Ground Water Modeling Research
Contaminants in ground water can make their way into drinking water supplies, surface water and indoor air. EPA is supporting region, state and tribal partners at Superfund sites and brownfields to develop new methods to better characterize, monitor and treat the contamination. Researchers are using computer models and new technologies to better understand and forecast the behavior of contaminants in ground water to develop better means for treatment.
- Development of a ground water flow tool as a dominate mechanism for contaminant
- Assessment of the state-of-the-science of chlorinated solvents transformation in ground water
- Development of an advanced ground water transport model for contaminants from multiple sources with potential impacts on multiple drinking water wells or other receptors. The model includes transformation of organic subsurface contaminants, source zones for non-aqueous phase liquids (NAPLs), diffusion of contaminants from low permeability layers, and assessment of natural attenuation of contaminants in the subsurface.
- Field and laboratory research on treatment technologies including permeable reactive barriers, on-site chemical treatment and monitored natural attenuation.
Researchers are also studying vapor intrusion from contaminated ground water into buildings. In order to better understand health risks related to the contaminant vapor, researchers are sampling indoor air, soil, soil gas and vapor movement, and assessing the viability associated with vapor phase transport and biodegradation.
Science Inventory Resources
The Science Inventory is a searchable database of research products primarily from EPA's Office of Research and Development. See: all Science Inventory resources.
- EPA Ground Water Issue: Ground Water Sample Preservation at ISCO Sites – Recommended Guidelines
- A Tracer Test to Characterize Treatment of TCE in a Permeable Reactive Barrier
Ground Water Models
- 2DFATMIC simulates subsurface flow, transport, and fate of contaminants that are undergoing chemical or biological transformation. The model is applicable to transient conditions in both saturated and unsaturated zones. This model can almost eliminate spurious oscillation, numerical dispersion, and peak clipping due to advective transport.
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. This model can almost eliminate spurious oscillation, numerical dispersion, and peak clipping due to advective transport.
3DFEMWATER and 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.
BIOCHLOR is a screening model that simulates remediation by natural attenuation of dissolved solvents at chlorinated solvent release sites. BIOCHLOR includes three different model types: Solute transport without decay, Solute transport with biotransformation modeled as a sequential first-order decay process, and Solute transport with biotransformation modeled as a sequential first-order decay process with two different reaction zones.
- Bioplume II
BIOPLUME II is a simulation that computes concentrations of dissolved hydrocarbon under the influence of oxygen-limited biodegradation in an aquifer. The model solves the solute transport equation for both hydrocarbon and oxygen, assumes an instantaneous reaction between oxygen and hydrocarbon, and combines the two plumes using the principle of superposition.
- Bioplume III
BIOPLUME III is a two-dimensional finite difference model for simulating the natural attenuation of organic contaminants in groundwater due to the processes of advection, dispersion, sorption, and biodegradation. Biotransformation processes are potentially important in the restoration of aquifers contaminated with organic pollutants.
BIOSCREEN is a screening model that simulates remediation through natural attenuation of dissolved hydrocarbons at petroleum fuel release sites. The model is designed to simulate biodegradation by both aerobic and anaerobic reactions.
- Exposure Model for Soil-Organic Fate and Transport (EMSOFT):
- To determine concentrations of contaminants remaining in the soil over a given time (when the initial soil concentration is known);
- To quantify the mass flux (rate of transfer) of contaminants into the atmosphere over time; and
- To subsequently calculate contaminant air concentrations by inputting mass flux values into atmospheric dispersion models.
FOOTPRINT is a screening model used to estimate the length and surface area of benzene, toluene, ethylbenzene, and xylene (BTEX) plumes in groundwater, produced from a gasoline spill that contains ethanol.
- Modular 3-D Multi-Species Transport Model for Simulation of Advection, Dispersion, and Chemical Reactions of Contaminants in Groundwater Systems (MT3D)
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.
- Multimedia Exposure Assessment Model (MULTIMED)
MULTIMED is a one-dimensional, steady-state model used to predict the concentration of contaminants migrating from a waste disposal facility via the subsurface, surface water, and air pathways to receptor sites.
- Nonaqueous-Phase Liquid (NAPL) Simulator
NAPL Simulator conducts a simulation of the contamination of soils and aquifers that results from the release of organic liquids commonly referred to as nonaqueous-phase liquids (NAPLS). The simulator is applicable to three interrelated zones: a vadose zone that is in contact with the atmosphere, a capillary zone, and a water-table aquifer zone.
PRZM3 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. PRZM3 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.
- Remediation Evaluation Model for Chlorinated Solvents (REMChlor)
REMChlor is an analytical solution for simulating the transient effects of groundwater source and plume remediation. In the analytical method, the contaminant source model is based on a power-function relationship between source mass and source discharge, and it can consider partial source remediation at any time after the initial release.
- Remediation Evaluation Model for Fuel hydrocarbons (REMFuel)
REMFuel simulates the transient effects of groundwater source and plume remediation for fuel hydrocarbons. In the analytical method, the contaminant source model is based on a power function relationship between source mass and source discharge for multiple fuel constituents, and it can consider partial source remediation at any time after the initial release.
VLEACH is a one-dimensional, finite difference model for making preliminary assessments of the effects on groundwater 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.
The U.S. EPA's Wellhead Analytic Element Model, WhAEM2000 for Windows (98/NT/2K/XP), is a groundwater geohydrology computer program. WhAEM2000 is a public domain, ground-water flow model designed to facilitate capture zone delineation and protection area mapping in support of the State's Wellhead Protection Programs (WHPP) and Source Water Assessment Planning (SWAP) for public water supplies in the United States. WhAEM2000 provides an interactive computer environment for design of protection areas based on radius methods, well in uniform flow solutions, and geohydrologic modeling methods