Tyler D. Johnson, United States Geological Survey Kenneth Belitz, United States Geological Survey 20210928 Raster Digital Data Set Reston, VA U.S. Geological Survey Johnson, T.D., Belitz, K., Kauffman, L.J., Wilson, J.T., and Watson, E., 2021. Estimated equivalent population using groundwater for public supply domestic use in the conterminous U.S. 2010, hydrogeologic mapping units, and wells used. U.S. Geological Survey data release, doi:10.5066/P97Y8D6Q https://doi.org/10.5066/P97Y8D6Q Tyler D. Johnson Kenneth Belitz Leon J. Kauffman Elise Watson John T. Wilson 202202 publication Science of The Total Environment vol. 806 n/a Elsevier BV ppg. 150618 https://doi.org/10.1016/j.scitotenv.2021.150618 The population using public supply drinking water was mapped in two ways: the census enhanced method (CEM) evenly distributes the population across the census block-group, and the urban land-use enhanced method (ULUEM) distributes the population only to certain urban land use designations in order to more precisely locate public supply users. This dataset consists of the estimated population using public supply surface water distributed across block-groups. The purpose of this work is to provide a high-resolution map of the population dependent on public supply surface water for the conterminous U.S. 20100701 ground condition Complete Not planned -127.8904 -65.3218 51.5817 22.8719 ISO 19115 Topic Category geoscientificInformation USGS Thesaurus public supply surface water drinking water USGS Metadata Identifier USGS:6055267dd34e1894882d0aa2 Common geographic areas United States None. Please see 'Distribution Info' for details. None. Tyler Johnson U.S. Geological Survey, SOUTHWEST REGION Research Geographer mailing address

4165 Spruance Road

San Diego CA 92101-0821 US 619-225-6137 619-225-6101 tyjohns@usgs.gov ESRI ArcPro v2.5/ ArcMap 10.7. No formal attribute accuracy tests were conducted. No formal logical accuracy tests were conducted. Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. A formal accuracy assessment of the horizontal positional information in the data set has not been conducted. This map product is most appropriately used for block-group sized or larger analysis. A formal accuracy assessment of the vertical positional information in the data set has either not been conducted, or is not applicable. Steven Manson Jonathan Schroeder David Van Riper Steven Ruggles 2017 publication n/a Minneapolis, MN: University of Minnesota https://doi.org/10.18128/d050.v12.0 Digital and/or Hardcopy Resources 20100701 ground condition Source Input 1 Census Total population data by Census block, 2010 Tyler Johnson Kenneth Belitz 2019 dataset https://www.sciencebase.gov U.S. Geological Survey https://doi.org/10.5066/p9fslu3b Digital and/or Hardcopy Resources 20150701 ground condition Source Input 2 BGM SSg The data source provided the estimated number of people using self-supplied groundwater (SSg) (also called "domestic supply"). Data is provided at 1km pixel scale raster tiff image. Cheryl A. Dieter Molly A. Maupin Rodney R. Caldwell Melissa A. Harris Tamara I. Ivahnenko John K. Lovelace Nancy L. Barber Kristin S. Linsey 2018 publication n/a US Geological Survey https://doi.org/10.3133/cir1441 Digital and/or Hardcopy 20150101 20151231 publication date Source Input 3 NWU The national water use report (NWU) was used to calculate the fraction of groundwater vs surface water used in each county. U.S. Department of Commerce, U.S. Census Bureau, Geography Division 20150701 vector digital data https://www2.census.gov/geo/tiger/TIGER2015/COUNTY/ Digital and/or Hardcopy 20150701 ground condition Source Input 4 U.S. Counties 2015 This dataset provided the polygon boundaries for the counties. Three primary datasets were used to develop a high resolution map of the populations using pubic supply groundwater: (1) total US Census population data for 2010 from the National Historic Geographic Information System (See Source Input 1 Census), (2) population using self-suppled groundwater from the 2010 “Block-Group Method” map (See Source Input 2 BGM), and (3) the USGS National Water Use (NWU) county data from 2015 (See Source Input 3 NWU). The first step required a high-resolution pixel map of the total population in the conterminous U.S. to be generated so that it could be used in further analyses. Tabular block-level population data (the highest resolution geometry available from the Census) were downloaded from the NHGIS and joined to their respective census-block polygons. These polygons were converted to a grid with 100-meter (m) pixel sizes (10,000 m2). Due to the large numbers of polygons, the process proceeded one State at a time. The data were subsequently aggregated to a larger 1km2 grid-cell size in order to match the grid size and spacing of the previously published domestic well population dataset by Johnson et al. (2019). This was done so that the two grids can be subtracted from one another to create a pixel map of the total population using public supply (PSt) in Step 2. Source Input 1 Census 20191101 The estimated population using self-supplied groundwater (Source Input 2 BGM SSg) was subtracted from total population computed in Step 1. The resulting difference is the estimated total population using public supply (PSt). Any negative values were set to 0. Source Input 2 BGM SSg 20191115 The 2015 NWU report (Source Input 3 NWU) was used to create a public supply groundwater fraction (PSgF) used to calculate the fraction of groundwater vs surface water used in each county. In about 60% of the counties the NWU reported public supply groundwater population (NWU_PSg) was divided by the reported total public supply population (NWU_PSt). In the approximately 40% of the counties where NSU_PSg was not reported, the fraction was computed using volumes in millions of gallons per day (Mgal/d) instead of population. The PSgF was joined to each County polygon (Source Input 4) and then converted into 1km cell size grid so that the pixels match up with all other generated grids. Source Input 3 NWU Source Input 4 U.S. Counties 2015 20191201 The public supply groundwater fraction (PSgF) calculated in Step 3 was multiplied by the estimated total population using public supply (PSt) calculated in Step 2 on a pixel by pixel basis. The result is estimated equivalent population served by public supply groundwater (PSg). 20201215 The total population on public supply consists of the population using groundwater and the population using surface water. Subtracting the PSg population grid created in Step 4 from the PSt population grid created in Step 2 results in the population using public supply surface water (PSs). 20201215 Raster Grid Cell 2904 4616 1 Albers Conical Equal Area 29.5 45.5 -96.0 23.0 0.0 0.0 row and column 1000.0 1000.0 meters North_American_Datum_1983 GRS 1980 6378137.0 298.2572221010042 US_PSs_2010_CEM.tif Raster geospatial data file. Producer Defined Value Unique numeric values contained in each raster cell. Values represent estimated equivalent population using public supply surface water expressed in people per square kilometer (which is the same size as the pixel). Producer Defined -9999 No data available. Producer defined 0.0 50509.05859375 The entity and attribute information provided here describes the tabular data associated with the data set. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the data set. The entity and attribute information was generated by the individual and/or agency identified as the originator of the data set. Please review the rest of the metadata record for additional details and information. U.S. Geological Survey GS ScienceBase mailing address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of these data, software, or related materials. The use of firm, trade, or brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. The names mentioned in this document may be trademarks or registered trademarks of their respective trademark owners. Raster Digital Data Set ArcGIS 10.5 ESRI File Geodatabase Raster This WinZip file contains the file geodatabase https://doi.org/10.5066/P97Y8D6Q None. No fees are applicable for obtaining the data set. 20240731 Tyler Johnson U.S. Geological Survey, SOUTHWEST REGION Research Geographer mailing address

4165 Spruance Road

San Diego CA 92101-0821 US 619-225-6426 619-225-6436 tyjohns@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 local time