Produced water chemistry data for the Lost Hills, Fruitvale, and North and South Belridge study areas, Southern San Joaquin Valley, California (version 1.1, September 2020)

The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (Water Board) collected produced water and casing gas samples from petroleum wells and other oil-field sites in selected oil fields in the southern San Joaquin Valley in Kern County in 2016 and 2017. The samples were collected as part of the Water Boards Regional Groundwater Monitoring Program (RMP) of Water Quality in Areas of Oil and Gas Production. Samples included produced water and casing gas collected from oil wells, produced water collected from surface produced water disposal ponds, and injectate stored in tanks planned for underground injection. Samples were collected from the Fruitvale oil field on July 26th and July 27th, 2016. Samples were collected from the Lost Hills oil field on October 12th and October 13th, 2016. Samples were collected from the North Belridge oil field on July 25, 2017. Samples were collected from ponds near the South Belridge oil field on October 12, 2017. 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 ions, and nutrients; concentrations of dissolved organic constituents; dissolved organic carbon and optical characteristics; and stable isotopes of water and solutes dissolved in water. Samples were analyzed in the field and by twelve laboratories operated or contracted by the USGS.