Envirofacts Points are maintained by the Envirofacts Warehouse. These points are latitude and longitude coordinates for the following types of regulated facilities: Discharges to Water, Superfund Sites, Hazardous Waste Handlers, Toxic Releases, Air Emissions and Biennial Reporting System (BRS) In many cases, facilities report more than one environmental activity to EPA. These are designated as "multi-activities" or "multiple-program-system" facilities.
Schools, Churches, Hospitals, and Populated Places are extracted from Geographic Names Information System (GNIS) 
which is part of EPA's National Geospatial Data Clearinghouse.
The County, State, Stream, Streets, and Waterbodies layers are extracted from GDT's Wessex , which is a division of Geographic Data Technology .
EnviroMapper's ZIP Code Regions layer is generated using Geographic Data Technologies (GDT) Dynamap/ZIP .
The Department of Transportation's (DOT) Office of Geographic Information Services provides the Major Roads layer for EnviroMapper.
provides the Railroads layer for EnviroMapper.
The Watersheds layer is composed of the U.S. Geological Survey Hydrologic Catalog Units.
The Federal Lands layer is downloaded from the United States Geological Survey Map Layers Warehouse . This map layer portrays the federally administered lands of the United States that have any area equal to or greater than 640 acres.
The Interstates layer is extracted from DOT Major Roads.