Generally, the program is easily installed on most 
       computer systems. The code has been used on UNIX-based computers 
       and DOS-based 386 or greater computers having a math coprocessor 
       and 2 mb of memory.

       Nordstrom, D.K., and Archer, D.G., 2002, Arsenic thermodynamic data
          and environmental chemistry, In Arsenic in Ground Water, A.H.
          Welch and K.G. Stollenwerk, eds., Kluwer Publishers, p. 1-26.

       Ball, J.W., and Nordstrom, D.K., 1998, Critical evaluation and 
          selection of standard state thermodynamic properties for 
          chromium metal and its aqueous ions, hydrolysis species, 
          oxides, and hydroxides: Journal of Chemical and Engineering 
          Data, v. 43, p. 895-918.

       Ball, J.W., and Nordstrom, D.K., 1991, User's manual for WATEQ4F,
          with revised thermodynamic data base and test cases for
          calculating speciation of major, trace, and redox elements in
          natural waters: U.S. Geological Survey Open-File Report 91-183,
          189 p. (Revised and reprinted August 1992.)

       Nordstrom, D.K., Plummer, L.N., Langmuir, Donald, Busenberg,
          Eurybiades, May, H.M., Jones, B.F., and Parkhurst, D.L., 1990,
          Revised chemical equilibrium data for major water-mineral
          reactions and their limitations, in Melchior, D.C., and Bassett,
          R.L., eds., Chemical modeling in aqueous systems II:  Washington
          D.C., American Chemical Society Symposium Series 416, p. 398-413.

       Parkhurst, D.L., 1995, User's guide to PHREEQC--a computer program
          for speciation, reaction-path, advective-transport, and inverse
          geochemical calculations: U.S. Geological Survey Water-Resources
          Investigations Report 95-4227, 143 p.

       Plummer, L.N., Parkhurst, D.L., Fleming, G.W., and Dunkle, S.A.,
          1988, A computer program incorporating Pitzer's equations for
          calculation of geochemical reactions in brines: U.S. Geological
          Survey Water-Resources Investigations Report 88-4153, 310 p.

       Plummer, L.N., Prestemon, E.C., and Parkhurst, D.L., 1991, An
          interactive code (NETPATH) for modeling NET geochemical reactions
          along a flow PATH:  U.S.  Geological Survey Water-Resources
          Investigations Report 91-4078, 227 p.

       Plummer, L.N., Prestemon, E.C., and Parkhurst, D.L., 1994, An
          interactive code (NETPATH) for modeling NET geochemical reactions
          along a flow PATH--version 2.0:  U.S. Geological Survey Water-
          Resources Investigations Report 94-4169, 130 p.

       Parkhurst, D.L., and Plummer, L.N., 1993, Geochemical models, in
          Alley, W.M., ed., Regional ground-water quality: New York, Van
          Nostrand Reinhold, chap. 9, p. 199-225.

       Plummer, L.N., 1984, Geochemical modeling: A comparison of forward
          and inverse methods, in Hitchon, B., and Wallick, E.I., eds.,
          Proceedings First Canadian/American Conference on
          Hydrogeology--Practical Applications of Ground Water
          Geochemistry, Banff, Alberta, Canada: Worthington, Ohio, National
          Water Well Association, p. 149-177.

       WATEQ4F is not currently taught in any of the USGS National Training
       Center courses.

          U.S. Geological Survey
          James Ball
          3215 Marine Street
          Boulder, CO  80303

          U.S. Geological Survey
          Hydrologic Analysis Software Support Program
          437 National Center
          Reston, VA 20192

       Official versions of U.S. Geological Survey water-resources analysis
       software are available for electronic retrieval via the World Wide
       Web (WWW) at:


       and via anonymous File Transfer Protocol (FTP) from:

         (path: /pub/software).

       The WWW page and anonymous FTP directory from which the WATEQ4F
       software can be retrieved are, respectively:


       netpath(1) <> - Interactive program for calculating NET
                    geochemical reactions and radiocarbon dating
                    along a flow PATH
       phreeqc(1) <> - A program for aqueous geochemical calculations
       phrqpitz(1) <> - A program for geochemical calculations in brines

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