Software review by courtesy of IGWMC and CSM
By John E. McCray and Jeffrey A.K. Silva

Colorado School of Mines, Golden, CO

The UTCHEM 6.1 software package is capable of modeling transient and steady-state 3D advective and dispersive flow and mass transport in saturated and unsaturated porous media.  It has been used to simulate field-scale problems and laboratory experiments. It has a 3-phase formulation (relative permeability, capillary pressure, etc), and can simulate movement of aqueous and NAPL phases, but cannot simulate contaminant vapor movement. The software allows for changes in fluid properties as a site is remediated; heterogeneous aquifer properties; variable density/viscosity; addition of remedial fluids, including surfactants, cosolvents, among others; and dissolution/mobilization of NAPLs.  UTCHEM can simulate equilibrium and nonequilibrium interphase mass transfer, including dual-domain transport, sorption (linear and non-linear), and NAPL dissolution. NAPL mixtures can be simulated, but constant NAPL-water partitioning coefficients are assumed instead of using Raoult’s law to permit dynamic NAPL dissolution.  The biodegradation model includes sequential electron-acceptor use and cometabolism. The geochemical option allows for modeling of any solid or aqueous species.   Researchers at CSM have been using UTCHEM for simulation of polymer floods in ground-water remediation applications. Two GUIs are available. A stand-alone GUI can be obtained from Dr. Gary Pope at the University of Texas. We recommend Pope’s GUI for 1D and 2D problems. A limited version of UTCHEM is included in the U.S. DoD Groundwater Modeling System (GMS), which is useful when importing GIS data to set up a 3D model.  The FORTRAN source code, along with sample input and output files, are available at no charge from the EPA at www.epa.gov/ada/csmos/models/utchem.html

Rating System
5=Excellent, 4=Very Good, 3=Good, 2=Satisfactory, 1=Poor

Ease of Use
Multiphase flow, Transport, and Remediation
Best Feature

Multiple Processes

Worst Feature

No Vapor Transport

Overall Rating