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Surface Water

• Surface Water Model includes

1. GNOME
2. MIKE BASIN
3. QUAL2E
4. HSCTM2D
5. HSPF
6. MINTEQA2
7. P-ROUTE
8. GCSOLAR
9. Visual Plumes
10. SMPTOX3
11. TMDL
12. WASP
13. WATERSHEDSS
14. PRMS
15. GENSCN
16. SWPROD

Model name: GNOME
Website: http://response.restoration.noaa.gov/software/gnome/gnome.html

@ Summary of the model
GNOME (the General NOAA Oil Modeling Environment) is a free computer program you can use to predict how wind, currents, and other processes might move and spread oil spilled on the water. Learn how predicted oil trajectories are affected by inexactness ("uncertainty") in current and wind observations and forecasts. See how spilled oil is predicted to change chemically and physically ("weather") during the time that it remains on the water surface.

Model name: MIKE BASIN
Website: www.scisoftware.com

@ Summary of the model
MIKE BASIN combines ArcView GIS with water resource modeling for solving allocation, water quality, reservoir operation, and other hydrologic problems. MIKE BASIN is the art of keeping it simple - minimum data requirements, simple process models, a minimum of numerical computations. Yet MIKE BASIN represents all elements of water resource modeling: users, various types of reservoirs, hydropower, surface water, groundwater, rainfall-runoff, non-point pollution, and water quality processes. MIKE BASIN can be linked to Microsoft Excel, among others for general-purpose optimization. MIKE BASIN uses the full strength of GIS, database integration, catchment delineation, www, results maps - ideal for communicating with non-technical audiences.

Model name: QUAL2E
Website: www.cee.odu.edu
Website: www.epa.gov

@ Summary of the model
The Enhanced Stream Water Quality Model (QUAL2E) is applicable to well mixed, dendritic streams. It simulates the major reactions of nutrient cycles, algal production, benthic and carbonaceous demand, atmospheric reaeration and their effects on the dissolved oxygen balance. It can predict up to 15 water quality constituent concentrations. It is intended as a water quality planning tool for developing total maximum daily loads (TMDLs) and can also be used in conjunction with field sampling for identifying the magnitude and quality characteristics of nonpoint sources. By operating the model dynamically, the user can study diurnal dissolved oxygen variations and algal growth. However, the effects of dynamic forcing functions, such as headwater flows or point source loads, cannot be modeled with QUAL2E. The QUAL2E Windows interface was developed to make the model more user friendly. It provides input screens to facilitate preparing model inputs and executing the model. It also has help screens and provides graphical viewing of input data and model results.

The model can be used to study the impact of waste loads on instream water quality. It can also be used to identify the magnitude and quality characteristics of non-point waste loads as part of a field sampling program. The user can: Model effects of diurnal variations in meteorological data on water quality - primarily dissolved oxygen and temperature. Examine diurnal dissolved oxygen variation caused by algae growth and respiration.

The model is applicable to dendritic streams that are well mixed. It assumes that the major transport mechanisms, advection and dispersion, are significant only along the main direction of flow (longitudinal axis of the stream or canal). It allows for multiple waste discharges, withdrawals, tributary flows, and incremental inflow and outflow. It also has the capability to compute required dilution flows for flow augmentation to meet any prespecified dissolved oxygen level. Hydraulically, QUAL2EU is limited to the simulation of time periods during which both the stream flow in river basins and input waste loads are essentially constant. QUAL2EU can operate either as a steady-state or as a dynamic model, making it a very helpful water-quality planning tool. When operated as a steady-state model, it can be used to study the impact of waste loads (magnitude, quality and location) on instream water quality and also can be used in conjunction with a field sampling program to identify the magnitude and quality characteristics of nonpoint source waste loads. By operating the model dynamically, the user can study the effects of diurnal variations in meteorological data on water quality (primarily dissolved oxygen and temperature) and also can study diurnal dissolved oxygen variations due to algae growth and respiration. However, the effects of dynamic forcing functions, such as headwater flows or point loads, cannot be modeled in QUAL2EU.

QUAL2EU allows the modeler to perform uncertainty analysis on the steady state water quality simulations. With this capability, the user can assess the effect of model sensitivities and of uncertain input data on model forecasts. Quantifications of the uncertainty in model forecasts will allow assessment of the risk (probability of a water quality variable being above or below an acceptable level. The uncertainty methodologies provide the means whereby variance estimates and uncertainty prediction can become as much a part of water quality modeling as estimating expected values is today. An evaluation of the input factors that contribute most to the level of uncertainty will lead modelers in the direction of most efficient data gathering and research. In this manner the modeler can assess the risk of imprecise forecasts, and recommend measures for reducing the magnitude of that imprecision.

Model name: HSCTM2D
Website: www.epa.gov
Website: http://www.cee.odu.edu/model/hsctm2d.php

@ Summary of the model
The Hydrodynamic, Sediment, and Contaminant Transport Model (HSCTM2D) is a finite element modeling system for simulating two-dimensional, vertically-integrated, surface water flow (typically riverine or estuarine hydrodynamics), sediment transport, and contaminant transport. The modeling system consists of two modules, one for hydrodynamic modeling (HYDRO2D) and the other for sediment and contaminant transport modeling (CS2D). One example problem is included. The HSCTM2D modeling system may be used to simulate both short term (less than 1 year) and long term scour and/or sedimentation rates and contaminant transport and fate in vertically well mixed bodies of water.

Model name: HSPF
Website: www.epa.gov
Website: www.cee.odu.edu/model/hspf.php

@ Summary of the model
Hydrological Simulation Program - FORTRAN (HSPF) is a comprehensive package for simulation of watershed hydrology and water quality for both conventional and toxic organic pollutants. HSPF incorporates watershed-scale ARM and NPS models into a basin-scale analysis framework that includes fate and transport in one dimensional stream channels. It is the only comprehensive model of watershed hydrology and water quality that allows the integrated simulation of land and soil contaminant runoff processes with In-stream hydraulic and sediment-chemical interactions. The result of this simulation is a time history of the runoff flow rate, sediment load, and nutrient and pesticide concentrations, along with a time history of water quantity and quality at any point in a watershed. HSPF simulates three sediment types (sand, silt, and clay) in addition to a single organic chemical and transformation products of that chemical.

Model name: MINTEQA2
Website: www.cee.odu.edu/model/minteqa_unix.php

@ Summary of the model
MINTEQA2, a geochemical equilibrium speciation model for dilute aqueous systems, is an update of MINTEQ that was developed by combining the fundamental mathematical structure of MINEQL with the thermodynamic data base of WATEQ3.

MINTEQA2 can be used to calculate the equilibrium composition of dilute solutions in laboratory or natural aquatic systems. It can be used to calculate the mass distribution between dissolved, adsorbed, and multiple solid phases under a variety of conditions.

MINTEQA2 is accompanied by an interactive program PRODEFA2, that is used to create MINTEQA2 input files. With PRODEFA2, user can access species available in MINTEQA2 thermodynamic data base and define other aqueous, solid, and/or adsorption species not present in the data base. MINTEQA2 user should have a scientific or engineering background with at least one year of introductory chemistry. Additional experience with thermodynamics would be very helpful.

Model name: P-ROUTE
Website: http://www.cee.odu.edu/model/p-route.php

@ Summary of the model
P-ROUTE, a screening-level Pollutant Routing model is a simple routing model that estimates aqueous point and non-point source pollutant concentrations on a reach by reach flow basis, using 7Q10 or mean flow. It is a Windows-based interface which can estimate surface water concentrations, based on point and non-point source inputs.

P-ROUTE is similar to the Routing and Graphical Display System (RGDS) model; however it utilizes an improved method of estimating average reach concentration of a pollutant. The basic capabilities of the model include the following; Downstream modeling of point and non-point source pollutants, Identification of discharge facilities by reach of all modeled reaches, Identification of points for water sampling or withdrawal and the calculation of the final concentration for each of these points, Identification of a non-point load for each modeled reach, and The system supports transport and decay for two flow regimes: 7Q10 low flow and mean flow.

Model name: GCSOLAR
Website: www.epa.gov

@ Summary of the model
GCSOLAR program is a set of routines that computes direct photolysis rates and half-lives of pollutants in the aquatic environment. The half-lives are calculated as a function of season, latitude, time-of-day, depth in water bodies, and ozone layer thickness. This program operates in an interactive screen mode to facilitate data and program command entry by the user. Input values, with few restrictions, are format free. The user controls program flow by entering program execution commands. This release (1.10 February 1988 and 1.20 July 1999) of the GCSOLAR program differs from earlier versions of the program in that it permits the user to compute photolysis rate constants as a function of elevation above sea level. This is implemented with the GCSOLAR ELEVATION command. For a complete discussion of the chemistry associated with this program, refer to the publication, "Rates of Direct Photolysis in Aquatic Environment", R. G. Zepp and D. M. Cline, Environmental Science and Technology, 11:4, PP 359- 366 (1977).

Model name: Visual Plumes
Website: www.epa.gov

@ Summary of the model
The Visual Plumes model system is a Windows-based software application for simulating surface water jets and plumes. It also assists in the preparation of mixing zone analyses, Total Maximum Daily Loads (TMDLs), and other water quality applications generalized framework for modeling contaminant fate and transport in surface waters. Based on the flexible compartment modeling approach, it can be applied in one, two or three dimensions and is designed to permit easy substitution of user- written routines into program structure. Problems studied using WASP framework include biochemical oxygen demand and dissolved oxygen dynamics nutrients and eutrophication, bacterial contamination, and organic chemical and heavy metal contamination.

Model name: SMPTOX3
Website: www.epa.gov

@ Summary of the model
U.S. EPA regulatory programs have sponsored development of an interactive computer program for performing waste load allocations for toxics -- Simplified Method Program - Variable Complexity Stream Toxics Model (SMPTOX3). SMPTOX3 provides user-friendly access to a technique for calculating water column and stream bed toxic substance concentrations resulting from point source discharges into streams and rivers. It predicts pollutant concentrations in dissolved and particulate phases for water column and bed sediments and total suspended solid. SMPTOX3 provides a user-friendly microcomputer program for performing toxics modeling. It contains a full screen editor to facilitate the entry and modification of inputs. Separate simulation routines are provided for model calibration, waste load allocation, and sensitivity analysis. Each routine provides high resolution graphics of model results during program operation. Inputs and results can also be routed to a printer.

Model name: TMDL USLE
Website: www.epa.gov

@ Summary of the model
The Total Maximum Daily Load (TMDL) Universal Soil Loss Equation (USLE) model is a Windows-based software application for estimating diffuse sediment source loads within a watershed framework. The user interface is similar to a spreadsheet and allows users to easily select and enter parameters used to estimate sediment loading.

Model name: WASP
Website: www.epa.gov

@ Summary of the model
The Water Quality Analysis Simulation Program (WASP) is a generalized framework for modeling contaminant fate and transport in surface waters. Based on the flexible compartment modeling approach, it can be applied in one, two or three dimensions and is designed to permit easy substitution of user- written routines into program structure. Problems studied using WASP framework include biochemical oxygen demand and dissolved oxygen dynamics nutrients and eutrophication, bacterial contamination, and organic chemical and heavy metal contamination. Two WASP models are provided: Toxics, TOXI5, combines kinetic structure with WASP transport structure and simple sediment balance algorithms to predict dissolved and sorbed chemical concentrations in the bed and overlying waters; dissolved oxygen /eutrophication, EUTRO5, combines kinetic structure with WASP5 transport structure to predict DO and phytoplankton dynamics affected by nutrients and organic material.

Model name: WATERSHEDSS
Website: www.epa.gov

@ Summary of the model
An Internet-based decision support and educational software system, WATERSHEDSS (WATER, Soil, and Hydro-Environmental Decision Support System) was developed to assist managers of predominantly agricultural watersheds in defining water quality problems and selecting appropriate nonpoint source (NPS) pollution control measures. The Final Project Report, Understanding The Role of Agricultural Landscape Feature Function and Position in Achieving Environmental Endpoints, was submitted in fulfillment of U.S. Environmental Protection Agency Cooperative Agreement # CR822270 by North Carolina State University. The report covers the period from October 1, 1993, through September 30, 1996, and was completed as of December 23, 1996. For a copy of the report, download and execute the file WATERSHED.EXE found in the Download section below.

Model name: PRMS
Website: http://water.usgs.gov/software/prms.html

@ Summary of the model
PRMS is a modular-design, deterministic, distributed-parameter modeling system developed to evaluate the impacts of various combinations of precipitation, climate, and land use on streamflow, sediment yields, and general basin hydrology. Basin response to normal and extreme rainfall and snowmelt can be simulated to evaluate changes in water-balance relationships, flow regimes, flood peaks and volumes, soil-water relationships, sediment yields, and ground-water recharge. Parameter-optimization and sensitivity analysis capabilities are provided to fit selected model parameters and evaluate their individual and joint effects on model output. The modular design provides a flexible framework for continued model-system enhancement and hydrologic-modeling research and development.

Model name: GENSCN
Website: http://water.usgs.gov/software/genscn.html

@ Summary of the model
Model name: GENSCN
Website: http://water.usgs.gov/software/genscn.html
Summary of the model
Analyzing and managing the high volumes of input and output of complex river basin models is a major task. These models are used to simulate water quantity and quality for numerous scenarios of changes in land use, land-use management practices, and water-management operations. To assist with that process, an interactive computer program, GENeration and analysis of model simulation SCeNarios (GenScn), was developed to create simulation scenarios, analyze results of the scenarios, and compare scenarios

Model name: SWPROD
Website: http://water.usgs.gov/software/swprod.html

@ Summary of the model
The SWPROD program calculates daytime net productivity, night respiration, and total community metabolism from a diel series of dissolved oxygen, temperature, and salinity measurements. An Odum approach is used for the solution of the oxygen-balance equation at a single station in a stream or as a difference between upstream and downstream stations. Net oxygen production and subsequent community metabolism of horizontal lake segments are calculated assuming a one-dimensional model using a finite-difference equation. The results are useful for general aquatic ecosystem characterization and as input to water-quality models for dissolved-oxygen analysis of aquatic environments. SWPROD is a revision of the USGS program J330.

Ground Water

• Ground Water Model includes

1. MODFLOW
2. MT3D
3. FEFLOW
4. ChemStat
5. RBCA Tier 2 Analyzer
6. UTCHEM
7. AQUA3D
8. BALANCE
9. BIOF&T 3-D
10. Bioplume III
11. ChemFlux
12. GFLOW 2000
13. HSSM
14. HST3D
15. Mars 2-D/3-D
16. MicroFEM
17. SLAEM / MLAEM Overview
18. MOC
19. MOCDENSE
20. SHARP
21. MOC3D
22. 2DFATMIC
23. 3DFATMIC
24. FEMWATER/LEWASTE
25. BIOSLURP
26. MS-VMS

Model name: MODFLOW
Website: www.scisoftware.com

@ Summary of the model
MODFLOW is the name that has been given the USGS Modular Three-Dimensional Ground-Water Flow Model. Because of its ability to simulate a wide variety of systems, its extensive publicly available documentation, and its rigorous USGS peer review, MODFLOW has become the worldwide standard ground-water flow model. MODFLOW is used to simulate systems for water supply, containment remediation and mine dewatering. When properly applied, MODFLOW is the recognized standard model used by courts, regulatory agencies, universities, consultants and industry.

The main objectives in designing MODFLOW were to produce a program that can be readily modified, is simple to use and maintain, can be executed on a variety of computers with minimal changes, and has the ability to manage the large data sets required when running large problems. The MODFLOW report includes detailed explanations of physical and mathematical concepts on which the model is based and an explanation of how those concepts were incorporated in the modular structure of the computer program. The modular structure of MODFLOW consists of a Main Program and a series of highly-independent subroutines called modules. The modules are grouped in packages. Each package deals with a specific feature of the hydrologic system which is to be simulated such as flow from rivers or flow into drains or with a specific method of solving linear equations which describe the flow system such as the Strongly Implicit Procedure or Preconditioned Conjugate Gradient. The division of MODFLOW into modules permits the user to examine specific hydrologic features of the model independently. This also facilitates development of additional capabilities because new modules or packages can be added to the program without modifying the existing ones. The input/output system of MODFLOW was designed for optimal flexibility.

Ground-water flow within the aquifer is simulated in MODFLOW using a block-centered finite-difference approach. Layers can be simulated as confined, unconfined, or a combination of both. Flows from external stresses such as flow to wells, areal recharge, evapotranspiration, flow to drains, and flow through riverbeds can also be simulated.

MODFLOW is most appropriate in those situations where a relatively precise understanding of the flow system is needed to make a decision. MODFLOW was developed using the finite-difference method. The finite-difference method permits a physical explanation of the concepts used in construction of the model. Therefore, MODFLOW is easily learned and modified to represent more complex features of the flow system.

Model name: MT3D
Website: http://www.epa.gov/ada/csmos/models/mt3d.html

@ Summary of the model
MT3D is a 3D solute transport model for simulation of advection, dispersion, and chemical reactions of dissolved constituents in ground-water systems. The model uses a modular structure similar to that implemented in MODFLOW. The modular structure makes it possible to independently simulate advection, dispersion, sink/source mixing, and chemical reactions without reserving computer memory space for unused options. MT3D uses a mixed Eulerian-Lagrangian approach to solve the three-dimensional advective-dispersive-reactive equation, in three basic options: the method of characteristics (MOC), the modified method of characteristics (MMOC), and a hybrid of these two methods (HMOC). This approach combines the strength of the MOC for eliminating numerical dispersion with the computational efficiency of the MMOC. The availability of both MOC and MMOC options, and their selective use based on an automatic adaptive procedure under the HMOC option, make MT3D uniquely suitable for a wide range of field problems. MT3D is intended for use with any block-centered finite-difference flow model such as MODFLOW and is based on the assumption that changes in the concentration field will not measurably affect the flow field. This allows the user to independently construct and calibrate a flow model. MT3D retrieves the hydraulic heads and the various flow and source/sink terms saved by the flow model, automatically incorporating the specified hydrologic boundary conditions. Although the MT3D documentation describes the use of MT3D in conjunction with MODFLOW, the transport model can be linked to any other block-centered finite-difference flow model. MT3D can be used to simulate changes in concentration of single-species miscible contaminants in ground-water considering advection, dispersion, and some simple chemical reactions. The chemical reactions included in the model are equilibrium-controlled linear or non-linear sorption and first-order irreversible decay or biodegradation.

Model name: FEFLOW
Website : www.scisoftware.com

@ Summary of the model
FEFLOW (Finite Element Flow) is one of the most sophisticated groundwater modeling packages available. The program provides an advanced 2d and 3D graphically based modeling environment for performing complex groundwater flow, contaminant transport, and heat transport modeling. FEFLOW simulation capabilities include: Fully transient, semi-transient, and steady-state groundwater flow and contaminant transport for saturated and/or unsaturated conditions (2D & 3D), Particle tracking and flow pathlines, Confined and unconfined aquifers including multiple free surfaces, Chemical mass transport, Fluid and solid heat transport, Density-dependent flow, Time-varying, constrained boundary conditions and Time-varying material data.

Model name: ChemStat
Website: www.scisoftware.com

@ Summary of the model
ChemStat is a Windows 95/NT-based program for fast and accurate analysis of ground-water monitoring data at RCRA facilities. Analysis methods in ChemStat comply with 1989 and 1992 US EPA statistical guidance documents (included with the program). ChemStat is not a converted DOS program but is written as a 32-bit Windows 95/NT program from the first line of code. ChemStat is fast and powerful. The number of samples and number of wells are limited only by available computer memory. ChemStat has been tested on data sets with up to 5,000 samples. ChemStat includes easy-to-use Windows 95 interface features such as context sensitive on-line help, Tip of the Day screen on startup, recent file lists, customizable printing with print-preview, spin buttons for numerical data entry, and more. Parameters and wells for analysis are selected from a drop-down list box on the main window tool bar. ChemStat is not a database, but is designed specifically for statistical analysis of data. Data is imported from tab-delimited ASCII text files. Utilities to convert data from GRITS/STAT and ChemPoint formats are included. Importing accommodates filtering by start and end date, facility ID, and parameter suite. ChemStat also accepts comparison levels such as MCL for each parameter.

Model name: RBCA Tier 2 Analyzer
Website: www.scisoftware.com

@ Summary of the model
The RBCA Tier 2 Analyzer is a two-dimensional groundwater model with a comprehensive selection of contaminant transport simulation capabilities including single or multiple species sequential decay reactions such as reductive dechlorination of PCE instantaneous or kinetic-limited BTEX biodegradation with single or multiple electron acceptors and equilibrium or non-equilibrium sorption.

Model name: UTCHEM
Website: http://www.epa.gov/ada/csmos/models/utchem.html

@ Summary of the model
Application: Originally a three-dimensional finite difference model for multiphase flow, transport and chemical flooding, the UTCHEM code has been modified to transform it into a general purpose NAPL simulator. Appropriate physical, chemical and biological process models have been incorporated into the simulator to create a 3D multiphase multi-component model capable of simulating the fate and transport of NAPL's 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 or 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 NAPL's in contaminated aquifers have been incorporated into the simulator. These include multiple organic NAPL phases; the dissolution and/or mobilization of NAPL's 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, cosolvents and other enhancement agents. The biodegredation model includes inhibition, sequential use of electron acceptors, and cometabolism and can be used to model a very general class of bioremediatio processes.

Miscellaneous: Biodegredation capabilities have been added to describe the transformation of organic contaminants from NAPL sources and can accommodate multiple substrates, electron acceptors and biological species. A new multiphase capillary-pressure 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 for explicitly. Phase saturations and concentrations are solved in a flash routine. An energy balance equation includes heat flow between the reservoir and the over- and under- burden rocks.

Model name: AQUA3D
Website: www.scisoftware.com

@ Summary of the model
AQUA3D is a program developed to solve three-dimensional groundwater flow and transport problems using the Galerkin finite-element method. AQUA3D solves transient groundwater flow with inhomogeneous and anisotropic flow conditions. Boundary conditions may be prescribed nodal head and prescribed flow as a function of time or head-dependent flow. AQUA3D also solves transient transport of contaminants and heat with convection, decay, adsorption and velocity-dependent dispersion. Boundary conditions may be either prescribed nodal concentration (temperature) or prescribed dispersive mass (heat) flux.

Model name: BALANCE
Website: www.scisoftware.com

@ Summary of the model
BALANCE is a USGS computer program for calculating mass transfer for geochemical reactions in ground water. BALANCE is designed to help define and quantify chemical reactions between ground water and minerals. Data required to run BALANCE are: (1) the chemical compositions of two water samples, generally assumed to represent points along a flow path, and (2) the chemical compositions of a set of minerals, organic substances, or gases, which we will call phases, selected as the reactants or products in the system. Implicit in this treatment is the assumption that only these selected phases participate in the chemical reactions that determine the composition of the final water.

Model name: BIOF&T 3-D
Website: www.scisoftware.com

@ Summary of the model
BIOF&T 3-D models biodegradation, flow and transport in the saturated and unsaturated zones in two or three dimensions in heterogeneous, anisotropic porous media or fractured media. BIOF&T allows real world modeling not available in similar packages. Model convection, dispersion, diffusion, adsorption, desorption, and microbial processes based on oxygen-limited, anaerobic, first-order, or Monod-type biodegradation kinetics as well as anaerobic or first-order sequential degradation involving multiple daughter species.

Model name: Bioplume III
Website: www.scisoftware.com

@ Summary of the model
Bioplume III is a two-dimensional, finite difference model for simulating the biodegradation of hydrocarbons in groundwater. The Bioplume III model simulates both aerobic and anaerobic biodegradation processes in addition to advection, dispersion, sorption and ion exchange. Bioplume III simulates the biodegradation of organic contaminants using a number of aerobic and anaerobic electron acceptors: oxygen, nitrate, iron (III), sulfate, and carbon dioxide. Bioplume III is based on the U. S. Geologic Survey (USGS) Method of Characteristics Model (MOC) dated July 1989 (Konikow and Bredehoeft). The Bioplume III code was developed primarily to model the natural attenuation of organic contaminants in groundwater due to the processes of advection, dispersion, sorption and biodegradation. Bioplume III solves the transport equation six times to determine the fate and transport of the hydrocarbons and the electron acceptors/reaction byproducts. For the case where iron (III) is used as an electron acceptor, the model simulates the production and transport of iron (II) or ferrous iron.

Model name: ChemFlux
Website: www.scisoftware.com

@ Summary of the model
ChemFlux is the most powerful and stable finite element contaminant transport modeling software currently available. ChemFlux is a finite element software package characterized by automatic mesh generation, automatic mesh refinement and automatic time-step refinement. The solver offers speed and reduction in convergence problems over other similar software packages. Results of benchmark tests run against MT3D confirm the effectiveness of the solver. ChemFlux is able to provide the same level of accuracy as MT3D in solutions dominated by advection while implementing the irregular geometry benefits of the finite element method. ChemFlux can also import groundwater gradients from the powerful SVFlux groundwater modeling package.

Designed for use by geotechnical/geoenvironmental engineers, hydrogeologists, geological engineers and soil scientists, ChemFlux offers a new level of computing power not currently available. Predicting the movement of contaminant plumes through the processes of advection, diffusion, adsorption and decay is possible.

The ChemFlux design module provides an elegant and simple user interface. Problem geometry and groundwater gradients may be imported from the SVFlux software. ChemFlux modeling is, therefore, fast and allows the soil professional to focus on the model and not the method.

Model name: GFLOW 2000
Website: www.scisoftware.com

@ Summary of the model
GFLOW 2000 is a highly-efficient stepwise groundwater flow modeling system. It is a Windows 95/98/NT program based on the analytic element method. It models steady-state flow in a single heterogeneous aquifer using the Dupuit-Forchheimer assumption. While GFLOW 2000 supports some local transient and three-dimensional flow modeling, it is particularly suitable for modeling regional horizontal flow. To facilitate detailed local flow modeling, GFLOW 2000 supports a MODFLOW-extract option to automatically generate MODFLOW files in a user-defined area with aquifer properties and boundary conditions provided by the GFLOW analytic element model. GFLOW 2000 also supports conjunctive surface water and groundwater modeling using stream networks with calculated baseflow.

Model name: HSSM
Website: www.scisoftware.com

@ Summary of the model
HSSM (Hydrocarbon Spill Screening Model) is a U.S. EPA model which simulates subsurface releases of light nonaqueous phase liquids (LNAPLs). The HSSM model includes separate modules for LNAPL flow through the vadose zone, spreading in the capillary fringe, and transport of chemical constituents of the LNAPL in a water-table aquifer. These modules are based on simplified conceptualizations of the flow and transport phenomena which were used so that the resulting model would be a practical, though approximate tool. Both DOS and Windows interfaces are provided to create input data sets, run the model, and graph the results. HSSM includes the executable, source code and technical support.

Model name: HST3D
Website: www.scisoftware.com

@ Summary of the model
HST3D is a powerful user-friendly interface for HST3D integrated within the Argus Open Numerical Environments (Argus ONE) modeling environment. HST3D allows the user to enter all spatial data, graphically run HST3D, and visualize the results. Argus ONE integrates CAD, GIS, Database, Conceptual Modeling, Geostatistics, Automatic Grid and Mesh Generation, and Scientific Visualization within one comprehensive graphical user interface (GUI). The Heat and Solute Transport Model HST3D simulates ground-water flow and associated heat and solute transport in three dimensions. The HST3D model may be used for analysis of problems such as those related to subsurface-waste injection, landfill leaching, saltwater intrusion, freshwater recharge and recovery, radioactive waste disposal, water geothermal systems, and subsurface energy storage. The Argus ONE GIS and Grid Modules are required to run HST3D. The HST3D GUI is available for free from the U.S. Geological Survey Website.

Model name: Mars 2-D/3-D
Website: www.scisoftware.com

@ Summary of the model
Mars 2-D/3-D, the ultimate multiphase areal remediation simulator model, models flow of water and light nonaqueous phase liquid (LNAPL) and aqueous phase transport of up to five species in ground water with multiple pumping and/or injection wells. MARS is a finite-element model that allows accurate representation of highly-irregular material and physical boundaries in a heterogeneous and anisotropic media.

Model name: MicroFEM
Website: www.scisoftware.com

@ Summary of the model
MicroFEM is a finite-element program for multiple-aquifer steady-state and transient ground water flow modeling. MicroFEM's suite of programs takes you through the whole process of ground water modeling, from the generation of a mesh through the stages of preprocessing, calculation, postprocessing, graphical interpretation and plotting. Confined, semi-confined, phreatic, stratified and leaky multiple-aquifer systems can be simulated with a maximum of 20 aquifers. One of the outstanding features of MicroFEM is the user-friendly interface. Its capacity, speed, flexibility and ease of use have made MicroFEM one of the most widely-used ground water modeling packages in the world. MicroFEM's users are comprised of government agencies, consultants and universities.

Model name: SLAEM / MLAEM Overview
Website: www.scisoftware.com

@ Summary of the model
The AEM family of computer programs, SLAEM, MLAEM/2, and MLAEM, are based on the Analytic Element Method developed by Dr. O.D.L. Strack. For a description of the Analytic Element Method, see "Groundwater Mechanics" by O.D.L. Strack (Prentice-Hall, 1989). The computer programs are intended for modeling regional groundwater flow in systems of confined, unconfined, and leaky aquifers. SLAEM (Single Layer Analytic Element Model) is the single-layer version of the program. MLAEM/2 (Multi Layer Analytic Element Model) can access two layers while the number of layers supported by MLAEM is limited only by hardware. All programs run under Microsoft Windows 95, 98 and NT. The programs are native windows applications and are accessed via a modern and flexible Graphical User Interface (GUI), as well as via a command-line interface. The latter capability makes it easy to drive the program from other programs such as Arc-View, ARC/INFO, and PEST. The programs create files from data entered graphically via the GUI; these files can be read in later. The programs read DXF-files and produce BNA files that may be read by other programs such as SURFER.

Model name: MOC
Website: www.scisoftware.com

@ Summary of the model
MOC simulates 2-D solute transport in flowing ground water. MOC is both general and flexible in that it can be applied to a wide range of problem types. MOC is applicable for one- or two-dimensional problems involving steady-state or transient flow. MOC computes changes in concentration over time caused by the processes of convective transport, hydrodynamic dispersion, and mixing (or dilution) from fluid sources. MOC assumes that gradients of fluid density, viscosity and temperature do not affect the velocity distribution. However, the aquifer may be heterogeneous and/or anisotropic. MOC is based on a rectangular, block-centered, finite-difference grid. It allows the specification of injection or withdrawal wells and of spatially-varying diffuse recharge or discharge, saturated thickness, transmissivity, boundary conditions and initial heads and concentrations. MOC incorporates first-order irreversible rate-reaction; reversible equilibrium controlled sorption with linear, Freundlich, or Langmuir isotherms; and reversible equilibrium-controlled ion exchange for monovalent or divalent ions.

Model name: MOCDENSE
Website: www.scisoftware.com
Website: www.water.usgs.gov/software/mocdense.html

@ Summary of the model
MOCDENSE is a modified version of the ground-water flow and solute-transport model of Konikow and Bredehoeft which was designed to simulate the transport and dispersion of a single solute that does not affect the fluid density. This modified version of MOCDENSE simulates the flow in a cross-sectional plane rather than in an areal plane. Because the problem of interest involves variable density, the modified model solves for fluid pressure rather than hydraulic head in the flow equation; the solution to the flow equation is still obtained using a finite-difference method. Solute transport is simulated in MOCDENSE with the method of characteristics as in the original model. Density is considered to be a function of the concentration of one of the constituents.

Model name: SHARP
Website: http://water.usgs.gov/software/sharp.html

@ Summary of the model
When the width of the freshwater-saltwater transition zone is small relative to the thickness of the aquifer, it can be assumed that freshwater and saltwater are separated by a sharp interface. The sharp interface modeling approach, in conjunction with vertical integration of the aquifer flow equations, facilitates regional scale studies of coastal areas. This approach does not give information concerning the nature of the transition zone but does reproduce the regional flow dynamics of the system and the response of the interface to applied stresses. SHARP is a quasi-three-dimensional, numerical model that solves finite-difference approximations of the equations for coupled freshwater and saltwater flow separated by a sharp interface in layered coastal aquifer systems. The model is quasi-three dimensional because each aquifer is represented by a layer in which flow is assumed to be horizontal.

Model name: MOC3D
Website: http://water.usgs.gov/nrp/gwsoftware/moc3d/moc3d.html

@ Summary of the model
This model simulates three-dimensional solute transport in flowing ground water. The model computes changes in concentration of a single dissolved chemical constituent over time that are caused by advective transport, hydrodynamic dispersion (including both mechanical dispersion and diffusion), mixing (or dilution) from fluid sources, and mathematically simple chemical reactions (including linear sorption, which is represented by a retardation factor, and decay). The model can also simulate ground-water age transport and the effects of double porosity and zero-order growth/loss.

Model name: 2DFATMIC
Website: http://www.epa.gov/ada/csmos/models/2dfatmic.html

@ Summary of the model
FATMIC 2D (2DFATMIC) simulates subsurface flow, transport, and fate of contaminants which are undergoing chemical and/or biological tranformations. The model is applicable to transient conditions in both saturated and unsaturated zones. 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. This model can almost eliminate spurious oscillation, numerical dispersion, and peak clipping due to advective transport.

Model name: 3DFATMIC
Website: http://www.epa.gov/ada/csmos/models/3dfatmic.html

@ Summary of the model
FATMIC 3D (3DFATMIC) simulates subsurface flow, transport, and fate of contaminants which are undergoing chemical and/or biological transformations. The model is applicable to transient conditions in both saturated and unsaturated zones. 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. This model can almost eliminate spurious oscillation, numerical dispersion, and peak clipping due to advective transport.

Model name: FEMWATER/LEWASTE
Website: www.epa.gov
Website: http://www.cee.odu.edu/model/femwater.php

@ Summary of the model
Three-Dimensional Finite Element Model of Water Flow Through Saturated-Unsaturated Media (3DFEMWATER) and Three-Dimensional Lagrangian-Eulerian Finite Element Model of Waste Transport Through Saturated-Unsaturated Media (3DLEWASTE) are related and can be used together to model flow and transport in three dimensional, variably-saturated porous media under transient conditions with multiple distributed and point sources/sinks. These models can be used to apply the assimilative capacity criterion to development of wellhead protection areas, as each U.S. state is required to do under the 1986 Amendments to the Safe Drinking Water Act. The complexity of 3DFEMWATER/3DLEWASTE numerical models requires that they be used by experienced numerical modelers with strong background in hydrogeology. 3DFEMWATER is designed to simulate the movement of moisture through variably saturated porous media. 3DLEWASTE is designed to simulate solute transport through variably saturated porous media.

Model name: BIOSLURP
Website: http://www.scisoftware.com/products/bioslurp_overview/bioslurp_overview.html

@ Summary of the model
BIOSLURP is an areal finite-element model to simulate three-phase (water, oil and gas) flow and multicomponent transport in ground water in the unsaturated zone gas phase. Currently the most advanced model of its kind, BIOSLURP can be used to optimize the recovery of LNAPL, water, and gas by minimizing NAPL entrapment in the saturated/unsaturated zones, and simultaneously simulate multispecies aqueous and gas phase transport in unconfined aquifers. BIOSLURP can also simulate coupled flow of water and LNAPL with a static atmospheric gas phase, as well as the transport in ground water. BIOSLURP simulates heterogeneous, anisotropic porous media or fractured media. It allows use of isoparametric elements to accurately represent material and physical/hydraulic boundaries. BIOSLURP can be used to design NAPL recovery and hydraulic containment systems for the free phase hydrocarbon plume and dissolved phase plume under complex hydrogeological conditions. Bioslurping (vacuum enhanced recovery) increases gradients in water and oil potentials with minimal fluctuations in the fluid tables and thus helps to reduce volume of residual product and enhance free product recovery.

Model name: MS-VMS
Website: http://www.scisoftware.com/products/msvms_overview/msvms_overview.html

@ Summary of the model
MS-VMS is a comprehensive MODFLOW-based ground-water flow and contaminant transport modeling system. We believe that MS-VMS sets the highest standard for ground-water modeling in the industry. The USGS modular ground-water flow model, MODFLOW, is the most widely-used ground-water flow model in the world. But, in its original form, MODFLOW has certain limitations and cannot be used to simulate some complex problems encountered regularly by modelers, hydrogeologists, and engineers in the field. MS-VMS overcomes these limitations.

Sea Water

• Sea Water Model includes

1. SLROSM
2. OILMAP
3. SED3D
4. AQUASEA

Model name: SLROSM
Website: http://www.slross.com/modeling/modelingcontent.php

@ Summary of the model
SLROSM. The oil spill behavior model developed at SL Ross is one of the most comprehensive available and has been "ground-truthed" on a number of experimental and real offshore spills. The model describes the trajectory and behavior of marine oil spills as a function of type, size, oil properties and prevailing environmental conditions. The model calculates the results of the weathering spill processes of spreading, evaporation, natural dispersion and emulsification at regular intervals and provides data on the spill's viscosity, density, water content, volume-on-surface, areas, dispersed and evaporated volumes, pour point and thickness.
The model has the unique capability of describing the fate and behavior of oil in unusual situations such as spills involving waxy, high-pour-point oils, spills of heavy oils that submerge or sink beneath the water surface, and spills in broken ice conditions. Another unique aspect of the SL Ross model is the ability to accurately model the effect of different spill sources, such as surface spills, blowouts and subsea pipelines. The model can also simulate countermeasures operations like in situ burning, dispersant application and skimming.

Model name: OILMAP
Website: http://www.aims.gov.au/pages/research/oil-map/oil-map01.html

@ Summary of the model
OILMAP is a user-friendly, PC based oil spill model system suitable for use in oil spill response and contingency planning. It requires no knowledge of oil spill modelling. OILMAP provides rapid prediction of the movement of spilled oil and uses simple graphical procedures for quickly entering wind data and specifying a spill scenario. The system incorporates an embedded Geographic Information System (GIS) for storing any type of geographically referenced data and can be used to display model predictions in relation to important or sensitive resources.
Numerous options are available within OILMAP which allow the system to be customised to meet the user's needs. All have been rigorously tested in both actual spill events and spill drills.

The OILMAP software was developed by Applied Science Associates in the USA and commissioned by a consortium of companies, including Exxon, Chevron and Mobil Oil. To setup such a system in the Australian/Asian/Pacific region, AIMS provides a complete project management function.

In the last two years we have joined forces with Dr Graeme Hubbert of Global Environmental Modelling Services (GEMS) to supply our clients with the best available capability in oil spill prediction and contingency planning. Traditionally, oil spill models have used predicted wind forecasts in conjunction with historic current data. Whilst historic data may be suitable for training and contingency planning, it has no application to real time modelling. This collaboration has involved linking the GEMS 3D ocean model "GCOM3D" (formally known as "OILTRAK") with the OILMAP system. GCOM3D is a fully three-dimensional hydrodynamic model with proven capability of predicting near surface ocean currents around the continental shelf. GCOM3D focuses on predicting the particle trajectory path produced by the surface ocean currents during an oil spill. Embedded tidal and bathymetric databases are used in conjunction with forecast wind data to then provide a rapid forecast of the surface ocean currents. This hydrodynamic data is then used directly by OILMAP to drive the oil spill models.

It is important to note that this is a fully automated system. The operator is required only to enter wind data and define the area or boundary in which the modelling is to take place. These tasks can be performed in a matter of minutes using the OILMAP user-friendly graphics interface. The OILMAP/GCOM3D system is completely relocatable within the geographic area. A typical installation includes bathymetric and tidal databases and coastal map for the entire geographic area, the extent of which is defined by the client.
The final OILMAP/GCOM3D system provides a complete and comprehensive management tool for reducing the economic and environmental damage associated with an oil-spill and enables better planning of oil industry support facilities.

Model name: SED3D
Website: www.epa.gov

@ Summary of the model
Model name: SED3D
Summary of the model
The Three-Dimensional Numerical Model of Hydrodynamics and Sediment Transport in Lakes and Estuaries (SED3D) simulates the flow and sediment transport in lakes, estuaries, harbors, and coastal waters. SED3D is a dynamic modeling system that can be used to simulate the flow and sediment transport in various water bodies under the forcing of winds, tides, freshwater inflows, and density gradients with the influence of the Coriolis acceleration, complex bathymetry, and shoreline geometry. This model can be run in a three-dimensional mode, a two-dimensional vertically integrated 'x-y' mode, or a two-dimensional 'x-z' mode. Given proper boundary and initial conditions, the model can compute the time-dependent, three-dimensional velocity components (u,v,w), temperature (T), salinity (S), and suspended sediment concentration (c) in the Cartesian and vertically stretched grid system (x,y,s). The model contains a free-surface, as opposed to a rigid-lid, with proper boundary conditions for velocity, temperature, salinity, and sediment. A simplified second-order closure model of turbulent transport is used to compute the vertical eddy viscosity and diffusivity contained in the model equations.

Model name: AQUASEA
Website: www.scisoftware.com

@ Summary of the model
AQUASEA is a software package developed to solve the shallow water flow and transport equations using the Galerkin finite element method. AQUASEA was first developed in 1983 to solve two-dimensional problems, and since 1992, it has been continuously upgraded and tested worldwide on the most difficult modeling problems. The latest development of AQUASEA is a version which runs in Windows 95/98/2000 or Windows NT. It has been specifically configured and compiled to provide maximum efficiency in model set up and fast model run times. The Windows environment provides not only a multi-platform capability but also an assured industry standard user interface for future developments. The AQUASEA model consists of the following two models: hydrodynamic flow model and transport-dispersion model. The AQUASEA flow model can simulate water level variations and flows in response to various forcing functions in lakes, estuaries, bays and coastal areas. The water levels and flows are approximated in a numerical finite element grid and calculated on the basis of information on the bathymetry, bed resistance coefficients, wind field and boundary conditions. The AQUASEA transport-dispersion model simulates the spreading of a substance in the environment under the influence of the fluid flow and the existing dispersion processes. The substance may be a pollutant of any kind, conservative or non-conservative, inorganic or organic salt, heat suspended sediment, dissolved oxygen, inorganic phosphorus, nitrogen and other water quality parameters.

Air

• Air Model includes

1. ALOHA
2. Ausplume
3. CALRoads View
4. PLUMES
5. ISC-AERMOD
6. ISC-AERMOD View
7. Screen View
8. AirQUIS
9. AFTOX

Model name: ALOHA
Website : http://response.restoration.noaa.gov/cameo/aloha.html

@ Summary of the model
ALOHA (Areal Locations of Hazardous Atmospheres) is a computer program that uses information you provide it, along with physical property data from its extensive chemical library, to predict how a hazardous gas cloud might disperse in the atmosphere after an accidental chemical release. ALOHA can predict rates of chemical release from broken gas pipes, leaking tanks, and evaporating puddles, and can model the dispersion of both neutrally-buoyant and heavier-than-air gases. ALOHA can display a "footprint" plot of the area downwind of a release where concentrations may exceed a user-set threshold level. It also displays plots of source strength (release rate), concentration, and dose over time. ALOHA accepts weather data transmitted from portable monitoring stations, and can plot footprints on electronic maps displayed in a companion mapping application, MARPLOT, as in the example at right. ALOHA originated as an in-house tool used by NOAA's emergency responders. It was originally based on a simple model--a continuous point source with a Gaussian plume distribution (Turner, 1970). It has evolved over the years into a tool used for response, planning, training, and academic purposes. It is distributed worldwide to thousands of users in government and industry. Because ALOHA is intended for use during hazardous chemical emergencies, it was designed to meet the following criteria:

- Operates on common computers. ALOHA runs quickly on small computers (IBM-compatible or Macintosh) that are easily transportable and affordable for most users. Its algorithms represent a compromise between accuracy and speed; it has been designed to produce good results quickly enough to be of use to responders.
- ALOHA runs on Apple Macintosh computers and in Microsoft Windows (Version 3.0 or later). It requires at least 1 megabyte of random access memory (RAM) and a hard drive.

Model name: Ausplume
Website: www.scisoftware.com

@ Summary of the model
The software was developed to provide a fast, PC-based, user-friendly modelling package capable of accurately predicting the ground level concentration of pollutants or odours emitted from a variety of sources such as: elevated point sources (industrial stacks) area sources (sewage treatment works, anaerobic lagoons, tips or contaminated sites) volume sources ('fugitive' emissions from buildings, wind-blown dust from storage piles). Consequently, AUSPLUME predicts concentrations for a number of time intervals. AUSPLUME also estimates particle deposition onto the ground and the effects of terrain on the plume. Since buildings influence the dispersion of the majority of industrial emissions to the air, AUSPLUME simulates the effects of building wakes on the dispersion of elevated plumes. Data requirements : Characteristics of the source, Meteorological data, Receptor locations, Topographical data (ground elevations of both the source and receptors) and Other AUSPLUME runs under Windows 95/98/NT or Window 3.x, running on both Pentium and 486 PCs.

Model name: CALRoads View
Website : www.weblakes.com/CALRoads/CALRoadsFeatures.html
Website: www.lakes-environmental.com

@ Summary of the model
CALRoads View is an Air Dispersion Modeling Package for predicting air quality impacts of pollutants near roadways, CALRoads View features three mobile source dispersion models: CALINE4, CAL3QHC, CAL3QHCR. CALINE4: Predicts air concentrations of carbon monoxide (CO), Nitrogen Dioxide (NO2), and suspended particles near roadways. Options are available for modeling near intersections, parking lots, elevated or depressed freeways, and canyons CAL3QHC: Estimates total air pollutant concentrations (CO or PM) near highways from both moving and idling vehicles. This model also estimates the length of queues formed idling vehicles at signalized intersections. CAL3QHCR: An enhanced version of CAL3QHCR, this model can process up to a year of hourly meteorological data and vehicular emissions, traffic volume, and signalization (ETS) data for each hour of a week.

Model name: PLUMES
Website: www.epa.gov

@ Summary of the model
PLUMES includes two initial dilution plume models (RSB and UM) and a model interface manager for preparing common input and running the models. Two farfield algorithms are automatically initiated beyond the zone of initial dilution. PLUMES also incorporates the flow classification scheme of the Cornell Mixing Zone Models (CORMIX) with recommendations for model usage, thereby providing a linkage between the systems. PLUMES models are intended for use with plumes discharged to marine and some freshwater bodies. Both buoyant and dense plumes, single sources, and many diffuser outfall configurations can be modeled.

Model name: ISC-AERMOD
Website: www.scisoftware.com

@ Summary of the model
ISC-AERMOD View is a complete and powerful Windows air dispersion modeling system which seamlessly incorporates three popular U.S. EPA models into one interface: ISCST3, AERMOD and ISC PRIME. The Industrial Source Complex - Short Term regulatory air dispersion model (ISCST3) is a Gaussian plume model and is widely used to assess pollution concentration and/or deposition flux on receptors from a wide variety of sources. AERMOD is the next generation air dispersion model which incorporates planetary boundary layer concepts. The Industrial Source Complex - Plume RIse Model Enhancements (ISC-PRIME) dispersion model is similar to the ISCST3 model but contains enhanced building downwash analysis.

Model name: ISC-AERMOD View
Website: http://www.air-dispersion-model.com/html/air-quality.html

@ Summary of the model
ISC-AERMOD View is a complete and powerful Windows air dispersion modeling system which seamlessly incorporates three popular U.S. EPA air quality and air dispersion models into one interface: ISCST3, AERMOD and ISC PRIME.

The Industrial Source Complex - Short Term regulatory air dispersion model (ISCST3) is a Gaussian plume model and is widely used to assess pollution concentration and/or deposition flux on receptors from a wide variety of sources.

AERMOD is the next generation air dispersion model which incorporates planetary boundary layer concepts.
The Industrial Source Complex - Plume RIse Model Enhancements (ISC-PRIME) dispersion model is similar to the ISCST3 model but contains enhanced building downwash analysis.

Model name: Screen View
Website: http://www.air-dispersion-model.com/html/air-dispersion.html

@ Summary of the model
Screen View is a Windows interface to the U.S. EPA screening model, SCREEN3. Screen View allows you to obtain ground-level pollutant concentration estimates for a single source. You can use Screen View, for example, to analyze the worst case scenarios for air pollutant concentrations.

Screen View estimates maximum ground-level concentrations and the distance to the maximum. It incorporates the effects of building downwash on the maximum concentrations for both the near wake and far wake regions. Screen View also estimates concentrations due to inversion breakup and shoreline fumigation. It can terrain including distances out to 100 km for long-range transport. Screen View can examine a full calculate the maximum concentration at any number of user-specified distances in flat or elevated simple range of meteorological conditions including all stability classes and wind speeds to find maximum impacts.

Model name: AirQUIS
Website: http://www.nilu.no/avd/imis/airquis.html

@ Summary of the model
The AirQUIS system was developed by institutions dealing with air pollution, information technology and geographical information systems (GIS). The combination of on-line data collection, statistical evaluations and numerical modelling enable the user to obtain information, carry out forecasting and future planning of air quality. The system can be used for monitoring and to estimate environmental impacts from planned measures to reduce air pollution.

Model name: AFTOX
Website: http://www.breeze-software.com/content/software/haz/aftox.htm

@ Summary of the model
AFTOX, a Gaussian puff/plume model that simulates the atmospheric dispersion of neutrally buoyant chemical releases. The model was developed by the U.S. Air Force, and has been thoroughly evaluated and refined against more than 240 test cases and field studies. The model is intended for estimating concentrations downwind of accidental chemical releases, where the dispersing plume has the same density as air.
AFTOX can model the downwind concentration from several source types, including point, area, and liquid spill sources. For each source type, the release can be continuous, finite, or instantaneous in duration. If a liquid spill is being modeled, AFTOX can calculate the evaporation rate from the pool using one of three evaporation models (Vossler, Shell, or Clewell evaporation models) in addition to providing the downwind plume concentrations.
For each release, AFTOX assumes the plume distribution is Gaussian in the downwind and crosswind directions. The model uses Pasquill-Gifford dispersion coefficients, with modifications to account for a user-specified averaging time.

Soil

• Soil Model includes

1. CHEMFLO
2. NAPL Simulator
3. AIRFLOW/SVE
4. Disturbed WEPP
5. X-DRAIN
6. PRZM3
7. RITZ
8. SESOIL
9. P3DAIR

Model name: CHEMFLO
Website: http://www.epa.gov/ada/csmos/models/chemflo.html

@ Summary of the model
CHEMFLO enables users to simulate water movement and chemical transport in unsaturated soils by solving the Richards equation (water) and the convection-dispersion equation (chemicals). Results can be displayed in graphical form for:

- water content, matric force potential, driving force, conductivity, and flux density of water versus distance or time.
- concentration and flux density of a chemical as a function of distance or time. cumulative fluxes of water and chemical and total mass of chemical in the soil as a function of time.
Results also can be output in tabular form.

Model name: NAPL Simulator
Website: http://www.epa.gov/ada/csmos/models/napl.html

@ Summary of the model
NAPL Simulator conducts a simulation of the contamination of soils and aquifers which results from the release of organic liquids commonly referred to as Non-Aqueous Phase Liquids (NAPLS). 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 3-phase k-S-P sub-model accommodates capillary and fluid on a Hermite collocation finite element discretization. The simulator provides an accurate entrapment hysteresis. NAPL dissolution and volatilization are accounted for through rate-limited mass transfer sub-models. The numerical solution is based solution of a coupled set of non-linear partial differential equations that are generated by combining fundamental balance equations with constitutive thermodynamic relationships.

Model name: AIRFLOW/SVE
Website: http://www.flowpath.com/software/airsve/airsve.html

@ Summary of the model
AIRFLOW/SVE is a finite-difference numerical model for simulating vapor flow and multi-component vapor transport in unsaturated, heterogeneous and anisotropic soil. The model calculates radially symmetrical, steady-state vapor flow towards an extraction well and accounts for time-variant depletion of non-aqueous phase liquid (NAPL) organic contaminants. It contains a fully-integrated graphical interface, allowing the user to easily design the model, run simulations, display results, and produce report quality output; all within the same seamless environment. AIRFLOW/SVE overcomes the major limitations of other commercial SVE models by considering vapor flow through heterogeneous and anisotropic soil with variable water contents, and by implementing a rigorous treatment of the partitioning processes which occur between the soil, aqueous, NAPL and vapor phases. In addition: Volumetric flow rates in the well are calculated directly by the model for a specified well vacuum pressure. Mass transfer between NAPL, water, soil and vapor can be represented as kinetically-controlled or as an equilibrium process. Different types of equilibrium sorption isotherms can be simulated. Differential NAPL mass depletion is simulated, with the more volatile compounds extracted first. Pressures and flow velocities recalculated as the NAPL mass is depleted. With AIRFLOW/SVE, the efficient algorithms and robust numerical methods assure conservation of mass for the vapor and NAPL for large simulations with several different chemical components.

Model name: Disturbed WEPP
Website: http://forest.moscowfsl.wsu.edu/fswepp/docs/distweppdoc.html

@ Summary of the model
Disturbed WEPP is one in a series of the U.S.D.A. Forest Service's Internet-based computer programs based on the Agricultural Research Service's Water Erosion Prediction Project (WEPP) model. Disturbed WEPP is designed to predict runoff and sediment yield from young and old undisturbed forests, prescribed and wild forest fires skid trails and harvested forests, rangelands with short grass, tall grass, and shrub plant communities and any condition with little soil disturbance (no tillage) but a definable amount of soil residue cover (such as parks, pastures, notill agriculture). Disturbed WEPP is not intended for tilled agricultural conditions (use USDA-ARS templates (WEPP, 1999)) and sites where soil is severely disturbed or compacted, such as roads and trails (use WEPP:Road), construction sites, heavily-used playgrounds or trampled rangelands, Disturbed WEPP allows the user to specify the characteristics of the site in terms of climate, soil texture, local topography, plant community and surface residue cover.

Model name: X-DRAIN
Website: http://forest.moscowfsl.wsu.edu/fswepp/docs/xdrain2doc.html#topofpage

@ Summary of the model
X-DRAIN is one in a series of the U.S.D.A. Forest Service's Internet-based computer programs based on the Agricultural Research Service and others' Water Erosion Prediction Project (WEPP) model. X-DRAIN is designed to estimate sediment yield from roads, landings, skid trails, and foot trails as affected by climate, soil, local topography, and transportation system characteristics. X-DRAIN can be used to determine optimum cross drain spacing for existing or planned roads, and for developing and supporting recommendations concerning road construction, reconstruction, realignment, closure, obliteration, or mitigation efforts based on sediment yield.

Model name: PRZM3
Website: www.epa.gov

@ Summary of the model
The PRZM3 model is the most recent version of a modeling system that links two subordinate models--PRZM and VADOFT--in order to predict pesticide transport and transformation down through the crop root and unsaturated zone. PRZM is a one-dimensional, finite-difference model that accounts for pesticide and nitrogen fate in the crop root zone. PRZM-3 includes modeling capabilities for such phenomena as soil temperature simulation, volatilization and vapor phase transport in soils, irrigation simulation, microbial transformation, and a method of characteristics (MOC) algorithm to eliminate numerical dispersion. PRZM is capable of simulating transport and transformation of the parent compound and as many as two daughter species. VADOFT is a one-dimensional, finite-element code that solves the Richard's equation for flow in the unsaturated zone. The user may make use of constitutive relationships between pressure, water content, and hydraulic conductivity to solve the flow equations. VADOFT may also simulate the fate of two parent and two daughter products. The PRZM and VADOFT codes are linked together with the aid of a flexible execution supervisor that allows the user to build loading models that are tailored to site-specific situations. In order to perform probability-based exposure assessments, the code is also equipped with a Monte Carlo pre- and post-processor.

The PRZM3 model system with documentation is available for microcomputer (DOS) systems. Enhancements to Release 3.0 include algorithms that enable modeling of nitrogen cycle soil kinetic processes with the ability to track nitrogen discharges from a septic tank into the soil environment and movement to groundwater. Additional enhancements enable better simulation of physiochemical processes, increased flexibility in representing agronomic practices, and improved post-processing and data interpretation aids.

Model name: RITZ
Website: http://www.epa.gov/ada/csmos/models/ritz.html

@ Summary of the model
RITZ is a screening level model for simulation of unsaturated zone flow and transport of oily wastes during land treatment. RITZ was developed to help decision makers systematically estimate the movement and fate of hazardous chemicals during land treatment of oily wastes. The model considers the downward movement of the pollutant with the soil solution, volatilization, and loss to the atmosphere, and degradation. The model incorporates the influence of oil upon the transport and fate of the pollutant. The model is based on a series of closed-form analytical equations. The model assumes that waste material is uniformly mixed in the plow zone, that the oil in the waste material is immobile, and that the soil properties are uniform from the soil surface to the bottom of the treatment zone. Furthermore, the flux of water is considered uniform throughout the treatment site and throughout time, and hydrodynamic dispersion is insignificant and can be neglected. The partitioning of pollutant between the liquid, soil, vapor, and oil phases is described by linear equilibrium isotherms. Degradation of pollutant and oil is described as a first-order process.

RITZ is menu-driven and facilitates interactive data entry. The program produces graphical and tabular output. RITZ is distributed on a DOS-formatted disk containing source code and executable image. The documentation includes installation instructions and the EPA user's manual.

Model name: SESOIL
Website: http://www.scisoftware.com/products/sesoil_overview/sesoil_overview.html

@ Summary of the model
SESOIL is a seasonal compartment model which simulates long-term pollutant fate and migration in the unsaturated soil zone. SESOIL describes the following components of a user-specified soil column which extends from the ground surface to the ground-water table.
- Hydrologic cycle of the unsaturated soil zone.
- Pollutant concentrations and masses in water, soil, and air phases.
- Pollutant migration to ground water.
- Pollutant volatilization at the ground surface.
- Pollutant transport in washload due to surface runoff and erosion at the ground surface.
SESOIL estimates all of the above components on a monthly basis for up to 999 years of simulation time. It can be used to estimate the average concentrations in ground water. The soil column may be composed of up to four layers, each layer having different soil properties which affect the pollutant fate. In addition, each soil layer may be subdivided into a maximum of 10 sublayers in order to provide enhanced resolution of pollutant fate and migration in the soil column. The following pollutant fate processes are accounted for: Volatilization, Adsorption, Cation Exchange, Biodegradation, Hydrolysis and Complexation.

Model name: P3DAIR
Website: http://www.scisoftware.com/products/p3dair_overview/p3dair_overview.html

@ Summary of the model
P3DAIR can be used to simulate the movement of air and the advective transport of vapor in unsaturated soils. P3DAIR is particularly useful for delineating contaminant capture zones and evaluating the effectiveness of vapor extraction wells. P3DAIR is recommended for use with MODAIR which is a MODFLOW-based software package for modeling air flow in the unsaturated zone. P3DAIR uses the input files and pressure solution of MODAIR. However, it can be readily modified to work in conjunction with any other block-centered finite-difference flow model. P3DAIR generates output files containing: x,y,z coordinates at different travel times along the path of each individual particle; x,y,z coordinates of all the particles at a user-specified time; and initial and final positions of particles captured by various sinks or sources in the case of backward tracking. P3DAIR produces output files of pathlines of individual particles, positions of displacement fronts of capture zones at desired time, and distribution of captured particles.

แบบจำลองประเมินความเสี่ยง

Surface Water

• Surface Water Risk Assessment Model includes

1. EXAMS
2. AquaDyn

Model name: EXAMS
Website: www.epa.gov
Website: www.cee.odu.edu/model/exams_windows.php

@ Summary of the model
The Exposure Analysis Modeling System, first published in 1982 (EPA-600/3-82- 023), provides interactive computer software for formulating aquatic ecosystem models and rapidly evaluating the fate, transport, and exposure concentrations of synthetic organic chemicals - pesticides, industrial materials, and leachates from disposal sites.

EXAMS contains an integrated Database Management System (DBMS) specifically designed for storage and management of project databases required by the software. User interaction is provided by a full-featured Command Line Interface (CLI), context- sensitive help menus, an on-line data dictionary and CLI users' guide, and plotting capabilities for review of output data. EXAMS provides 20 output tables that document the input data sets and provide integrated results summaries for aid in ecological risk assessments.

EXAMS' core is a set of process modules that link fundamental chemical properties to the limnological parameters that control the kinetics of fate and transport in aquatic systems. The chemical properties are measurable by conventional laboratory methods; most are required under various regulatory authorities. EXAMS limnological data are composed of elements historically of interest to aquatic scientists world-wide, so generation of suitable environmental data sets can generally be accomplished with minimal project- specific field investigations.

EXAMS provides facilities for long-term (steady-state) analysis of chronic chemical discharges, initial-value approaches for study of short-term chemical releases, and full kinetic simulations that allow for monthly variation in mean climatological parameters and alteration of chemical loadings on daily time scales. EXAMS has been written in generalized (N- dimensional) form in its implementation of algorithms for representing spatial detail and chemical degradation pathways. The complexity of the environmental description and the number of chemicals is fully user-controlled.

Model name: AquaDyn
Website: www.scisoftware.com

@ Summary of the model
AquaDyn is a powerful and easy-to-use hydrodynamic simulation model essential for water resources engineering studies, risk assessment, and impact studies. AquaDyn allows the complete description and analysis of hydrodynamic conditions (e.g., flow rates and water levels) of open channels such as rivers, lakes, or estuaries. Engineers, specialists, and decision-makers can use the specialized modules of the AquaDyn simulation package to predict impacts on water flow conditions. For instance, AquaDyn provides a reliable way to forecast the consequences of different activities such as dredging or building dikes, bridges piers, and embankments. AquaDyn can be used to model steady and unsteady flows in supercritical as well as subcritical conditions and therefore permits the user to take into account and study the effects of weirs, contractions, and tidal waves.

Ground Water

• Surface Water Risk Assessment Model includes

1. VLEACH
2. PATRIOT

Model name: VLEACH
Website: http://www.contaminatedland.co.uk/risk-ass.htm
Website: http://www.epa.gov/ada/csmos/models/vleach.html

@ Summary of the model
VLEACH is a one-dimensional, finite difference model for making preliminary assessments of the effects on ground water from the leaching of volatile, sorbed contaminants through the vadose zone. The program models four main processes: liquid-phase advection, solid-phase sorption, vapor-phase diffusion, and three-phase equilibration. In an individual run, VLEACH can simulate leaching in a number of distinct polygons, which may differ in terms of soil properties, recharge rates, depth of water, or initial conditions. Modeling results in an overall, area-weighted assessment of ground-water impact.

Model name: PATRIOT
Website: www.epa.gov

@ Summary of the model
Pesticide Assessment Tool for Rating Investigations of Transport (PATRIOT) provides rapid analyses of ground water vulnerability to pesticides on a regional, state, or local level. PATRIOT assesses ground water vulnerability by quantifying pesticide leaching potential in terms of pesticide mass transported to the water table. It integrates a tool that enables analysis of pesticide leaching potential with data required for area-specific analysis anywhere in the U.S. PATRIOT is composed of:
1) a pesticide fate and transport model (PRZM2),
2) a comprehensive database,
3) an interface that facilitates database exploration,
4) a directed sequence of interactions that guide the user in providing necessary information to perform alternative model analyses, and
5) user-selected methods for summarizing and visualizing results.
Users are expected to be State personnel charged with developing pesticide management plans as well as other regulatory and resource management institutions

Sea Water

• Sea Water Model includes

Air

• Air Model includes

1. SEVEX View
2. CAP88-PC
3. COMPLY
4. SLAB View
   

Model name: SEVEX View
Website: http://www.weblakes.com/lakesvx1.html

@ Summary of the model
SEVEX View is software designed to estimate risks zones around hazardous materials handling and storage facilities like chemical activities, railway marshalling yards, ports area or pipe-line terminals. SEVEX View computes all the aspects and consequences of accidental releases of hazardous materials (toxic or flammable) through a set of coherent scientific models: The source term module (SEVEX-SOURCE) that includes calculations of: gaseous, liquid and two-phase flow rates, jet dispersion, aerosol vaporization, pool formation and evaporation, dense gas dispersion, unconfined vapor cloud explosion (UVCE) and fireball thermal radiation (BLEVE). For quick assessment purposes allowing to design the most relevant scenarios and situations, the SEVEX-SOURCE module can be coupled to simple Gaussian dispersion model. The 3-D meso-meteorological module (SEVEX-MESO) is a 3-D numerical model solving the simplified Navier-Stokes equations for the wind flow in a vorticity mode. This model takes into account the topography and the main surface characteristics such as roughness length, heat and radiation transfer between the surface and the atmosphere which extends up to 2000 m. Computations are made for different synoptic wind speeds and directions during cloudy days and clear nights. Those situations have been chosen because they lead to the worst dispersion conditions.

The 3-D dispersion module (SEVEX-TOXIC) is a Lagrangian dispersion model. It simulates passive transportation and dispersion of particles of toxic or irritating substances at a rate and in a state given by the SEVEX-SOURCE module. The wind fields and turbulence characteristics are taken from the SEVEX-MESO module. These different modules are linked together and implemented into a user-friendly interface. Starting from a source description (or accidental release scenario) deduced from a safety analysis, SEVEX View enables the user to produce maps directly usable by emergency planning teams. These maps show various danger zones considering toxicity, overpressure and heat effects. Three levels of danger are taken into account : temporary diseases, permanent injuries out door and danger indoor. SEVEX View maps show also where no danger is expected. This information enables the user to define clearly the behavior to adopt facing the danger: no change in behavior, avoiding exposure advised, self-confinement or evacuation.

The outputs of SEVEX View are compiled into a database of potential accident maps showing accidental scenario information (substance, effects, danger to public, meteorological conditions, etc.), realistic mapping of risk zones corresponding to defined thresholds and behavior to adopt. In case of an emergency, this so-called "SEVEX Atlas" provides an immediate answer or anticipated decision about the behavior to adopt and the instructions to enforce in each danger zone. Such anticipated decisions are the only way to avoid the chaos of misleading orders. Indeed SEVEX View prevention policy is to be prepared for the worst "realistic" situations. This will lead to conservative decisions for better conditions. SEVEX View integrates in each level of the analysis the inherent uncertainties of emergency situations and builds up the most suitable emergency plan on the basis of the very few certainties available. SEVEX limits the problem to realistic danger extent and leads to an effective emergency response.

Model name: CAP88-PC
Website: www.epa.gov/radiation/assessment

@ Summary of the model
CAP88-PC version 1.0 is a personal computer software system used for calculating dose and risk from annual average releases of radionuclide to the air. CAP88-PC version 1.0 is a DOS based software and is approved for demonstrating compliance with 40 CFR 61.93 (a). CAP88-PC version 2.0 is a Windows version of CAP88-PC. Version 2.0 includes some minor changes compared to the DOS version. These changes include:
addition of decay chains for six radionuclides
- Strontium Chain (SR-90/Y-90)
- Zirconium Chain (ZR-95/NB-95)
- Ruthenium 103 Chain (RU-103/RH-103M)
- Ruthenium 106 Chain (RU-106/RH-106)
- Cerium Chain (CE-144/PR-144)
- Plutonium (PU-241/AM-241)
corrects a minor error in the Uranium decay chain; corrects a typographical error in the concentration reports.

Model name: COMPLY
Website: www.epa.gov/radiation/assessment

@ Summary of the model
A computerized screening tool for evaluating radiation exposure from atmospheric releases of radionuclides. May be used for demonstrating compliance with some EPA and Nuclear Regulatory Commission regulations. COMPLY calculates the effective dose equivalent (ede) from radionuclides released from stacks and vents. Atmospheric concentrations are estimated using a Gaussian plume model and equations that account for building wake effects.

Model name: SLAB View
Website: www.lakes-environmental.com

@ Summary of the model
The best tool to predict hazardous zone and potential impacts of accidental releases. Ideal for EPA's Risk Management Plan (RMP) and to analyze emissions from accidental releases of toxic gases. SLAB View can model continuous, finite duration, and instantaneous releases from four types of sources: a ground-level evaporating pool, an elevated horizontal jet, a stack or elevated vertical jet, and a ground-based instantaneous release. Some features that will save you a huge amount of time and hassle include:
- SLAB View is an integrated modeling environment: intuitive data input, model run, and full featured post-processing with automatic gridding and contour plotting of your results. The graphical output can be directly pasted into your favorite Windows word processor.
- SLAB View comes with an extensive database of toxic materials that will save you time and make your modeling project easier. You can also easily add other chemicals to the database

Soil

• Soil Model includes

Health

• Health Model includes

1. PRESTO
2. IRAP-h
3. RISKIND
4. TRIM
5. CAMEO

Model name: PRESTO
Website: www.epa.gov/radiation/assessment

@ Summary of the model
PRESTO (Prediction of Radiological Effects Due to Shallow Trench Operations) is a computer model for evaluating radiation exposure from contaminated soil layers, including waste disposal, soil cleanup, agricultural land application, and land reclamation.
The models are designed to calculate the maximum annual committed effective dose to a critical population group and cumulative fatal health effects and genetic effects to the general population in several scenarios: near surface disposal trench containing low-level radioactive waste and/or naturally occurring or accelerator produced radioactive material (NARM) residual radionuclides remaining in soil layers after cleanup agricultural land application of technologically enhanced naturally occurring radioactive materials (TENORM) waste stripped land reclamation with applied TENORM waste. The models simulate the transport of radionuclides in air, surface water, and groundwater pathways, and evaluate exposures through ingestion, inhalation, immersion and external exposure pathways.

Model name: IRAP-h
Website: www.lakes-environmental.com

@ Summary of the model
IRAP-h View fully implements the latest U.S. EPA guidance for evaluating risk from emission sources: the 1998 U.S. EPA - OSW Human Health Risk Assessment Protocol (HHRAP). IRAP-h View is a user friendly graphical interface, with help wizards, user tips, and more, allowing all experience levels of risk assessors, trial burn planners, permit writers, and toxicologists to readily produce expert results and reports in a fraction of the time and cost traditionally required. IRAP-h View easily guides the inexperienced and experienced user alike step-by-step through completing a risk assessment according to the latest U.S. EPA recommended exposure scenarios; including specialty risk exposure pathways such as the Breast Milk Equation and Lead Exposure.

Model name: RISKIND
Website: http://www.techtransfer.anl.gov/highlights/8-1/transport.html

@ Summary of the model
The RISKIND computer code analyzes radiological consequences and health risks to individuals and populations resulting from exposure associated with the transportation of spent nuclear fuel and other radioactive materials. The code addresses specific areas of concern to individuals or populations and incorporates many user-friendly features. RISKCHEM, a similar code, is being developed to estimate consequences and health effects resulting from accidents involving the transportation of hazardous chemicals.
Argonne's comprehensive approach is the U.S. Department of Energy (DOE) standard for transportation risk assessment, and DOE has used it to make major waste management decisions. The use of RISKIND is expanding, and a user-friendly Windows interface has been added to it to enable interested parties to address specific concerns.

Model name: TRIM
Website: http://eetd.lbl.gov/ied/ERA/

@ Summary of the model
The Office of Air Quality Planning and Standards (OAQPS) of the U.S. Environmental Protection Agency (EPA) has the responsibility for the hazardous and criteria air pollutant programs described by sections 112 and 108 of the Clean Air Act (CAA). In response to aspects of these programs that require evaluation of health risks and environmental effects associated with air pollutant exposures, as well as scientific recommendations of the National Academy of Sciences (NRC, 1994), the Presidential/Congressional Commission on Risk Assessment and Risk Management (CRARM 1997), and Agency guidelines and policies, the OAQPS recognized the need for improved fate and transport, exposure, and risk modeling tools.

To support evaluations with a scientifically sound, flexible and user-friendly methodology, the Total Risk Integrated Methodology (TRIM), a time series modeling system with multimedia capabilities for assessing human health and ecological risks from hazardous and riteria air pollutants, is being developed. The TRIM design includes three modules: the Environmental Fate, Transport, and Ecological Exposure module, TRIM.FaTE; the human Exposure-Event module, TRIM.Expo; and, the Risk Characterization module, TRIM.Risk.

The first TRIM module to be developed, TRIM.FaTE, is a spatial compartmental mass balance model that describes the movement and transformation of pollutants over time, through a user-defined, bounded system that includes both biotic and abiotic compartments. TRIM.FaTE, the emphasis for which is air pollutants for which non-inhalation exposures are important, generates both media concentrations relevant to human pollutant exposures and exposure estimates relevant to ecological risk assessment. The Exposure-Event module, TRIM.Expo, can receive input from TRIM.FaTE or from air quality models or monitoring data. In TRIM.Expo, human exposures are evaluated by tracking population groups referred to as "cohorts" and their inhalation and ingestion through time and space.

Model name: CAMEO
Website: http://response.restoration.noaa.gov/cameo/cameo.html

@ Summary of the model
The CAMEO (Computer-Aided Management of Emergency Operations) program is an integrated set of software modules jointly developed by NOAA and EPA. It's designed to help first responders and emergency planners plan for and quickly respond to chemical accidents. Rapid actions by firefighters, police, and other emergency personnel are often hampered by a lack of accurate information about the substances spilled and the safe actions to be taken to protect responders and the public. CAMEO is intended to be a solution to this problem.
CAMEO is available for both Windows and Macintosh computers. It includes a database of hazardous chemicals.
- MARPLOT, an electronic mapping program.
- ALOHA, a computer model that predicts the movement of chemical gases in the atmosphere.
CAMEO's chemical database contains response recommendations for about 6,000 chemicals. It also contains 80,000 chemical synonyms and identification numbers, which you can quickly search to identify unknown substances during an incident. Once a chemical is identified, CAMEO provides firefighting and spill response recommendations, physical properties, health hazards, and first aid guidance.

แบบประยุกต์ใช้งาน

Environmental Model Applications

1. RECOVERY: A Contaminated Sediment-Water Interaction Model
2. Evaluation of a Gaussian-modified dispersion model for atmospheric release from the Marcoule nuclear site
3. Modelling the contribution of different sources of sulphur to atmospheric deposition in the United Kingdom
4. Testing the CORMIX model using thermal plume data from four Maryland power plants
5.TEMMS: an integrated package for modelling and mapping urban traffic emissions and air quality
6. Revisions of the ADIOS oil spill model
7. A salt-transport model within a land-surface scheme for studies of salinisation in irrigated areas
8. Measurement and modelling of pollutant emissions from Hong Kong
9. Modelling the urban water cycle
10. Application of ADIFOR for air pollution model sensitivity studies
11. A simple semi-empirical model for predicting missing carbon monoxide concentrations
12. Modeling nitric oxide emissions from biosolid amended soils
13. Modeling surface-mediated renoxification of the atmosphere via reaction of gaseous nitric oxide with deposited nitric acid
14. Summer ozone episodes in the Greater Madrid area. Analyzing the ozone response to abatement strategies by modelling
15. An on-road motor vehicle emissions inventory for Denver: an efficient alternative to modeling>
16. A Study of Vadose Zone Transport Model VLEACH
17. Monte Carlo Simulation for a Groundwater Mixing Model in Soil Remediation of Tetrachloroethylene
18. Modelling of physical and reactive processes during biodegradation of a hydrocarbon plume under transient groundwater flow conditions
19. A stochastic multi-channel model for solute transport--analysis of tracer tests in fractured rock
20. Modeling in situ ozonation for the remediation of nonvolatile PAH-contaminated unsaturated soils
21. Humic acid enhanced remediation of an emplaced diesel source in groundwater
22. Predicting natural attenuation of xylene in groundwater using a numerical model
23. Multi-component reactive transport modeling of natural attenuation of an acid groundwater plume at a uranium mill tailings site
24. Modelling the closure-related geochemical evolution of groundwater at a former uranium mine

RECOVERY: A Contaminated Sediment-Water Interaction Model
Carlos E. Ruiz
CEERD-EP-W, U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS 39180-6199, USA
Nadim M. Aziz
Department of Civil Engineering, 110 Lowry Hall, Clemson University, Clemson, SC 29634-0911, USA
Paul R. Schroeder
CEERD-EP-S, U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS 39180-6199, USA

Abstract
This paper describes the U.S. Army Corps of Engineers screening-level water quality model (RECOVERY version 3.0) for assessing long-term impacts of contaminated bottom sediments on surface waters. The model couples contaminant interaction between the water column and the bottom sediment, as well as between contaminated and clean bottom sediments. The analysis is intended primarily for organic contaminants with the assumption that the overlying water column is well mixed vertically. The contaminant is assumed to follow linear, reversible, equilibrium sorption and first-order decay kinetics. The system is physically represented as a well-mixed water column (i.e., zero-dimensional) underlain by a vertically-stratified sediment column (i.e., one-dimensional). The sediment is well-mixed horizontally but segmented vertically into a well-mixed surface (active) layer and deep sediment. The deep sediment is segmented into variably contaminated and clean sediment regions. Processes incorporated in the model are sorption, decay, volatilization, burial, resuspension, settling, bioturbation, and pore-water diffusion. The solution couples contaminant mass balance in the water column and in the mixed sediment layer along with diffusion in the deep sediment layers. The model was verified against laboratory and field data, as well as against an analytical solution for the water and mixed sediment layers. These comparisons indicate that the model can be used as an assessment tool for evaluating remediation alternatives for contaminated bottom sediments.

Keywords : contaminated sediments, modeling, natural attenuation, RECOVERY, sediment quality, water quality
Article ID : 354534

Evaluation of a Gaussian-modified dispersion model for atmospheric release from the Marcoule nuclear site
O. Vauquelin Laboratoire de M?canique des Fluides et Energ?tique, Universit? de Valenciennes, le mont Houy, F-59306 Valenciennes, France
F. L?vy
COGEMA, Service de Protection contre les Rayonnements, F-30206 Bagnols-sur-C?ze Cedex, France

Abstract
This paper presents a mathematical model of local pollutant dispersion designed to compute the concentration field above and around the Marcoule nuclear site. The model is based on integrating the classical turbulent diffusion equation, corrected (prior to integration) by experimental wind tunnel data obtained for a scaled-down model of the site. The computed results are compared with full-scale experimental observations at Marcoule in the case of neutral atmosphere. A comparison with the standard Gaussian model is also made. Finally, a critical analysis of the model is presented.
Keywords : modified Gaussian model, in situ measurements, model evaluation
Article ID : 327624

Abstract
In order to understand relationships between sources and receptors of atmospheric deposition, computer models must be used. This paper describes a Lagrangian acid deposition model that represents emissions of trace species across Northern Europe. The chemistry of sulphur dioxide, dimethyl sulphide and hydrogen sulphide is represented and the model tested against estimates of UK wet and dry deposition. Mean UK wet and dry deposition for the period 1992-1994 was 206 and 145 ktonne S yr-1, respectively. The model predicted wet and dry deposition of 222 and 166 ktonne S yr-1, in good agreement with measurements. The model has been used to examine the sources of deposited S to the UK. For a base year of 1992, 86% of the UK's SO2 emissions are exported. The S deposition attributable from mainland European sources was 36% of the UK total S deposition, in good agreement with other UK models but this differs substantially from the calculations of the EMEP model. Natural sources of S deposition from planktonic emissions of dimethyl sulphide, biological emissions of hydrogen sulphide and non-eruptive volcanic emissions of sulphur dioxide contributed approximately 1% of the modelled UK S deposition, of which 95% originated from dimethyl sulphide. The explicit chemical scheme for dimethyl sulphide incorporated into the model showed that 24% of the resultant deposited S was methane sulphonic acid. Boundary conditions of the model were tested and it was found that initialisation of sulphur dioxide and sulphate concentrations to representative ambient conditions had a very small effect. The modelled contribution of UK and European sources to UK S deposition was approximately 40 and 60%, respectively, showing the dramatic change arising from projected UK SO2 emissions in 2010.

Article ID : 327625

Water quality assessment through hydrodynamics and transport
simulation in the S. Gilla lagoon, Italy
A. Atzeni
Dipartimento di Ingegneria del Territorio, Universit? di Cagliari, Piazza d'Armi, 4, I-09123 Cagliari, Italy E-mail: balzano@ idraca.unica.it
A. Balzano
Dipartimento di Ingegneria del Territorio, Universit? di Cagliari, Piazza d'Armi, 4, I-09123 Cagliari, Italy E-mail: balzano@ idraca.unica.it
G. Lai
Dipartimento di Ingegneria del Territorio, Universit? di Cagliari, Piazza d'Armi, 4, I-09123 Cagliari, Italy E-mail: balzano@ idraca.unica.it

Abstract
The paper describes the study of the hydrodynamic and transport features of the S. Gilla lagoon in Sardinia, Italy. The study, aimed at assessing the environmental quality of the water body, involved extensive use of numerical models based on the shallow water equations, thus enabling to simulate a number of different situations of practical interest. Based on field data, six meteorological and hydrologic patterns were recognised which were assumed as representative of the various conditions occurring in the four seasons. Typical winter conditions proved effective for the water refreshment, while the other seasonal patterns induced a stronger internal mixing. Thus, unfavourable salinity distributions with respect to the fish farm activities, which are carried out in the water body, were obtained with the winter pattern, whereas, on the other hand, a higher dilution of pollutants discharged by the river inflows was achieved. In general, between dominant winds, southeast winds proved more effective in forcing internal mixing than northwest winds. Two flood events with quite different return periods were also simulated, in order to estimate the extent of the inundated areas and the salinity depletion. The consequent salinity recovery was simulated both in natural conditions and with the discharge of salt sea water into the lagoon to accelerate the salinity re-equilibrium.
Keywords : hydrodynamics, lagoon, pollutant, salinity, shallow water, transport
Article ID : 327587
http://www.kluweronline.com/issn/1420-2026/contents

Testing the CORMIX model using thermal plume data from four Maryland power plants
S. P. Schreiner, T. A. Krebs, D. E. Strebel and A. Brindley
Versar, Inc., 9200 Rumsey Road, Columbia, MD 21045, USA

Abstract
Historical thermal plume studies from four Maryland power plants (Calvert Cliffs, Chalk Point, Dickerson, and Wagner) were used to test the realism of the CORnell MIXing Zone Expert System ( ). Test data were from a wide range of challenging discharge environments, including a large freshwater river (Potomac), a narrow tidal estuary (Patuxent), a wide tidal estuary (Chesapeake Bay), and a wind-driven tidal estuary (Baltimore Harbor). Historical case studies were simulated, and results were compared qualitatively and quantitatively with historical measurements. Qualitative results show that the model performed optimally for simple discharges into large basins such as Chesapeake Bay. For complex discharges and complex ambient environments, the model often mixed plumes too rapidly, resulting in smaller modeled plumes that were cooler than the measured plumes. The mixing model also could not account for the re-entrainment of effluent from previous tidal cycles. Sensitivity results show that sensitivity is often dependent on model run time and discontinuities in the flow classification scheme. Users of the model need to be aware of these limitations in applying the model to complex situations. results should be used with caution in evaluating the effects of a discharge and only in conjunction with information from the field.

Author Keywords : Mixing zones; Thermal plume; ; Power plants; River; Estuary; Sensitivity analysis; Hydrodynamic model
Environmental Modelling & Software Volume 17, Issue 3, 2002, Pages 321-331

TEMMS: an integrated package for modelling and mapping urban traffic emissions and air quality
Anil Namdeo, Gordon Mitchell , and Richard Dixon
The School of Geography, University of Leeds, Leeds LS2 9JT, UK

Abstract
The Traffic Emission Modelling and Mapping Suite (TEMMS) is a program designed to provide detailed estimates of vehicle emissions on urban road networks, and so act as a precursor to urban air quality modelling. TEMMS is a module of the "Quantifiable City", a more extensive model designed to address questions relevant to urban sustainability. Within the Quantifiable City model, TEMMS interfaces with SATURN, a traffic assignment model, and the Airviro or ADMS-Urban pollutant dispersion models, to calculate spatially defined pollutant concentrations for given traffic, meteorological and stationary source emission inputs. TEMMS also contains an integral model, ROADFAC, which calculates emissions of gases and particulates from vehicles using SATURN traffic or vehicle count data. TEMMS integrates these models via a database exchanger, the MapInfo geographic information system, and a custom-built Windows-based graphical user interface, allowing modelling and mapping of link-based vehicle flow and emissions, and grid-based air quality. TEMMS applications include emission and air quality mapping, evaluation of associated transport policies and scenarios, and preparation of inputs to other (e.g., epidemiological) models. Within this context, TEMMS has generated considerable interest from potential end-users in Local Authorities and air quality management support services. Validation of the integrated model is discussed, and an example application of TEMMS to a large UK city presented.

Author Keywords : Urban transport; Traffic modelling; Emission modelling; Dispersion modelling; Air quality; SATURN; ROADFAC; ADMS-Urban; Airviro
Environmental Modelling & Software Volume 17, Issue 2, 2002, Pages 177-188

Revisions of the ADIOS oil spill model
William Lehr , , Robert Jones, Mary Evans, Debra Simecek-Beatty and Roy Overstreet
Hazardous Materials Response Division, National Oceanic and Atmospheric Administration, Seattle, WA 98115, USA

Abstract
For several years, the National Oceanic and Atmospheric Administration Hazardous Materials Response Division (NOAA/HAZMAT) has been using and distributing the computer software package called ADIOS(TM) (Automated Data Inquiry for Oil Spills) to aid responders in oil spill cleanup. ADIOS forecasts the weathering processes and characteristics of oil slicks. Based on new research results and analysis since the first version was released, a major update revises and improves previous algorithms, plus adds new modules for other weathering processes and for spill cleanup strategies. The weathering processes included in the new version, called ADIOS2, are spreading, evaporation, dispersion, sedimentation, and emulsification. The user cleanup options are dispersants, in-situ burning, and skimming. Different types of release scenarios can be simulated and the user is allowed to enter ranges for selected input variables with the resulting uncertainty displayed in the model output.

Author Keywords : Oil spill; Oil weathering; Spill cleanup; Pollution modeling; Oil slick
Environmental Modelling & Software Volume 17, Issue 2, 2002, Pages 189-197

A salt-transport model within a land-surface scheme for studies of salinisation in irrigated areas
Peng Xu , , a and Yaping Shaob
a School of Mathematics, The University of New South Wales, Sydney, NSW, Australia
b Department of Physics and Materials Science, City University of Hong Kong, Hong Kong

Abstract
Modelling solute transport in an unsaturated zone (vadose) depends very much on the simulation of soil moisture and moisture fluxes, which are strongly influenced by precipitation, evapotranspiration, surface runoff and land-surface properties. To provide good approximations of soil moisture and moisture fluxes, a model capable of simulating land-surface processes is required. In this study, a salt-transport model is developed within the framework of a land-surface model that has detailed treatment of relevant land- surface processes. This coupled model is then applied to investigate the impact of irrigation water on land salinisation in a rice growing area.

Author Keywords : Salt transport; Vadose zone; Salinity; Land-surface modelling; Surface-soil hydrology
Environmental Modelling & Software Volume 17, Issue 1, 2002, Pages 39-49

Measurement and modelling of pollutant emissions from Hong Kong
J. N. Carras , , M. Cope, W. Lilley and D. J. Williams
CSIRO Energy Technology, PO Box 136, N Ryde, NSW, 1670, Australia

Abstract
During November 1997 a detailed airborne investigation of air pollution in the Hong Kong region was undertaken. The airborne investigation formed part of a larger study funded by the Hong Kong Environmental Protection Department (EPD) and included the development of a state of the art numerical air quality modelling system to simulate air pollution in the Hong Kong region.
The system consisted of a numerical weather prediction module, a prognostic air-chemistry/transport model, an emissions inventory system and a Graphical User Interface for display of results and preparation of simulations. The purpose of the airborne investigations was to provide data on the fluxes of selected pollutants arising from or entering the Hong Kong airshed as a check on the inventory. In addition the aircraft was to provide data on other pollutants of interest particularly with respect to the formation of photochemical smog.
This paper describes the inventory data obtained from the aircraft and makes comparisons between the predictions of the model and the aircraft data for one of the days when the aircraft was able to be used to estimate the total fluxes of NMHC and NOx from the study area.

Author Keywords : Aircraft plume data; Air quality modelling; Inventory validation; Urban air pollution; Plume tracking
Environmental Modelling & Software Volume 17, Issue 1, 2002, Pages 87-94

Modelling the urban water cycle
V. G. Mitchell (a)(b) , R. G. Meinb (c) and T. A. McMahonc (d)
a) CSIRO Building Construction and Engineering, PO Box 56, Highett, Vic 3190, Australia
b) Dept of Civil Engineering, PO Box 60, Monash University, Vic 3800, Australia
c) Cooperative Research Centre for Catchment Hydrology, PO Box 60, Monash University, Vic 3800, Australia
d) Dept of Civil and Environmental Engineering, University of Melbourne, Parkville, Vic 3010, Australia

Abstract
Current urban water management practices aim to remove stormwater and wastewater efficiently from urban areas. An alternative approach is to consider stormwater and wastewater as a potential resource substitute for a portion of the water imported via the reticulated supply system. A holistic view of urban water resources provides the framework for the evaluation of the demand for water supply, the availability of stormwater and wastewater, and the interactions between them. The water balance model (Aquacycle) developed in this study represents water flows through the urban water supply, stormwater, and wastewater systems. Its daily time step provides temporal distribution of the flows, and enables comparison of the different components of the urban water demand. Aquacycle was tested using data from the Woden Valley urban catchment in Canberra, Australia and found able to satisfactorily replicate its water supply, stormwater and wastewater flows.

Author Keywords : Stormwater; Wastewater; Water supply; Reuse; Urban water balance model
Environmental Modelling and Software Volume 16, Issue 7, November 2001, Pages 615-629

Application of ADIFOR for air pollution model sensitivity studies
Shan He , a, b, Gregory R. Carmichaela, b, c, Adrian Sandua, Brian Hotchkissa and Valeriu Damian-Iordachea
a Center for Global and Regional Environmental Research, University of Iowa, Iowa, IA 52240, USA
b Department of Civil and Environmental Engineering, University of Iowa, Iowa, IA 52240, USA
c Department of Chemical and Biochemical Engineering, University of Iowa, Iowa, IA 52240, USA

Abstract
Typical computational methods of sensitivity analysis are discussed. Automatic differentiation addresses the need for computing derivatives of large codes accurately, regardless of the complexity of the model. Automatic differentiation in FORTRAN (ADIFOR) is a source transformation technique that accepts FORTRAN coded program for the computation of a function and generates portable FORTRAN code for the computation of the derivatives of that function. ADIFOR is introduced and applied to a comprehensive atmospheric chemistry/transport/radiative-transfer model to study the sensitivity of photochemical ozone production with respect to aerosol. The modeling results indicate that aerosol interaction with ozone may be as important as NOx and non-methane hydrocarbon (NMHC) emissions in determining ozone production. The presence of scattering and/or absorbing aerosols in the atmosphere can cause significant differences in calculated ozone levels. Normalized sensitivity coefficients show that ozone and other photochemical oxidants are most sensitive to the aerosol single scattering albedo, which determines the scattering efficiency of the aerosol. ADIFOR is demonstrated to be an effective tool for sensitivity analysis in air pollution modeling.

Author Keywords : Sensitivity analysis; Automatic differentiation; ADIFOR; Photochemical oxidant cycle; Aerosol; Ozone
Environmental Modelling & Software Volume 15, Issues 6-7, September 2000, Pages 549-557

A simple semi-empirical model for predicting missing carbon monoxide concentrations
Kim N. Dirks (a), Murray D. Johns (a), John E. Hay (a) and Andrew P. Sturman (b)
a) University of Auckland, Private Bag 92019, Auckland, New Zealand
b) University of Canterbury, Private Bag 4800, Christchurch, New Zealand

Abstract
Carbon monoxide monitoring using continuous samplers is carried out in most major urban centres in the world and generally forms the basis for air quality assessments. Such assessments become less reliable as the proportion of data missing due to equipment failure and periods of calibration increases. This paper presents a semi-empirical model for the prediction of atmospheric carbon monoxide concentrations near roads for the purpose of interpolating missing data without the need for any traffic or emissions information. The model produces reliable predictions while remaining computationally simple by being site-specifically optimized. The model was developed for, and evaluated at, both a suburban site and an inner city site in Hamilton, New Zealand. Model performance statistics were found to be significantly better than other simple methods of interpolation with little additional computational complexity.

Author Keywords: Carbon monoxide; Urban air quality; Empirical modeling; Interpolation; Missing data
Atmospheric Environment Volume 36, Issues 39-40, December 2002, Pages 5953-5959

Modeling nitric oxide emissions from biosolid amended soils
Paul A. Roelle (a), Viney P. Aneja (a), Rohit Mathur (b), Jeff Vukovich (b) and Jeffrey Peirce (c)
a) Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695-8208, USA
b) North Carolina Supercomputing Center, PO Box 12889, 3021 Cornwallis Road, Research Triangle Park, NC, 27709-2889, USA
c) Department of Civil and Environmental Engineering, Duke University, Raleigh, NC 27708, USA

Abstract
Utilizing a state-of-the-art mobile laboratory in conjunction with a dynamic flow-through chamber system, nitric oxide concentrations [NO] were measured and NO fluxes were calculated during the summer, winter and spring of 1999/2000. The field site where these measurements were conducted was an agricultural soil amended with biosolids from a municipal wastewater treatment facility. These NO flux values were then used to assess the impact of including biosolid amended soils as a land-use class in an air quality model. The average NO flux from this biosolid amended soil was found to be exponentially dependent on soil temperature [NO Flux (ng N m-2 s-1)=1.07 exp(0.14 Tsoil); R2=0.81--NO Flux=71.3 ng N m-2 s-1at 30?C]. Comparing this relationship to results of the widely applied biogenic emissions inventory system (BEIS2) model revealed that for this field site, if the BEIS2 model was used, the NO emissions would have been underestimated by a factor of 26. Using this newly developed NO flux algorithm, combined with North Carolina Division of Water Quality statistics on how many biosolid amended acres are permitted per county, county-based NO inventories from these biosolid amended soils were calculated. Results from this study indicate that county-level biogenic NO emissions can increase by as much as 18% when biosolid amended soils are included as a land-use class. The multiscale air quality simulation platform (MAQSIP) was then used to determine differences in ozone (O3) and odd-reactive nitrogen compounds (NOy) between models run with and without the biosolid amended acreages included in the inventory. Results showed that during the daytime, when atmospheric mixing heights are typically at their greatest, any increase in O3 or NOy concentrations predicted by the model were small (<3%). In some locations during late evening/early morning hours, ozone was found to be consumed by as much as 11%.

Author Keywords: Nitric oxide; Air quality modeling; Biogenic emissions; Biosolids; Ozone
Atmospheric Environment Volume 36, Issues 36-37, December 2002, Pages 5687-5696

Modeling surface-mediated renoxification of the atmosphere via reaction of gaseous nitric oxide with deposited nitric acid
Eladio M. Knipping and Donald Dabdub
Department of Mechanical and Aerospace Engineering, University of California at Irvine, Irvine, CA 92697-3975, USA

Abstract
Air quality models consider the formation and deposition of nitric acid (HNO3) on surfaces to be an irreversible sink of atmospheric nitrogen oxides (NOx) and therefore an effective termination step in the ozone formation cycle. However, experimental evidence suggests that the reaction of gaseous nitric oxide with nitric acid on surfaces may convert HNO3 to photochemically active NOx. A first-order simulation of this surface-mediated renoxification process is performed using an air quality model of the South Coast Air Basin of California. Peak ozone concentrations are predicted closer to observed values in regions regularly underpredicted by base case models. In certain regions, ozone predictions are enhanced by as much as ~30 ppb or ~20% compared to the baseline simulation. These results suggest that renoxification processes may be a key to resolving long-standing shortcomings of air quality models, in addition to reconciling [HNO3]/[NOx] ratios in remote regions. This study also illustrates that the surface terrain may play a more active chemical role than hitherto considered in air quality models.

Author Keywords: Renoxification; Surface reaction; Ozone; Deposition; Urban photochemical model
Atmospheric Environment Volume 36, Issues 36-37, December 2002, Pages 5741-5748

Summer ozone episodes in the Greater Madrid area. Analyzing the ozone response
to abatement strategies by modelling
M. Palacios (a), F. Kirchner (b), A. Martilli (b), A. Clappier (b), F. Martin (a) and M. E. Rodriguez (c)
a) Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Departamento de Impacto Ambiental de la Energia, E70.P1.05a, Avda. Complutense, 22, 28040, Madrid, Spain
b) Ecole Polytechnique Federal de Lausanne, Departament de Genie Rural, Laboratoire de Pollution de l'Air, CH-1015, Lausanne, Switzerland
c) Escuela Tecnica Superior de Ingenieros Industriales, Departamento de Ingenieria Quimica Industrial, Jose Gutierrez Abascal, 2, 28006, Madrid, Spain

Abstract
The development of ozone control strategies requires analysing the sensitivity of the dispersion model used to changes in emissions of nitrogen oxides (NOX) and volatile organic compounds. The ozone response to variations in road traffic and total anthropogenic emissions is evaluated for two different summer ozone episodes in the Greater Madrid Area (GMA). This study uses the TVM model and a transport/chemistry module in which different chemical mechanisms (EMEP, RACM) are implemented. The results show that the areas of maximum impact and ozone responses are notably influenced by the different transport and dispersion patterns established in the area. However, the contribution of anthropogenic sources other than road traffic is patent in both episodes. Strategies based only on decreasing road traffic emissions were not sufficient for an effective control of the air quality in the GMA. Moreover, certain discrepancies observed in the predicted trends, as a response to these control strategies posed, reflect the importance of variations in the precursors balance. The ozone production regime associated to these ozone episodes and the sensitivity of the ozone response to changes in this balance has been investigated. A chemical indicator has been used to deepen in that evaluation.

Author Keywords: Air quality; Emissions control; Traffic; Photochemical dispersion modelling; Madrid
Atmospheric Environment Volume 36, Issue 34, November 2002, Pages 5323-5333

An on-road motor vehicle emissions inventory for Denver: an efficient alternative to modeling
Sajal S. Pokharel, Gary A. Bishop and Donald H. Stedman ,
Department of Chemistry and Biochemistry, University of Denver, 2101 E. Wesley Ave., Denver, CO 80208, USA
Received 15 April 2002; accepted 3 August 2002. Available online 17 October 2002.

Abstract
Emission inventories from mobile sources have traditionally been obtained through computational modeling. This method, however, has intrinsic shortcomings in that the factors used incorporate only a limited amount of real-world observations. The agreement between model predictions and measurements has often been poor. Recently, a fuel-based method of obtaining on-road emissions inventories has been developed. This technique calculates emission factors in grams of pollutant per unit of fuel used (kg, gallons or l) from remote sensing measurements. Combining these factors with fuel use data, available from tax records, results in a fuel-based emission inventory. This method for obtaining emission inventories is very economical and an ideal alternative for locations lacking the resources to develop an emissions model. We have used this routine to calculate CO, HC and NO on-road running exhaust emissions inventories for the Denver Metropolitan area during several years when the enhanced I/M program has been in place. These calculations indicate a continually decreasing inventory over the 6 yr study period. The calculations are also compared with results from the recent MOBILE6 model. The modeled inventories are 30-70% higher, 40% lower, and 40-80% higher for CO, HC and NO, respectively.

Author Keywords: Fuel-based emission factor; Mobile sources; Remote sensing; Emission model comparison
Atmospheric Environment Volume 36, Issue 33, November 2002, Pages 5177-5184

A Study of Vadose Zone Transport Model VLEACH
Yue Rong
California Regional Water Quality Control Board -- Los Angeles Region, 320 West 4th Street, Suite 200,
Los Angeles, CA 90013

Abstract
Application of vadose zone transport models has been hampered by lack of model validation. Difficulties to validate vadose zone models using field data not only come from model assumptions that are uncertain to the subsurface transport processes but also from the uncertainties associated with soil contaminants' release time and quantity, soil sampling, sample transport, and analytical procedures. This article first conducts a test of a popularly used vadose zone transport VLEACH by comparing model results with a set of laboratory soil column infiltration and volatilization study data. The comparison shows a close agreement between the VLEACH model results and the laboratory data. Second, the sorption coefficient Kd calculated in VLEACH is compared with field data. The comparison indicates that VLEACH may overestimate the mass leached from soil to groundwater. The article also discusses the selection of the model simulation timestep, the vertical dimension increment, the Courant criterion, and the lower boundary condition using the sensitivity analysis method based on a case study of soil remediation for trichloroethylene. The procedures presented in this paper are important to practical model application and modification. This level of work should be routinely conducted for any new or modified version of vadose zone models.

Author Keywords: timestep, vertical dimension increment, lower boundary condition, trichloroethylene, courant criterion, soil-water partition coefficient
Journal of Soil Contamination Volume 8, Issue 2, March 1999, Pages 217-229

Monte Carlo Simulation for a Groundwater Mixing Model in Soil Remediation of Tetrachloroethylene
Yue Rong (a), Rueen Fang Wang (b) and Rebecca Fang Chou (c)
a) California Regional Water Quality Control Board - Los Angeles Region, 101 Centre Plaza Drive, Monterey Park, CA 91754. Fax: (213) 266-7600; Tel: (213) 266-7604
b) California Regional Water Quality Control Board - Los Angeles Region, 101 Centre Plaza Drive, Monterey Park, CA 91754. Fax: (213) 266-7600; Tel: (213) 266-7533
c) California Regional Water Quality Control Board - Los Angeles Region, 101 Centre Plaza Drive, Monterey Park, CA 91754. Fax: (213) 266-7600; Tel: (213) 266-7607

Abstract
This article applies a commonly used groundwater mixing model in conjunction with a one-dimensional vadose zone transport model, VLEACH, to predict the impact of residual soil concentrations of tetrachloroethylene (PCE) on groundwater quality at a site located in Los Angeles, California, where soil remediation has been completed. Sensitivity analysis and Monte Carlo simulation (MCS) are conducted for the groundwater mixing model. The sensitivity analysis identifies hydraulic conductivity that has significant effect on model predictions. Results of MCS indicate that the probability of groundwater concentration of PCE less than or equal to 1.2 g/l is 95%, at 30 m downgradient from the source area with residual PCE concentration of 550 g/ kg in soil. The results of this article clearly demonstrate that model predictions combined with adequate sensitivity analysis and MCS can provide better information to decision makers than conventional model predictions using single-point average input values.

Author Keywords: VLEACH, volatile organic compounds, sensitivity analysis, vadose zone, aquifer, dispersivity, hydraulic conductivity.
Journal of Soil Contamination Volume 7, Issue 1, January 1998, Pages 87-102

Modelling of physical and reactive processes during biodegradation of a hydrocarbon plume
under transient groundwater flow conditions
H. Prommer (a), D. A. Barry (a) and G. B. Davis (b)
a) Faculty of Civil Engineering and Geosciences, Department of Water Management, Delft University of Technology,
Delft, The Netherlands
b) Centre for Applied Geoscience, University of T?bingen, Germany

Abstract
Numerical experiments of non-reactive and reactive transport were carried out to quantify the influence of a seasonally varying, transient flow field on transport and natural attenuation at a hydrocarbon-contaminated field site. Different numerical schemes for solving advective transport were compared to assess their capability to model low transversal dispersivities in transient flow fields. For the field site, it is shown that vertical plume spreading is largely inhibited, particularly if sorption is taken into account. For the reactive simulations, a biodegradation reaction module for the geochemical transport model PHT3D was developed. Results of the reactive transport simulations show that under the site-specific conditions the temporal variations in groundwater flow do, to a modest extent, affect average biodegradation rates and average total (dissolved) contaminant mass in the aquifer. The model simulations demonstrate that the seasonal variability in groundwater flow only results in significantly enhanced biodegradation rates when a differential sorption of electron donor (toluene) and electron acceptor (sulfate) is assumed.

Author Keywords: Reactive transport; BTEX; Dispersion; Sorption; Simulations; Natural attenuation; MT3DMS; MODFLOW; PHREEQC; PHT3D; Dispersion; Vertical mixing; Transverse mixing
Journal of Contaminant Hydrology Volume 59, Issues 1-2, November 2002, Pages 113-131

A stochastic multi-channel model for solute transport--analysis of
tracer tests in fractured rock
Ivars Neretnieks
Department of Chemical Engineering and Technology, Royal Institute of Technology, 10044 Stockholm, Sweden

Abstract
Some of the basic assumptions of the advection-dispersion model (AD-model) are revisited. This model assumes a continuous mixing along the flowpath similar to Fickian diffusion. This implies that there is a constant dispersion length irrespective of observation distance. This is contrary to most field observations. The properties of an alternative model based on the assumption that individual water packages can retain their identity over long distances are investigated. The latter model is called the multi-channel model (MCh-model). Inherent in the latter model is that if the waters in the different pathways are collected and mixed, the "dispersion length" is proportional to distance. The conditions for when non-mixing between adjacent streams can be assumed are explored.
The MCh- and AD-models are found to have very similar residence time distributions (RTD) for Peclet numbers larger than 3. A generalized relation between flowrate and residence time is developed, including the so-called cubic law and constant aperture assumptions. The two models extrapolate very differently when there is strong matrix interaction. The AD-model could severely underestimate the effluent concentration of a tracer pulse and overestimate the residence time.
The conditions are explored for when in-filling particles in the fracture will not be equilibrated but will act as if there was seemingly a much larger flow wetted surface (FWS). It is found that for strongly sorbing tracers, relatively small particles can act in this way for systems and conditions that are typical of many tracer tests.
The assumption that the tracer residence time found by cautiously injecting a small stream of traced water represents the residence time in the whole fracture is explored. It is found that the traced stream can potentially sample a much larger fraction of the fracture than the ratio between the traced flowrate and the total pumped flowrate.
The MCh-model was used to simulate some recent tracer tests in what is assumed to be a single fracture at the ?sp? Hard rock laboratory in Sweden. Non-sorbing tracers, HTO and Uranin were used to determine the mean residence time and its variance. Laboratory data on diffusion and sorption properties were used to "predict" the RTD of the sorbing tracers. At least 30 times larger FWS or 1000 times larger diffusion or sorption coefficients would be needed to explain the observed BTCs. Some possible reasons for such behavior are also explored.

Author Keywords: Groundwater; Solute transport; Fractures; Modelling
Journal of Contaminant Hydrology Volume 55, Issues 3-4, April 2002, Pages 175-211

Modeling in situ ozonation for the remediation of nonvolatile PAH-contaminated
unsaturated soils
Jeongkon Kim (a) and Heechul Choi (b)
a) Environmental Research Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
b) Department of Environmental Science and Engineering, Kwang-Ju Institute of Science and Technology, 1 Oryong-dong Buk-gu 500-712, Kwang-Ju, South Korea

Abstract
Mathematical models were developed to investigate the characteristics of gaseous ozone transport under various soil conditions and the feasibility of in situ ozone venting for the remediation of unsaturated soils contaminated with phenanthrene. On the basis of assumptions for the mass transfer and reactions of ozone, three approaches were considered: equilibrium, kinetic, and lump models. Water-saturation-dependent reactions of gaseous ozone with soil organic matter (SOM) and phenanthrene were employed. The models were solved numerically by using the finite-difference method, and the model parameters were determined by using the experimental data of Hsu [The use of gaseous ozone to remediate the organic contaminants in the unsaturated soils, PhD Thesis, Michigan State Univ., East Lansing, MI, 1995].
The transport of gas-phase ozone is significantly retarded by ozone consumption due to reactions with SOM and phenanthrene, in addition to dissolution. An operation time of 156 h was required to completely remove phenanthrene in a 5-m natural soil column. In actual situations, however, the operation time is likely to be longer than the ideal time because of unknown factors including heterogeneity of the porous medium and the distribution of SOM and contaminant. The ozone transport front length was found to be very limited (<1 m). The sensitivity analysis indicated that SOM is the single most important factor affecting in situ ozonation for the remediation of unsaturated soil contaminated with phenanthrene. Models were found to be insensitive to the reaction mechanisms of phenathrene with either gas-phase ozone or dissolved ozone. More study is required to quantify the effect of OH formation on the removal of contaminant and on ozone transport in the subsurface.

Author Keywords: Modeling; In situ oxidation; Ozonation; Unsaturated soil; Soil organic matter; Phenanthrene
Journal of Contaminant Hydrology Volume 55, Issues 3-4, April 2002, Pages 261-285

Humic acid enhanced remediation of an emplaced diesel source in groundwater
J. W. Molson (a), E. O. Frind (a), D. R. Van Stempvoort (b) and S. Lesage (b)
a) Department of Earth Sciences, University of Waterloo, Waterloo, ON, Canada N2L 3G1
b) National Water Research Institute, P.O. Box 5050, Burlington, ON, Canada L7R 4A6

Abstract
A pilot scale experiment for humic acid-enhanced remediation of diesel fuel, described in Part 1 of this series, is numerically simulated in three dimensions. Groundwater flow, enhanced solubilization of the diesel source, and reactive transport of the dissolved contaminants and humic acid carrier are solved with a finite element Galerkin approach. The model (BIONAPL) is calibrated by comparing observed and simulated concentrations of seven diesel fuel components (BTEX and methyl-, dimethyl- and trimethylnaphthalene) over a 1500-day monitoring period. Data from supporting bench scale tests were used to estimate contaminant-carrier binding coefficients and to simulate two-site sorption of the carrier to the aquifer sand. The model accurately reproduced the humic acid-induced 10-fold increase in apparent solubility of trimethylnaphthalene. Solubility increases on the order of 2-5 were simulated for methylnaphthalene and dimethylnaphthalene, respectively. Under the experimental and simulated conditions, the residual 500-ml diesel source was almost completely dissolved and degraded within 5 years. Without humic acid flushing, the simulations show complete source dissolution would take about six times longer.

Author Keywords: Groundwater remediation; Modeling; Humic acid; Dissolution; Solubilization; Biodegradation
Journal of Contaminant Hydrology Volume 54, Issues 3-4, February 2002, Pages 277-305

Predicting natural attenuation of xylene in groundwater using a numerical model
Wolfgang Schifer
Interdisciplinary Center for Scientific Computing, University of Heidelberg, Im Neuenheimer Feld 368,
69120 Heidelberg, Germany

Abstract
The aquifer beneath an abandoned refinery in the Lower Rhine area, Germany, was contaminated with a number of different mineral oil products. Groundwater sampling in the area around the former xylene plant revealed that a xylene plume had developed in the underlying groundwater, and moreover, that there is strong evidence for in situ microbial xylene degradation with oxygen, nitrate, sulfate and ferric iron as electron acceptors. In order to prevent further xylene spreading, three pumping wells extracting contaminated water were installed downgradient of the spill zone. The numerical reactive transport code Transport Biochemisty Chemistry (TBC) was applied to this situation to quantify the relation of microbial degradation to xylene removal by the pumping wells. It could be shown that the unamended in situ degradation was an appreciable xylene removal process that contributed to about one-third to the total xylene removal (degradation plus extraction). A further objective of the model application was to predict xylene spreading under regional flow conditions, i.e. without operation of the three pumping wells, to consider the possible effects of natural xylene attenuation. To accomplish this, the model calibrated for the situation with operating wells was transferred to the hydraulic situation of regional flow while retaining the parameters of the biochemical model. It turned out that the xylene plume that is expected to develop downgradient of the source area will be limited to an extension of not more than 1000 m. An interesting feature of the simulations results was that xylene degradation under iron-reducing conditions, which was of minor importance for the situation with operating pumping wells, becomes the dominant degradation mechanism under regional flow conditions. Moreover, iron reduction will be the key process in controlling plume evolution. The model application illustrates that multi-species reactive transport models are needed to adequately transfer reactive processes from one hydraulic situation to another, while single species models are not suited for this predictive task.

Author Keywords: Numerical models; Biodegradation; Xylene; Contaminant transport; Groundwater
Journal of Contaminant Hydrology Volume 52, Issues 1-4, November 2001, Pages 57-83

Multi-component reactive transport modeling of natural attenuation of an acid groundwater plume
at a uranium mill tailings site
Chen Zhu (a), Fang Q. Hu (a) and David S. Burden (b)
a) Old Dominion University, Norfolk, VA 23529, USA
b) U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Ada, OK 74820, USA

Abstract
Natural attenuation of an acidic plume in the aquifer underneath a uranium mill tailings pond in Wyoming, USA was simulated using the multi-component reactive transport code . A one-dimensional model was constructed for the site and the model included advective-dispersive transport, aqueous speciation of 11 components, and precipitation-dissolution of six minerals. Transport simulation was performed for a reclamation scenario in which the source of acidic seepage will be terminated after 5 years and the plume will then be flushed by uncontaminated upgradient groundwater. Simulations show that successive pH buffer reactions with calcite, Al(OH)3(a), and Fe(OH)3(a) create distinct geochemical zones and most reactions occur at the boundaries of geochemical zones. The complex interplay of physical transport processes and chemical reactions produce multiple concentration waves. For SO42- transport, the concentration waves are related to advection-dispersion, and gypsum precipitation and dissolution. Wave speeds from numerical simulations compare well to an analytical solution for wave propagation.

Author Keywords: Geochemical modeling; Contaminant; Transport; Coupled processes
Journal of Contaminant Hydrology Volume 52, Issues 1-4, November 2001, Pages 85-108

Modelling the closure-related geochemical evolution of groundwater at a former uranium mine
J. G. Bain (a), K. U. Mayer (a), D. W. Blowes (a), E. O. Frind (a), J. W. H. Molson (a), R. Kahnt (b) and U. Jenk (b)
a) Department of Earth Sciences, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
b) Wismut GmbH, Jagdsch?nkenstr. 29, 09117 Chemnitz, Germany

Abstract
A newly developed reactive transport model was used to evaluate the potential effects of mine closure on the geochemical evolution in the aquifer downgradient from a mine site. The simulations were conducted for the K?nigstein uranium mine located in Saxony, Germany. During decades of operation, uranium at the former mine site had been extracted by in situ acid leaching of the ore underground, while the mine was maintained in a dewatered condition. One option for decommissioning is to allow the groundwater level to rise to its natural level, flooding the mine workings. As a result, pore water containing high concentrations of dissolved metals, radionuclides, and sulfate may be released. Additional contamination may arise due to the dissolution of minerals contained in the aquifer downgradient of the mine. On the other hand, dissolved metals may be attenuated by reactions within the aquifer. The geochemical processes and interactions involved are highly non-linear and their impact on the quality of the groundwater and surface water downstream of the mine is not always intuitive. The multicomponent reactive transport model MIN3P, which can describe mineral dissolution-precipitation reactions, aqueous complexation, and oxidation-reduction reactions, is shown to be a powerful tool for investigating these processes. The predictive capabilities of the model are, however, limited by the availability of key geochemical parameters such as the presence and quantities of primary and secondary mineral phases. Under these conditions, the model can provide valuable insight by means of sensitivity analyses.

Author Keywords: Mining; Acid mine drainage; Reactive transport modelling; Metal mobility; Trace mineralogy
Journal of Contaminant Hydrology Volume 52, Issues 1-4, November 2001, Pages 109-135

Environmental Risk Assessment Model Applications

1. MCE-RISK: integrating multicriteria evaluation and GIS for risk decision-making in natural hazards
2. Development and verification of a screening model for surface spreading of petroleum

Abstract
During the past two decades there have been a wide range of applications for decision-making linking multicriteria evaluation (MCE) and geographic information systems (GIS). However, limited literature reports the development of MCE-GIS software, and the comparison of various MCE-GIS approaches. This paper introduces an MCE-GIS program called MCE-RISK for risk-based decision-making. It consists of a series of modules for data standardisation, weighting, MCE-GIS methods, and sensitivity analysis. The program incorporates different MCE-GIS methods, including weighted linear combination (WLC), the technique for order preference by similarity to ideal solution (TOPSIS), and compromise programming (CP), enabling comparisons between different methods for the same decision problem to be made. An example of decision-making for determining priority areas for a bushfire hazard reduction burning is examined. After implementing the alternative MCE-GIS methods, and comparing final outputs and the computational difficulty involved in the analysis, WLC is recommended. Some caveats on using MCE-GIS methods are also discussed. Although the development of MCE-RISK and its application reported in this paper are specific to risk-based decision-making in natural hazards, the program can be used for other environmental decision applications, such as environmental impact assessment and land-use planning.

Author Keywords: Risk decision-making; Multicriteria evaluation; GIS; Bushfire; Prescribed burning
Environmental Modelling & Software Volume 16, Issue 4, June 2001, Pages 387-397

Development and verification of a screening model for surface spreading of petroleum
Maged Hussein(a), Minghui Jin(b) and James W. Weaver(c)
a) The Ohio State University, Columbus, OH 43210, USA
b) HydroGeoLogic Inc., Herndon, VA, USA
c) Ecosystem Research Division, National Exposure Research Laboratory, Office of Research and Development, United States Environmental Protection Agency, Athens, GA, USA

Abstract
Overflows and leakage from aboveground storage tanks and pipelines carrying crude oil and petroleum products occur frequently. The spilled hydrocarbons pose environmental threats by contaminating the surrounding soil and the underlying ground water. Predicting the fate and transport of these chemicals is required for environmental risk assessment and for remedial measure design. The present paper discusses the formulation and application of the Oil Surface Flow Screening Model (OILSFSM) for predicting the surface flow of oil by taking into account infiltration and evaporation. Surface flow is simulated using a semi-analytical model based on the lubrication theory approximation of viscous flow. Infiltration is simulated using a version of the Green and Ampt infiltration model, which is modified to account for oil properties. Evaporation of volatile compounds is simulated using a compositional model that accounts for the changes in the fraction of each compound in the spilled oil. The coupling between surface flow, infiltration and evaporation is achieved by incorporating the infiltration and evaporation fluxes into the global continuity equation of the spilled oil. The model was verified against numerical models for infiltration and analytical models for surface flow. The verification study demonstrates the applicability of the model.

Author Keywords: Oil spills; Mathematical models; Volatilization; Petroleum seepage
Journal of Contaminant Hydrology Volume 57, Issues 3-4, August 2002, Pages 281-302