Model Descriptions
2DFATMIC
Application
This model simulates subsurface flow, fate, and transport of contaminants that are undergoing chemical or biological transformations. The model is applicable to transient conditions in both saturated and unsaturated zones.
Processes
The flow module is a Galerkin finite element solution of Richard's equation. The transport module is a hybrid Lagrangian-Eulerian approach, with an adapted zooming and peak capturing algorithm.
Miscellaneous
This model can almost eliminate spurious oscillation, numerical dispersion, and peak clipping due to advective transport.
Contact
Professor G.T. Yeh
814-863-2931
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3DFATMIC
Application
This model simulates subsurface flow, fate, and transport of contaminants that are undergoing chemical or biological transformations. The model is applicable to transient conditions in both saturated and unsaturated zones.
Processes
The flow module is a Galerkin finite element solution of Richard's equation. The transport module is a hybrid Lagrangian-Eulerian approach, with an adapted zooming and peak capturing algorithm.
Miscellaneous
This model can almost eliminate spurious oscillation, numerical dispersion, and peak clipping due to advective transport.
Contact
Professor G.T. Yeh
814-863-2931
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BIOCHLOR
Application
This is a screening model that simulates remediation by natural attenuation of dissolved solvents at chlorinated solvent release sites. BIOCHLOR can be used to simulate solute transport without decay, and solute transport with biodegradation modeled as a sequential first-order process within one or two different reaction zones.
Processes
The program is based on the one-dimensional Domenico analytical solute transport model and includes one-dimensional advection, three-dimensional dispersion, linear adsorption, and biotransformation via reductive dechlorination. Reductive dechlorination is assumed to occur under anaerobic conditions and solvent degradation is assumed to follow a sequential first-order decay process.
Miscellaneous
The program is written as an Excel spreadsheet and, therefore, requires Microsoft Excel to run. The program includes a natural attenuation screening protocol scoring system to help the user determine the potential for reductive dechlorination from site data.
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BIOPLUME II
Application
This is a two-dimensional contaminant transport model used under the influence of oxygen limited biodegradation.
Processes
Processs include advection, dispersion, sorption, biodegradation (aerobic and anaerobic), and re-aeration.
Miscellaneous
This model is based on the two-dimensional solute transport code USGS-MOC.
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BIOPLUME III
Application
This is a two-dimensional contaminant transport model for use under the influence of oxygen, nitrate, iron, sulfate, and methanogenic biodegradation.
Processes
Processes include advection, dispersion, sorption, first order decay, biodegradation through instantaneous, first order, zero order, or Monod kinetics.
Miscellaneous
This model is based on the two-dimensional solute transport code USGS-MOC, but has an integrated, Windows-based graphical user interface for seamless preprocessing and output review. Hydrocarbon source and each active electron acceptor are simulated as separate plumes.
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BIOSCREEN
Application
This is a three-dimensional contaminant transport model for dissolved-phase hydrocarbons in a saturated zone under the influences of oxygen, nitrate, iron, sulfate, and methane limited biodegradation.
Processes
Processes include advection, dispersion, adsorption, first-order decay, and instantaneous reactions under aerobic and anaerobic conditions.
Miscellaneous
This is an easy-to-use screening tool that is based on the Domenico analytical solute transport model.
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CHEMFLO
Application
This model simulates one-dimensional water and chemical movement in the vadose zone.
Processes
Processes include advection, dispersion, first-order decay, and linear sorption.
Miscellaneous
This is a numerical solution model that handles a variety of boundary conditions.
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EvalMNA
Application
Comparison of Initial Year of Review Cycle to Final Year of Review Cycle (.xls) (2 pp, 60 KB)
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FOOTPRINT
Application
This model simulates the length and surface area of BTEX plumes in groundwater, when the plumes are produced from a gasoline spill that contains ethanol.
Processes
This model is based on a modified version of the 1982 Domenico model. This model was modified to allow zero-order decay.
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GEOEAS
Application
This model performs geostatistical analysis of spatially correlated data.
Components
Components include basic statistics, scatter plots, and linear and nonlinear estimation (kriging).
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GEOPACK
Application
This model performs geostatistical analysis of spatially correlated data.
Components
Components include basic statistics, variography, and linear and nonlinear estimation (kriging).
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HSSM
Application
This model simulates flow of light nonaqueous-phase liquid (LNAPL) and transport of a chemical constituent of the LNAPL from the surface to the water table, radial spreading of the LNAPL at the water table, and dissolution and aquifer transport of the chemical constituent.
Processes
Processes include one-dimensional in the vadose zone, radial in the capillary fringe, and two-dimensional vertically averaged analytical solution of the advectiondispersion equation in the saturated zone.
Miscellaneous
This model is based on the KOPT, OILENS, and TSGPLUME models. It is also available in Spanish.
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MODFLOW Manual
Application
This is an instruction manual for the U.S.Geological Survey’s MODFLOW model.
Components
The manual contains a series of 20 problem sets that illustrate by example the use of MODFLOW, including modeling principles, input/output specifics, available options, rules of thumb, and common modeling mistakes.
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MOFAT
Application
This is a two-dimensional flow and transport model of three fluid phases: water, nonaqueous-phase liquid, and gas.
Processes
Processes include advection, dispersion, diffusion, sorption, decay, and mass transfer.
Miscellaneous
This model is finite-element; numerous parameters are required.
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MT3D
Application
This model is a three-dimensional contaminant transport in the saturated zone.
Processes
Processes include advection, dispersion, nonlinear sorption, first-order irreversible decay, and biodegradation.
Miscellaneous
This is a numerical solution model that uses a hybrid method of characteristics and particle tracking. It handles a variety of discretization schemes and boundary conditions and includes the MODFLOW program.
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NAPL Simulator
Application
This model simulates the contamination of soils and aquifers that results from the release of organic liquids, commonly referred to as nonaqueous-phase liquids (NAPLs).
Processes
The simulator is applicable to three interrelated zones: a vadose zone, which is in contact with the atmosphere; a capillary zone; and a water-table aquifer zone. Three mobile phases are accommodated: water, NAPL, and gas. The three-phase k-S-P submodel accommodates capillary and fluid entrapment hysteresis. NAPL dissolution and volatilization are accounted for through rate-limited mass transfer submodels.
Miscellaneous
The numerical solution is based on a Hermite collocation finite element discretization. The simulator provides an accurate solution of a coupled set of nonlinear partial differential equations that are generated by combining fundamental balance equations with constitutive thermodynamic relationships.
Contact
Joseph Guarnaccia
732-914-2516
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OWL
Application
This model evaluates existing monitoring well networks and optimizes the selection new monitoring well locations.
Processes
Processes include calculation of plume migration, based on variations in groundwater flow magnitude and direction. Optimal locations are selected, based on simple analysis of plume locations and the existing monitoring well network.
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PESTAN
Application
This program performs vadose zone modeling of the transport of organic (pesticide) contaminants.
Processes
Processes include advection, dispersion, first-order decay, and linear sorption.
Miscellaneous
This is a screening model; few parameters are required.
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RegressionMNA
Application
Regression MNA (.xls) (3 pp, 56 KB)
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REMFuel
Application
This model simulates the transient effects of groundwater source and plume remediation for fuel hydrocarbons
Processes
This is a contaminant source model based on a power function relationship between source mass and source discharge for multiple fuel costituents, and it can consider partial source remediation at any time after the initial release. The source model serves as a time-dependent mass flux boundary condition to the analytical plume model, where flow is assumed to be one-dimensional. The plume model for each fuel component simulates first order sequential decay and production of one daughter species. REMFuel can also simulate zero order or Monod's kinetics for decay of fuel components in the plume. The decay rates and other reaction coefficients are variable functions of time and distance in the plume. This approach allows for flexible simulation of enhanced plume remediation that may be temporary in time, limited in space, and which may have different effects on different contaminant species in the plume.
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REMchlor
Application
This model simulates the transient effects of groundwater source and plume remediation.
Processes
This is a contaminant source model based on a power-function relationship between source, mass, and discharge. It can consider partial source remediation at any time after release. The source model is a time-dependent, mass-flux boundary condition to the analytical plume model (one-dimensional flow), which simulates first-order sequential decay and production of several species. This model also calculates cancer risks posed by carcinogenic species.
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RETC
Application
This model estimates the soil-water retention curve, unsaturated hydraulic conductivity, and soil model parameters.
Processes
This model uses the parametric equations of Brooks-Corey and van Genuchten, and the pore-size distribution models of Maulem and Burdine.
Miscellaneous
This is an analytical model; it requires relatively few parameters.
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RITZ
Application
This program performs vadose zone modeling of the transport of contaminants associated with oily wastes.
Processes
Processes include water movement, volatilization, degradation, sorption, and leaching.
Miscellaneous
This is an analytical model that requires relatively few parameters.
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UTCHEM 
Application
Originally a three-dimensional finite difference model for multiphase flow, transport and chemical flooding, the UTCHEM code has been modified to transform the model into a general-purpose NAPL simulator. Appropriate physical, chemical, and biological process models have been incorporated into the simulator to create a threedimensional multiphase, multicomponent model that is capable of simulating the fate and transport of NAPLs in the saturated and unsaturated zones of aquifers. The model can be used to simulate the actual field operation of remediation activities, such as surfactant remediation and bioremediation, as well as laboratory experiments with large-scale aquifer models.
Processes
UTCHEM is capable of modeling transient and steady-state, three-dimensional flow and mass transport in the groundwater (saturated) and vadose (unsaturated) zones of aquifers. Physical, chemical, and biological process models important in describing the fate and transport of NAPLs in contaminated aquifers have been incorporated into the simulator. These include multiple organic NAPL phases, the dissolution or mobilization of NAPLs by nondilute remedial fluids, chemical and microbiological transformations, and changes in fluid properties as a site is remediated. The model allows for nonequilibrium interphase mass transfer, sorption, geochemical reactions, and the temperature dependence of pertinent chemical and physical properties. It can simulate the flow and transport of remedial fluids whose density, temperature, and viscosity are variable, including surfactants, co-solvents, and other enhancement agents. The biodegradation model includes inhibition, sequential use of electron acceptors, and co-metabolism, and can be used to model a very general class of bioremediation processes.
Miscellaneous
Biodegradation capabilities have been added to describe the transformation of organic contaminants from NAPL sources. This model can accommodate multiple substrates, electron acceptors, and biological species. A new multiphase capillarypressure and relative permeability function has been added to allow the use of either Brooks-Corey or Van Genuchten capillary pressure functions. New organic and tracer components have been added, as well as additional water tracer components and gas-phase tracers. The number of oil/water tracers has been expanded to allow any number of tracer components. The geochemical option has been extended to allow the modeling of any solid or aqueous species. UTCHEM uses a solution scheme analogous to the Implicit Pressure Explicit Saturation (IMPES) routine, where the pressure is solved for implicitly but concentrations instead of saturations are solved in a flash routine. An energy balance equation includes heat flow between the reservoir and the over- and under-burden rocks.
Contact
Dr. Gary Pope
University of Texas, Department of Petroleum Engineering
Austin, Texas
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Virulo
Application
This is a probabilistic screening model for predicting leaching of viruses in unsaturated soils.
Processes
Monte Carlo is employed to generate ensemble simulations of virus attenuation. The probability of failure is generated to achieve a user-chosen degree of attenuation.
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VLEACH
Application
This model simulates one-dimensional water and chemical movement in vadose zone.
Processes
Processes include advection, sorption, vapor-phase diffusion, and three-phase equilibration.
Miscellaneous
This is a numerical solution and screening model.
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WhAEM
Application
This program delineates capture zones and isochrones of groundwater residence time for the purpose of wellhead protection.
Processes
Processes include steady state, homogeneous, isotropic, advection, and dispersion.
Miscellaneous
This model consists of two independent executables: Geographic Analytic Element Preprocessor (GAEP) and Capture Zone Analytic Element Model (CZAEM).
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WhAEM2000
Application
This model delineates capture zones and isochrones of groundwater residence time for the purpose of source water area delineation and wellhead protection.
Processes
Processes include steady state, homogeneous, isotropic, advection.
Miscellaneous
This model includes a full 32-bit graphical user interface for Windows (95, 98, NT), on-line help, and a tutorial. Working with the WhAEM 2000 document demonstrates modeling practice for a Vincennes, Indiana, case study.
Contact
Stephen R. Kraemer
Phone: 706-355-8340
Fax: 706-355-8302
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WHPA
Application
This model simulates capture zones for pumping wells.
Processes
Processes include steady state and horizontal flow.
Miscellaneous
This model performs particle tracking with analytical, semi-analytical, and numerical modules.
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