The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board and the U.S. Bureau of Land Management compiled and analyzed data for mapping groundwater total dissolved solids (TDS) and characterizing clay layers and faults in the Poso Creek Oil Field in Kern County, California. Data for the Poso Creek Oil Field area include analyses of historical produced water samples from oil wells, borehole geophysical data, and geological formation depths. The data reported here are used in an accompanying interpretive manuscript that describes groundwater TDS, stratigraphic layers, and geologic structure in the study area. Some of these data were archived scanned pages in raster format on the California Geologic Energy Management Division (CalGEM) website and have been compiled into computer readable numerical data sets. Other data, such as the stratigraphic markers, were generated by this project from interpreting borehole geophysical data. All the data analyzed are part of the California State Water Resources Control Board oil and gas Regional Monitoring Program and the USGS California Oil, Gas, and Groundwater (COGG) program. First posted: December 13, 2018 Revised: September, 2021

The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board collected produced water and gas samples in the Poso Creek, Midway-Sunset, and Buena Vista Oil Fields in Kern County in 2020 and 2021. Sampled sites included oil wells; injectate from tanks, pipelines, and injection wells where produced water from many wells, after removal of oil, is stored or transported before underground injection; and integrated produced water from multiple oil wells collected from pipelines before oil removal. This digital dataset contains the site information, analyzing laboratories and methods, and water and gas chemistry and quality-control results for these samples. Chemistry results include concentrations of dissolved noble and hydrocarbon gases and their isotopic composition; concentrations of inorganic constituents including salinity, major and minor ions, trace elements, and nutrients; dissolved organic carbon and optical properties of dissolved organic carbon; stable isotopes of water, strontium dissolved in water, and carbon in dissolved inorganic carbon; and radium isotopes. Samples were analyzed in the field and by eight laboratories operated or contracted by the USGS.

The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board collected produced water and gas samples in the Poso Creek, Midway-Sunset, and Buena Vista Oil Fields in Kern County in 2020 and 2021. Sampled sites included oil wells; injectate from tanks, pipelines, and injection wells where produced water from many wells, after removal of oil, is stored or transported before underground injection; and integrated produced water from multiple oil wells collected from pipelines before oil removal. This digital dataset contains the site information, analyzing laboratories and methods, and water and gas chemistry and quality-control results for these samples. Chemistry results include concentrations of dissolved noble and hydrocarbon gases and their isotopic composition; concentrations of inorganic constituents including salinity, major and minor ions, trace elements, and nutrients; dissolved organic carbon and optical properties of dissolved organic carbon; stable isotopes of water, strontium dissolved in water, and carbon in dissolved inorganic carbon; and radium isotopes. Samples were analyzed in the field and by eight laboratories operated or contracted by the USGS.

The California State Water Resources Control Board (State Water Board) initiated the Oil and Gas Regional Monitoring Program (RMP) to assess effects of oil and gas development on groundwater designated for any beneficial use. The U.S. Geological Survey (USGS) is the technical lead in conducting the RMP through the California Oil, Gas, and Groundwater (COGG) Program, working in cooperation with the State Water Board, and in partnership with other State and local agencies. The USGS collected and analyzed groundwater, surface water, and associated quality control (QC) samples in the Poso Creek Oil Field study area during February 2020-December 2021. Groundwater samples were collected from eleven irrigation, two domestic, two public supply, four monitoring wells, two institutional wells, and two surface water sites located within a five km buffer zone surrounding the Poso Creek Oil Field in Kern County, California. Samples were collected using established groundwater data-collection protocols and procedures. Samples were analyzed for water-quality indicators, major and minor ions, nutrients, trace elements, volatile organic compounds (VOCs), naturally occurring radioactive material, geochemical and age-dating tracers, dissolved organic carbon (DOC), dissolved standard and hydrocarbon gases (methane through hexane), and dissolved noble gasses, atmospheric gases, and surrogates. Approximately two hundred and eight constituents and water-quality indicators were measured. QC samples analyzed as part of the Poso Creek Oil Field study included replicates, source-solution blanks, field and equipment blanks, and laboratory spikes and surrogates.

The California State Water Resources Control Board (State Water Board) initiated the Oil and Gas Regional Monitoring Program (RMP) to assess effects of oil and gas development on groundwater designated for any beneficial use. The U.S. Geological Survey (USGS) is the technical lead in conducting the RMP through the California Oil, Gas, and Groundwater (COGG) Program, working in cooperation with the State Water Board, and in partnership with other State and local agencies. The USGS collected and analyzed groundwater, surface water, and associated quality control (QC) samples in the Poso Creek Oil Field study area during February 2020-December 2021. Groundwater samples were collected from eleven irrigation, two domestic, two public supply, four monitoring wells, two institutional wells, and two surface water sites located within a five km buffer zone surrounding the Poso Creek Oil Field in Kern County, California. Samples were collected using established groundwater data-collection protocols and procedures. Samples were analyzed for water-quality indicators, major and minor ions, nutrients, trace elements, volatile organic compounds (VOCs), naturally occurring radioactive material, geochemical and age-dating tracers, dissolved organic carbon (DOC), dissolved standard and hydrocarbon gases (methane through hexane), and dissolved noble gasses, atmospheric gases, and surrogates. Approximately two hundred and eight constituents and water-quality indicators were measured. QC samples analyzed as part of the Poso Creek Oil Field study included replicates, source-solution blanks, field and equipment blanks, and laboratory spikes and surrogates.

This data release Child Item contains groundwater elevation data and the associated model/code used to create groundwater elevation surfaces in and around the Poso Creek Oil Field. The data and model provided here are part of an interpretative manuscript by McMahon and others (2023). The data compiled and analyzed here are part of the California State Water Resources Control Board Oil and Gas Regional Monitoring Program and the U.S. Geological Survey California Oil, Gas, and Groundwater (COGG) Program.

This data release Child Item contains groundwater elevation data and the associated model/code used to create groundwater elevation surfaces in and around the Poso Creek Oil Field. The data and model provided here are part of an interpretative manuscript by McMahon and others (2023). The data compiled and analyzed here are part of the California State Water Resources Control Board Oil and Gas Regional Monitoring Program and the U.S. Geological Survey California Oil, Gas, and Groundwater (COGG) Program.

This digital dataset contains historical geochemical and other information for 100 samples of groundwater from 71 wells located within 3 miles of the Poso Creek Oil Field in Kern County, California. An additional 12 wells in the Poso Creek study area, but co-located within 3 miles of the adjacent Rosedale and Rosedale Ranch Oil Fields, were not included in this data release; these data are planned for a future data release associated with those fields. The sampled wells include water-supply wells used primarily for domestic, irrigation, and industrial uses. Numerical water chemistry data were compiled from two data sources: 1) Kern County Public Health Services Department (KCPHSD) PDF (Portable Document Format) files, and 2) the Eastside Water Management Area (EWMA) Groundwater Sustainability Plan (GSP) Chapter. These data sources include varying location and well-construction information. Locations for most of the wells represent either well-specific coordinates provided in the KCPHSD PDFs, approximate locations determined using ArcGIS (GIS, Geographic Information System) software based on descriptive information or location maps in the KCPHSD PDFs, parcel centroid coordinates determined from a GIS parcel shapefile (KERN PARCEL) based on parcel numbers provided by either the KCPHSD or EWMA data source, or approximate locations from Google Earth based on visual identification of well locations. For two wells (Dataset_IDs 1 and 2) coordinates represent the locations provided by the California Department of Water Resources Water Data Library (CDWR WDL) as those particular wells are located in that database in association with water-level measurement data. For three wells (Dataset_IDs 22, 30, and 42) having limited information, locations represent meridian, township, range, section, and quarter-quarter section (MTRSQQ) centroids. Information on well construction was compiled from California Department of Water Resources Well Completion Reports (CDWR-WCR) included with the PDFs located on the KCPHSD website, or located on the CDWR Well Completion Reports Map Application website. Well construction from CDWR-WCRs was available for 53 of the 71 wells. For one well (Dataset_ID 5), a WCR could not be located, however, well construction information was available in the EWMA GSP. Data were manually compiled into two separate files described as follows: 1) a summary data file that includes well identifiers, location, construction, the number of chemistry samples, the period of record, specific sample dates for each site, and an inventory of which constituent groups were sampled on each date; and 2) a data file of geochemistry analyses for selected constituents classified into one of the following groups: water-quality indicators, major and minor ions, nutrients, trace elements, naturally occurring radioactive material (NORM), and volatile organic compounds (VOCs). Ion (charge) balance calculations and percent error of these calculations were included for samples having a complete suite of major ion analyses. Parameter code, analytical method, reporting level, reporting level type, and supplemental notes were included where available or pertinent. A data dictionary was created to describe the geochemistry data file and is provided with this data release.

This digital dataset contains historical geochemical and other information for 100 samples of groundwater from 71 wells located within 3 miles of the Poso Creek Oil Field in Kern County, California. An additional 12 wells in the Poso Creek study area, but co-located within 3 miles of the adjacent Rosedale and Rosedale Ranch Oil Fields, were not included in this data release; these data are planned for a future data release associated with those fields. The sampled wells include water-supply wells used primarily for domestic, irrigation, and industrial uses. Numerical water chemistry data were compiled from two data sources: 1) Kern County Public Health Services Department (KCPHSD) PDF (Portable Document Format) files, and 2) the Eastside Water Management Area (EWMA) Groundwater Sustainability Plan (GSP) Chapter. These data sources include varying location and well-construction information. Locations for most of the wells represent either well-specific coordinates provided in the KCPHSD PDFs, approximate locations determined using ArcGIS (GIS, Geographic Information System) software based on descriptive information or location maps in the KCPHSD PDFs, parcel centroid coordinates determined from a GIS parcel shapefile (KERN PARCEL) based on parcel numbers provided by either the KCPHSD or EWMA data source, or approximate locations from Google Earth based on visual identification of well locations. For two wells (Dataset_IDs 1 and 2) coordinates represent the locations provided by the California Department of Water Resources Water Data Library (CDWR WDL) as those particular wells are located in that database in association with water-level measurement data. For three wells (Dataset_IDs 22, 30, and 42) having limited information, locations represent meridian, township, range, section, and quarter-quarter section (MTRSQQ) centroids. Information on well construction was compiled from California Department of Water Resources Well Completion Reports (CDWR-WCR) included with the PDFs located on the KCPHSD website, or located on the CDWR Well Completion Reports Map Application website. Well construction from CDWR-WCRs was available for 53 of the 71 wells. For one well (Dataset_ID 5), a WCR could not be located, however, well construction information was available in the EWMA GSP. Data were manually compiled into two separate files described as follows: 1) a summary data file that includes well identifiers, location, construction, the number of chemistry samples, the period of record, specific sample dates for each site, and an inventory of which constituent groups were sampled on each date; and 2) a data file of geochemistry analyses for selected constituents classified into one of the following groups: water-quality indicators, major and minor ions, nutrients, trace elements, naturally occurring radioactive material (NORM), and volatile organic compounds (VOCs). Ion (charge) balance calculations and percent error of these calculations were included for samples having a complete suite of major ion analyses. Parameter code, analytical method, reporting level, reporting level type, and supplemental notes were included where available or pertinent. A data dictionary was created to describe the geochemistry data file and is provided with this data release.

The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board compiled and analyzed data for the purpose of mapping groundwater salinity in selected oil and gas fields in California. The data for the Fruitvale and Rosedale Ranch oil fields include well construction data, digitized borehole geophysical data, geochemical analyses of water samples from oil and gas wells and groundwater wells, geological formation depths, and the groundwater total dissolved solids (TDS) calculations used in an accompanying manuscript. These data have been compiled from many sources and span several decades. The well construction data includes attributes such as the date drilling began (spud date), well depth, the depth of top producing perforation, and borehole orientation. These data have been in archived scanned pages in raster format on the Division of Oil, Gas, and Geothermal Resources (DOGGR) website. Similarly, the borehole geophysical data, measured by oil companies, has been archived in raster format. This project has converted the borehole geophysical data from selected oil and gas wells into a computer readable numerical format. The geochemical analyses have also been archived in scanned formats, but now have been compiled into numerical datasets in additional data releases by Metzger and others (2018) and Gans and others (2018). All of the data compiled and analyzed are part of the California State Water Resources Control Board's Program of Regional Monitoring of Water Quality in Areas of Oil and Gas Production and the USGS California Oil, Gas, and Groundwater (COGG) program.