Exposure Assessment Models

Listed below are some of the recent additions and updates available on the Exposure Assessment Models Web site maintained by the EPA Center for Exposure Assessment Modeling (CEAM). To receive e-mail notification of additions and updates, you may subscribe to the CEAM discussion listserver.

March 2008

• CEAM has posted an updated Microsoft Excel 2003 based model, SERAFM (Spreadsheet-based Ecological Risk Assessment for the Fate of Mercury). SERAFM is a process-based, steady-state modeling system incorporating a series of process modules that predict speciated mercury concentrations (Hg0, HgII, MeHg, HgT) in water (filtered and unfiltered) and sediments, and total mercury concentrations in fish tissue.
• Please refer to the release notes for a detailed list of releases and changes.

March 2008

• The Bioaccumulation and Aquatic System Simulator (BASS) has been posted on CEAM. BASS is a model that simulates the population and bioaccumulation dynamics of age-structured fish communities.
• BASS has be used to:
  • investigate the bioaccumulation of chemical pollutants within a community or ecosystem
  • explore population and community dynamics of fish assemblages that are exposed to a variety of nonchemical stressors such as altered thermal regimes associated with hydrological alterations or industrial activities, commercial or sports fisheries, and introductions of non native or exotic fish species.

September 2007

• An updated version of the U.S. EPA's Wellhead Analytic Element Model, WhAEM2000, has been posted on the CEAM web site. WhAEM2000 for Windows (98/NT/2K/XP), is a groundwater flow model designed to facilitate capture zone delineation and protection area mapping.
• A detailed list of changes is available in the release notes.

September 2007

• The Environmental Fluid Dynamics Code (EFDC) has been posted on CEAM. EFDC is a multifunctional surface water modeling system which includes hydrodynamic, sediment-contaminant, and eutrophication components.
• EFDC has be used to:
  • study high fresh water inflow events in the northern portion of the Indian River Lagoon, Florida
  • model flow through high vegetation density-controlled wetland systems in the Florida Everglades.
  • discharge dilution studies in the Potomac, James and York Rivers.
  • salinity intrusion studies include the York River, Indian River Lagoon and Lake Worth.
  • sediment transport studies include the Blackstone River, James River, Lake Okeechobee, Mobile Bay, Morro Bay, San Francisco Bay, Elliott Bay - Lower Duwamish Waterway, and Stephens Passage.
  • power plant cooling studies include Conowingo Reservoir, the James River and Nan Wan Bay.
  • contaminant transport and fate studies include the Blackstone and Housatonic Rivers, James River, San Francisco Bay, and Elliott Bay - Lower Duwamish Waterway.
  • water quality eutrophication studies include Norwalk Harbor, Peconic Bay, the Christina River Basin, the Neuse River, Mobile Bay, the Yazoo River Basin, Arroyo Colorado, Armand Bayou, Tenkiller Reservoir, and South Puget Sound.

August 2007

• CEAM has posted an updated version of the Web-based Interspecies Correlation Estimation (Web-ICE). Web-ICE estimates the acute toxicity of a chemical to a taxon (i.e., the predicted species, genera, or family) without test data from the known toxicity of the chemical to a species with test data (the surrogate).
• WebICE now provides expanded functionality for aquatic taxa models and sensitivity distributions.
• A JavaScript-enabled web browser is required to operated Web-ICE.

August 2007

• The EXAMS - PRZM Exposure Simulation Shell (EXPRESS) model has been updated and posted on CEAM. EXPRESS is designed to facilitate a rapid and consistent assessment of aquatic pesticide exposure on a variety of crops. EXPRESS is a joint project of the USEPA Office of Pesticide Programs' Environmental Fate and Effects Division (OPP/EFED) and the USEPA Office of Research and Development (ORD). A detailed list of changes is available in the release notes.

May 2007

• Web-based Interspecies Correlation Estimation (Web-ICE) has been posted on CEAM. Web-ICE estimates the acute toxicity of a chemical to a taxon (i.e., the predicted species, genera, or family) without test data from the known toxicity of the chemical to a species with test data (the surrogate). ICE models are least square regressions between the surrogate species and the predicted taxa to estimate the toxicity of that chemical to the predicted species, genus or family. Web-ICE replaces the desktop application, ICE. A JavaScript-enabled web browser is required to operated Web-ICE.
• Web-ICE can be used to:
  • Predict toxicity to wildlife taxa.
  • Generate Species Sensitivity Distributions.

April 2007

• CEAM has posted a new ecosystem assessment tool, Watershed Health Assessment Tools Investigating Fisheries (WHATIF). WHATIF is software that integrates a number of calculators, tools, and models for assessing the health of watersheds and streams with an emphasis on fish communities in the Mid-Atlantic Highland region. The tool set consists of hydrologic and stream geometry calculators, a fish assemblage predictor, a fish habitat suitability calculator, macro-invertebrate biodiversity calculators, and a process-based model to predict biomass dynamics of stream biota (the BASS model).
• These models can be used to:
  • Watershed health assessment.
  • Prediction of stream hydraulic geometry based on mean annual flow conditions.
  • Prediction of stream hydraulic geometry based on Bankfull flow conditions.
  • Prediction of fish habitat suitability.
  • Prediction of fish assemblage.
  • Prediction of macro-invertebrate biodiversity (EPT and MBII).
  • Simulation of bio-accumulation.
  • Investigate sensitivity of processes and model parameters.
  • Screening analysis, such as prioritization of areas for restoration and comparison of alternative watershed and habitat management scenarios.

February 2007

• CEAM has re-posted the 3DFEMWATER/3DLEWASTE models (source code only). 3DFEMWATER/3DLEWASTE, 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. A detailed list of changes is available in the release notes

October 2006

• CEAM has posted a new Microsoft Excel 2003 based model, SERAFM (Spreadsheet-based Ecological Risk Assessment for the Fate of Mercury). SERAFM is a process-based, steady-state modeling system incorporating a series of process modules that predict speciated mercury concentrations (Hg0, HgII, MeHg, HgT) in water (filtered and unfiltered) and sediments, and total mercury concentrations in fish tissue.
• SERAFM was specifically developed to serve as a screening-level tool to investigate mercury cycling and exposure concentrations in water bodies and associated impacted wildlife exposure risk, as well as a research tool to investigate mercury processes within the watershed and water body.

October 2006

• CEAM has updated the EXPRESS model (EXAMS - PRZM Exposure Simulation Shell). EXPRESS is designed to facilitate a rapid and consistent assessment of aquatic pesticide exposure on a variety of crops. EXPRESS is a joint project of the USEPA Office of Pesticide Programs' Environmental Fate and Effects Division (OPP/EFED) and the USEPA Office of Research and Development (ORD). A detailed list of changes is available in the release notes.

May 2006

• CEAM has updated the PRZM3. 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. A detailed list of changes is available in the release notes.

May 30, 2006

• CEAM has updated the MINTEQA2 model for use on Windows 2000 and XP computer systems. The MINTEQA2 model and its associated PRODEFA2 software were recompiled and released as version 4.03. Model functionality remains unchanged, however, the system is now compatible with a wider range of Windows operating systems. A detailed list of changes is available in the release notes.
• A new component database containing Monomethylmercury (MMHg) and Tributyltin (TBT) is also distributed with MINTEQA2 version 4.03. The addition of this new database and accompanying documentation will permit researchers to simulate the aqueous chemical speciation of MMHg and TBT.

April 17, 2006

• Two models developed by the EPA National Health and Environmental Effects Research Laboratory (NHEERL) are now available through CEAM.
• The Interspecies Correlation Estimations (ICE) for Acute Toxicity to Aquatic Organisms and Wildlife program was developed to allow prediction of acute toxicity to taxa with limited toxicity databases such as endangered species.
• The Acute-to-Chronic Estimation (ACE) with Time-Concentration-Effect Models program was developed to allow prediction of chronic toxicity from acute toxicity datasets.

January 10, 2006

• Hurricane Katrina Modeling Demonstration - EPA and Battelle have a CRADA agreement to attempt to link near-field models, such as the Visual Plumes UM3 model, with large-scale hydrodynamic models, such as Battelle's implementation of the Finite Volume Coastal Ocean Model (FVCOM). This download is a preliminary demonstration of FVCOM applied to flood waters generated by Hurricane Katrina and discharged to Lake Pontchartrain.

Additions and updates on the Exposure Assessment Models Web site prior to 2006 are available.