Graphical Exposure Modeling System (GEMS)

These include data on the population (including demographic characteristics as well as location of cities), atmosphere, water, and soil characteristics (e.g., climatic, soil property, and stream flow data), ecosystem characteristics, and water supply information. GEMS also includes data sets that identify and characterize potential chemical release sites as well as monitoring stations. These data sets include information on publicly owned wastewater treatment works (POTWs), and industrial facilities, identified through the Permit Compliance System (PCS), the National Emissions Data System (NEDS), and the National Pollutant Discharge Elimination System (NPDES).

In general, the user provides information on the pollutant discharged such as the amount, concentration, or source. However, data are also directly accessible from the Toxic Release Inventory (TRI). Data sets are also available that provide information on chemicals and their properties.

See: "epa.gov/"