The below provides basic descriptions for the data included in the mapping layers available through NEPAssist. Be sure to use the appropriate metadata (data layer title, source and date) when citing the source of your supporting data.
The below includes information EPA collects through various databases about facilities or sites subject to environmental regulation.
Description: Hazardous waste information contained in the Resource Conservation and Recovery Act Information (RCRAInfo) includes an inventory on all generators, transporters, treaters, storers, and disposers of hazardous waste that are required to provide information about their activities.
Source: EPA's Envirofacts
Description: The air pollution data (ICIS-AIR) contains compliance and permit data for stationary sources of air pollution (such as electric power plants, steel mills, factories, and universities) regulated by EPA, state and local air pollution agencies. The information in ICIS-AIR is used by the states to prepare State Implementation Plans (SIPs) and to track the compliance status of point sources with various regulatory programs under Clean Air Act.
Source: EPA's Envirofacts
Description: As authorized by the Clean Water Act, the National Pollutant Discharge Elimination System (NPDES) permit program controls water pollution by regulating sources, such as municipal and industrial wastewater treatment facilities, that discharge pollutants into waters of the United States. EPA tracks water discharge permits through the Permit Compliance System (PCS) and Integrated Compliance Information System (ICIS) databases, which includes information on when a permit was issued and when it expires, how much the company is permitted to discharge, and the actual monitoring data showing what the company has discharged.
Source: EPA's Envirofacts
Description: The Toxics Release Inventory (TRI) contains information on toxic chemical releases and waste management activities reported annually by certain industries as well as federal facilities. The database also contains links to compliance and enforcement information.
Source: EPA's Envirofacts
Description: The Superfund Enterprise Management System (SEMS) provides information regarding sites under the Comprehensive Environmental Response, Compensation, and Liability Act -- otherwise known as CERCLA or Superfund. CERCLA provides a Federal "Superfund" to locate, investigate, and clean up uncontrolled or abandoned hazardous-waste sites as well as accidents, spills, and other emergency releases of pollutants and contaminants into the environment. The National Priorities List (NPL) is the list of national priorities among the known releases or threatened releases of hazardous substances, pollutants, or contaminants throughout the United States and its territories.
Source: EPA's Envirofacts
Description: The Assessment, Cleanup and Redevelopment Exchange System (ACRES) captures grantee reported data on environmental activities and accomplishments (assessment, cleanup and redevelopment), funding, job training, and details on cooperative partners and leveraging efforts for the Brownfields Program. The information in ACRES is provided at the property and grant level.
Source: EPA's Envirofacts
Description: The USGS Water Monitors layer is retrieved in real-time from the United States Geological Survey (USGS) National Water Information System (NWIS). The NWIS service provides current conditions from selected surface water, ground water, and water quality sites.
Source: U.S. Geological Survey National Water Information System (NWIS)
Date: See source metadata by following the Source link above for the latest date information.
Description: Water quality monitoring information comes from EPA's Storage and Retrieval (STORET) System, a repository of physical, chemical and biological monitoring data from state and federal agencies, watershed organizations, volunteer groups and many others. Surface water, Ground water, and Others are general categories for more specific STORET Station Types.
Source: EPA's Storage and Retrieval (STORET) System
Date: See source metadata by following the Source link above for the latest date information.
National Register of Historic Places
Description: The National Register of Historic Places is the official list of the nation's historic places worthy of preservation. Authorized by the National Historic Preservation Act of 1966, the National Register is the official Federal list of districts, sites, buildings, structures, and objects significant in American history, architecture, archeology, engineering, and culture. The National Register is managed and maintained by the National Park Service (NPS) and directed by the Keeper of the National Register. The National Register layer is downloaded from the NPS National Register of Historic Places geodatabase file.
Source: U.S. Department of the Interior National Park Service
Spatial Metadata: National Register of Historic Places
Date: See the source metadata by following the Source link above for the latest date information.
Description: Point locations for educational facilities in the USA, including buildings or groups of buildings used as an institution for study, teaching, and learning (e.g., academy, college, high school, university).
Source: U.S. Geological Survey Geographic Names Information System (GNIS)
Spatial Metadata: Schools
Date: See source metadata by following the Source link above for the latest date information.
Description: Point locations for buildings used for religious worship (e.g., chapel, mosque, synagogue, tabernacle, or temple).
Source: U.S. Geological Survey Geographic Names Information System (GNIS)
Spatial Metadata: Worship Places
Date: See source metadata by following the Source link above for the latest date information.
Description: Point locations for buildings where the sick or injured may receive medical or surgical attention (e.g., infirmary, clinic).
Source: U.S. Geological Survey Geographic Names Information System (GNIS)
Spatial Metadata: Hospitals
Date: See source metadata by following the Source link above for the latest date information.
Description: The Airport layer includes points for landing facilities in the United States that were provided and maintained by the Federal Aviation Administration.
Source: National Transportation Atlas Database
Spatial Metadata: Airports Point
Date: See Spatial Metadata above for the latest date information.
Description: The Airport Polygons layer includes airport boundaries and airport runways within the United States.
Source: Data and Maps for ArcGIS
Spatial Metadata: Airports Polygon
Date: See Spatial Metadata above for the latest date information.
Description: The Railroads layer includes linear features representing the United State's railway system. The Railroads layer is provided and maintained by the Federal Railroad Administration.
Source: National Transportation Atlas Database
Spatial Metadata: Railroads
Date: See Spatial Metadata above for the latest date information.
Description: The Impaired Water Points layer includes points that are too polluted or otherwise degraded to meet the water quality standards set by states, territories, or authorized tribes. These water points are on the CWA 303(d) list and are required to develop a total maximum daily load (TMDL). This set of water points are provided by the Assessment, Total Maximum Daily Load Tracking and Implmentation System (ATTAINS).
Source: EPA Office of Water ATTAINS Geospatial Data
Spatial Metadata: ATTAINS Assessement Areas
Date: 2020
Description: The Impaired Streams layer includes streams that are too polluted or otherwise degraded to meet the water quality standards set by states, territories, or authorized tribes. These streams are on the CWA 303(d) list and are required to develop a total maximum daily load (TMDL). These stream segments are provided by the Assessment, Total Maximum Daily Load Tracking and Implmentation System (ATTAINS).
Source: EPA Office of Water ATTAINS Geospatial Data
Spatial Metadata: ATTAINS Assessment Lines
Date: 2020
Description: The Impaired Water Bodies layer includes bodies of water that are too polluted or otherwise degraded to meet the water quality standards set by states, territories, or authorized tribes. These water bodies are on the CWA 303(d) list and are required to develop a total maximum daily load (TMDL). This set of water areas are provided by the Assessment, Total Maximum Daily Load Tracking and Implmentation System (ATTAINS).
Source: EPA Office of Water ATTAINS Geospatial Data
Spatial Metadata: ATTAINS Assessement Areas
Date: 2020
Description: The Impaired Catchment layer includes catchment assessment units that are too polluted or otherwise degraded to meet the water quality standards set by states, territories, or authorized tribes. These water bodies are on the CWA 303(d) list and are required to develop a total maximum daily load (TMDL). This set of water areas are provided by the Assessment, Total Maximum Daily Load Tracking and Implmentation System (ATTAINS).
Source: EPA Office of Water ATTAINS Geospatial Data
Spatial Metadata: ATTAINS Assessement Areas
Date: 2020
Description: The Streams layer includes linear surface water features throughout the United States. The streams layer is based on the National Hydrography Dataset (NHD).
Source: EPA Office of Water
Spatial Metadata: Streams
Date: 2005
Description: The Water Bodies layer includes area surface features such as ponds, lakes and wide rivers. The water bodies layer is from U.S. Census Bureau TIGER/Line data.
Source: U.S. Census Bureau Areal Hydrography
Spatial Metadata: Water Bodies
Date: 2019
Description: The Sole Source Aquifer layer includes information on the sole source aquifers (SSA) designated by EPA under section 1424(e) of the Safe Drinking Water Act of 1974. SSA's supply at least 50 percent of the drinking water consumed in the area overlying the aquifer. These areas may have no alternative drWatinking water source(s) that could physically, legally and economically supply all those who depend on the aquifer for drinking water.
Source: SSA Locations
Spatial Metadata: Sole Source Aquifers
Date: 2018
Description: The Watershed (HUC12) layer includes a complete digital hydrologic unit boundary layer to the Subwatershed (12-digit) 6th level for the entire United States.
Source: USGS National Map Hydrography Products
Spatial Metadata: Watershed (HUC12)
Date: 2020
Description: The Watershed (HUC8) layer is a complete digital hydrologic unit boundary layer to Catalog Unit (8-digit) for the entire United States, Puerto Rico and the U.S. Virgin Islands.
Source: National Atlas of the United States
Spatial Metadata: Watershed (HUC8)
Date: 2005
Description: The Wild and Scenic Rivers layer includes segments of the National Wild and Scenic River System for the United States. The National Wild and Scenic Rivers Act protects wild rivers and scenic rivers from development that would substantially change their wild or scenic nature. The act was signed into law on October 2, 1968. Selected rivers in the United States are preserved for possessing outstandingly remarkable scenic, recreational, geologic, fish and wildlife, historic, cultural, or other similar values. Rivers, or sections of rivers, so designated are preserved in their free-flowing condition and are not dammed or otherwise impeded. National Wild and Scenic Rivers are each managed by one or more agencies of the federal or state government. For the full listing of designated Wild and Scenic Rivers, complete with mileage, classifications and managing agencies, view the Wild and Scenic Rivers Table
Source: National Wild and Scenic Rivers System
Spatial Metadata: Wild and Scenic Rivers
Date: See source metadata by following the Source link above for the latest date information.
Description: Ozone 8-hr (1997 standard)
Source and Spatial Metadata: Ozone 8-hr (1997 standard)
Date: See source metadata by following the Source link above for the latest date information.
Description: Ozone 8-hr (2008 standard)
Source and Spatial Metadata: Ozone 8-hr (2008 standard)
Date: See source metadata by following the Source link above for the latest date information.
Description: Ozone 8-hr (2015 standard)
Source and Spatial Metadata: Ozone 8-hr (2015 standard)
Date: See source metadata by following the Source link above for the latest date information.
Description: Lead (2008 standard)
Source and Spatial Metadata: Lead (2008 standard)
Date: See source metadata by following the Source link above for the latest date information.
Description: SO2 1-hr (2010 standard)
Source and Spatial Metadata: SO2 1-hr (2010 standard)
Date: See source metadata by following the Source link above for the latest date information.
Description: PM2.5 24hr (2006 standard)
Source and Spatial Metadata: PM2.5 24hr (2006 standard)
Date: See source metadata by following the Source link above for the latest date information.
Description: PM2.5 Annual (1997 standard)
Source and Spatial Metadata: PM2.5 Annual (1997 standard)
Date: See source metadata by following the Source link above for the latest date information.
Description: PM2.5 Annual (2012 standard)
Source and Spatial Metadata: PM2.5 Annual (2012 standard)
Date: See source metadata by following the Source link above for the latest date information.
Description: PM10 (1987 standard)
Source and Spatial Metadata: PM10 (1987 standard)
Date: See source metadata by following the Source link above for the latest date information.
Description: CO (1971 Standard)
Source and Spatial Metadata: CO (1971 Standard)
Date: See source metadata by following the Source link above for the latest date information.
Ozone 1-hr (1979 standard-revoked)
Description: Ozone 1-hr (1979 standard-revoked)
Source and Spatial Metadata: Ozone 1-hr (1979 standard-revoked)
Date: See source metadata by following the Source link above for the latest date information.
Description: NO2 (1971 Standard)
Source and Spatial Metadata: NO2 (1971 Standard)
Date: See source metadata by following the Source link above for the latest date information.
Description: The Zip Codes layer provides information and identifies each postal delivery area in the United States.
Source: Data and Maps for ArcGIS
Spatial Metadata: Zip Codes
Date: See Spatial Metadata link above for the latest date information.
Description: The Congressional Districts layer includes information on the 118th Congressional Districts of the United States, and U.S. Territories.
Source: ArcGIS Map Service
Spatial Metadata: Congressional Districts
Date: See Spatial Metadata link above for the latest date information.
Description: The City Boundaries layer includes incorporated cities and Census Designated Places from the U.S. Census Bureau TIGER/Line data.
Source: U.S. Census Bureau
Spatial Metadata: City Boundaries
Date: See Spatial Metadata link above for the latest date information.
Description: Urban Areas are downloaded from the 2023 U.S. Census Bureau TIGER/Line Urban Areas. Census defines an urban area as comprised of a densely settled core of census blocks that meet minimum housing unit density and/or population density requirements. This includes adjacent territory containing non-residential urban land uses. To qualify as an urban area, the territory identified according to criteria must encompass at least 2,000 housing units or have a population of at least 5,000.
Source: U.S. Census TIGER/Line (National Nation-Level Geography Geodatabase)
Spatial Metadata: Urban Areas
Date: See Spatial Metadata link above for the latest date information.
Description: The Federal Lands layer includes information on lands owned or administered by the Federal government. This layer is downloaded from the U.S. Geological Survey (USGS).
Source: USGS National Geospatial Program Small-Scale Data
Spatial Metadata: Federal Lands
Date: See Spatial Metadata link above for the latest date information.
Description: The Townships Boundary layer portrays the Public Land Survey System (PLSS) boundaries of the United States to the township level. This layer is downloaded from the Bureau of Land Management (BLM) PLSS Map Service.
Source: Bureau of Land Management PLSS Townships
Spatial Metadata: Townships Boundary
Date: See Spatial Metadata link above for the latest date information.
Description: The Counties layer portrays the county boundaries of the United States.
Source: U.S. Census Bureau
Spatial Metadata: Counties
Date: See Spatial Metadata link above for the latest date information.
Description: The State layer provides state boundaries of the United States.
Source: U.S. Census Bureau
Spatial Metadata: States
Date: See Spatial Metadata link above for the latest date information.
Description: The EPA Regions layer includes EPA Administrative Region boundaries derived from State boundaries.
Source: EPA Office of Environmental Information (OEI)
Spatial Metadata: EPA Regions
Date: See Spatial Metadata link above for the latest date information.
Demographics information is available to add to the NEPAssist map under the “More Data” button. You may click on the associated button to see metadata for that data layer. Please see the Census Bureau website for more explanations regarding Census Bureau data from the 2010 Census Summary File 1 (SF1) 100% count data and the annual American Community Survey (ACS) estimates using the 2016-2020 ACS 5-Year Summary database. Please note that all variables that show the percent rather than count were derived from count-based Census variables using the standard approach of count divided by total population of the population in question.
Description: The NWI Wetlands layer includes information from the National Wetland Inventory (NWI) which was established by the U.S. Fish and Wildlife Service (FWS) to conduct a nationwide inventory of U.S. wetlands to provide biologists and others with information on the distribution and type of wetlands to aid in conservation efforts.
Source: U.S. Fish and Wildlife Service NWI Wetlands
Spatial Metadata: NWI Wetlands
Date: See Spatial Metadata above for the latest date information.
Description: The Critical Habitat layer includes critical habitat designated by the U.S. Fish and Wildlife Service for all threatened species and endangered species under the Endangered Species Act, with certain specified exceptions. Critical habitat is a habitat area essential to the conservation of a listed species, though the area need not actually be occupied by the species at the time it is designated. It is important to understand that the designated critical habitat that is displayed in the map does not represent all of the critical habitat designated by the U.S. Fish & Wildlife Service. For complete information about all species with designated critical habitat, go to the Critical Habitat Data folder on the U.S. Fish & Wildlife Service Critical Habitat Report.
Source: U.S. Fish and Wildlife Service
Spatial Metadata: Critical Habitat Report
Date: See Spatial Metadata above for the latest date information.
Description:The FEMA Flood layer represents Flood Insurance Rate Map (FIRM) data important for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP) provided by the Federal Emergency Management Agency (FEMA). The National Flood Hazard Layer (NFHL) data present the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications.
Source and Spatial Metadata: FEMA's National Flood Hazard Layer
Date: See source metadata by following the Source link above for the latest date information.
Description: The National Land Cover layer includes information from the National Land Cover Database (NLCD) which includes land cover classification schemes and quantifies land cover change for the conterminous U.S. between the years 2006 to 2019.
Source and Spatial Metadata: U.S. Geological Survey
Date: 2019
Description: The formerly used Defense Site Public Property boundaries. The facility or site (property) that was under the jurisdiction of the Secretary of Defense and owned by, leased to, or otherwise possessed by the United States at the time of actions leading to contamination by hazardous substances. The FUDS program is limited to those real properties that were transferred from DoD control prior to October 17, 1986. Properties must be located within the United States.
Source: Defense Sites
Spatial Metadata: Defense Sites
Date: 2023
Description: FUDS Public Munitions Response sites. The discrete location within a Munitions Response Area that is known to require a munitions response.
Source: Munitions Response Sites
Spatial Metadata: Munitions Response Sites
Date: 2023
Description: Essential Fish Habitat are those areas that have been identified and described by species and lifestage. Fish require healthy surroundings to survive and reproduce. Essential fish haitat includes all types of aquatic habitat - wetlands, coral reefs, sea-grasses, rivers - where fish spawn, breed, feed, or growh to maturity. EFH Mapper Data is a combination of three existing data layers: Essential Fish Habitat (EFH), Habitat Areas of Particular Concern (HAPC) and EFH Areas Protected from Fishing (EFHA).
Source and Spatial Metadata: Essential Fish Habitat
Date: 2021
Description: The purpose of HAPCs is to focus conservation, management, and research efforts on subsets of EFH that are vulnerable to degradation or are especially important ecologically for federally managed fish. The HAPC designation alone does not confer additional protection or restrictions to an area, but helps to focus EFH conservation, management, and research priorities. HAPC designation is a valuable way to acknowledge areas where we have detailed information on ecological function and habitat vulnerability, indicating a greater need for conservation and management.
Source and Spatial Metadata: HAPC
Date: 2021
Description: This nationwide dataset represents designated EFH areas where fishing or the use of fishing gears had been restricted or modified in order to minimize the adverse effects of fishing on EFH as required by Section 303(a)(7) of the Magnuson Stevens Act.
Source and Spatial Metadata: EFHA
Date: 2021
Critical Environmental Concern
Description: BLM Areas of Critical Environmental Concern. This polygon feature class shows the spatial extent and boundaries of Areas of Critical Environmental Concern that have become officially designated by the BLM. These polygon features were previously in a pre-designated status (i.e. being considered as areas to be eventually designated as official ACEC designated polygons).
Source: Crital Environmental Concern
Spatial Metadata: Critical Environmental Concern
Date: 2023
Critical Habitat Areas per U.S. Fish & Wildlife
Description: Critical habitat areas of threatened and endangered species as defined by U.S. Fish & Wildlife Service
Source: Critical Habitat Areas per U.S. Fish & Wildlife
Spatial Metadata: Critical Habitat Areas per U.S. Fish & Wildlife
Date: 2023
Critical Habitat River, Stream or Water features per U.S. Fish & Wildlife
Description: Critical habitat river, stream or water features of threatened and endangered species as defined by U.S. Fish & Wildlife Service
Source: Critical Habitat River, Stream or Water features per U.S. Fish & Wildlife
Spatial Metadata: Critical Habitat River, Stream or Water features per U.S. Fish & Wildlife
Date: 2023