U.S. Census Tract Derived Population DataCensus Tracts are small, relatively permanent statistical subdivisions of a county or equivalent entity that are updated by local participants prior to each decennial census as part of the Census Bureau's Participant Statistical Areas Program. The Census Bureau delineates census tracts in situations where no local participant existed or where state, local, or tribal governments declined to participate. The primary purpose of census tracts is to provide a stable set of geographic units for the presentation of statistical data. Census tracts generally have a population size between 1,200 and 8,000 people, with an optimum size of 4,000 people. A census tract usually covers a contiguous area; however, the spatial size of census tracts varies widely depending on the density of settlement. Census tract boundaries are delineated with the intention of being maintained over a long time so that statistical comparisons can be made from census to census. Census tracts occasionally are split due to population growth or merged as a result of substantial population decline. Census tract boundaries generally follow visible and identifiable features. They may follow nonvisible legal boundaries, such as minor civil division (MCD) or incorporated place boundaries in some states and situations, to allow for census-tract-to-governmental-unit relationships where the governmental boundaries tend to remain unchanged between censuses. State and county boundaries always are census tract boundaries in the standard census geographic hierarchy. Tribal census tracts are a unique geographic entity defined within federally recognized American Indian reservations and off-reservation trust lands and can cross state and county boundaries. Tribal census tracts may be completely different from the census tracts and block groups defined by state and county (see 'Tribal Census Tract').U.S. Census BureauSAIC Contractors to the EPA OIAA created the derived data tables.American Community Survey Summary File Technical Documentation, available at https://www.census.gov/acs/www/data_documentation/summary_file/EPA GIS Agency Central SupportU.S. Environmental Protection Agency, Research Triangle ParkOEI RTP NCC GIS919-767-7493USEPA Mailroom N127-02Research Triangle ParkNC27711geoservices@epa.gov20170823EPA GIS Agency Central SupportU.S. Environmental Protection Agency, Research Triangle ParkOEI RTP NCC GIS919-767-7493USEPA Mailroom N127-02Research Triangle ParkNC27711geoservices@epa.govhttps://edg.epa.gov/metadatahttps://geodata.epa.gov/arcgis/rest/services/OEI/ACS_Demographics_by_Tract_2008_2012/MapServerArcGIS Map Service1.0Demographics for US Census Tracts - 2012 (American Community Survey 2008-2012 Derived Summary Tables)2015-11-20U.S. EPA Office of Environmental Information (OEI) - Office of Information Analysis and Access (OIAA)Washington, DCUS Environmental Protection Agency (US EPA)<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This map service displays data derived from the 2008-2012 American Community Survey (ACS). Values derived from the ACS and used for this map service include: Total Population, Population Density (per square mile), Percent Minority, Percent Below Poverty Level, Percent Age (less than 5, less than 18, and greater than 64), Percent Housing Units Built Before 1950, Percent (population) 25 years and over (with less than a High School Degree and with a High School Degree), Percent Linguistically Isolated Households, Population of American Indians and Alaskan Natives, Population of American Indians and Alaskan Natives Below Poverty Level, and Percent Low Income Population (Less Than 2X Poverty Level). The map service was created for inclusion in US EPA mapping applications.</SPAN></P></DIV></DIV></DIV>Shared Enterprise Geodata Services (SEGS)U.S. Environmental Protection Agency, Research Triangle ParkOEI RTP NCC GIS919-767-7493USEPA Mailroom N127-02Research Triangle ParkNC27711geoservices@epa.govPublisherAlabamaAlaskaAmerican SamoaArizonaArkansasCaliforniaCanadaColoradoConnecticutDelawareFloridaGeorgiaHawaiiIdahoIllinoisIndianaIowaKansasKentuckyLouisianaMaineMarylandMassachusettsMexicoMichiganMinnesotaMississippiMissouriMontanaNebraskaNevadaNew HampshireNew JerseyNew MexicoNew YorkNorth CarolinaNorth DakotaOhioOklahomaOregonPennsylvaniaRhode IslandSouth CarolinaSouth DakotaTennesseeTexasUnited StatesUtahVermontVirginiaWashingtonWashington DCWest VirginiaWisconsinWyomingUser2016-11-28T00:00:00HumanEPA GIS Keyword Thesaurus2016-11-28T00:00:00HumanISO 19115 Topic Category2016-08-31T00:00:00societySEGShttps://project-open-data.github.io/schema/#accessLevelStandard Technical Controls<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>None. Please check sources, scale, accuracy, currency and other available information. Please confirm that you are using the most recent copy of both data and metadata. Acknowledgement of the EPA would be appreciated.</SPAN></P></DIV></DIV></DIV>-138.21454852-12.681516456.6522330361.71101572018-08-23T00:00:00Publication date 12/20/2011Federal Program Inventory2016-08-31T00:00:00020:072EPA GIS Agency Central SupportU.S. Environmental Protection Agency, Research Triangle ParkOEI RTP NCC GIS919-767-7493USEPA Mailroom N127-02Research Triangle ParkNC27711geoservices@epa.govEPA GIS Agency Central SupportEPA GIS Agency Central SupportU.S. Environmental Protection Agency, Research Triangle ParkOEI RTP NCC GIS919-767-7493USEPA Mailroom N127-02Research Triangle ParkNC27711geoservices@epa.govEPA GIS Agency Central SupportThis SEGS web service contains polygon layers from the 2008-2012 US Census American Survey database to provide value-added Tracts summary-level tables for US EPA use.Unrestricted Licensehttps://edg.epa.gov/EPA_Data_License.htmlEPA Public Domain License20201103SAIC Contractors to the EPA OIAA created the summary data tables.2011-12-01Created metadata for map service.2012-07-142FDDCEDD-264A-4685-BEA0-70E53B8A01DF15000000050001.0NAPEPSG