This dataset contains geochemical and other information for 40 historical samples of produced water from the North Coles Levee Oil Field. Three of these samples are from commingled tanks containing produced water from multiple wells as noted in the “Remarks” column. Water that is produced as a byproduct of oil production is called produced water. The numerical water chemistry data were compiled by the U.S. Geological Survey (USGS) from scanned laboratory analysis reports available from the California Geologic Energy Management Division (CalGEM). Sample site characteristics, such as well construction details, were attributed using a combination of information provided with the scanned laboratory analysis reports and well history files from CalGEM Well Finder. The data were transferred manually into a numerical dataset and organized by specific produced water chemical characteristics. Each sample is identified by its API (American Petroleum Institute) number, latitude and longitude, well name, formation name, perforation interval, and date tested. The geochemical analyses include major ions, some minor ions, total dissolved solids (TDS), pH, specific gravity, resistivity, electrical conductivity, and charge balance. The collection and analysis methods and circumstances under which the historical samples were collected cannot be fully known. The intent is to use these historical data in grouped analysis including many sample results, rather than detailed interpretation of each individual sample. Caution should be used in basing interpretations of the data on single sample results.

This dataset contains geochemical and other information for 204 samples of produced water from the Fruitvale petroleum field. Produced water is water coexisting with oil and gas. The historical produced water chemistry data was compiled from preexisting datasets and scanned images into a numerical dataset to characterize produced water chemical characteristics. Each sample is identified by its API (American Petroleum Institute) number, excluding the state code, which is 04 in all California wells, latitude and longitude, well name, formation name, perforation interval, and date tested. The geochemical analyses include major ions, some minor ions, total dissolved solids (TDS), pH, specific gravity, resistivity, electrical conductivity, and charge balance.

This dataset contains geochemical and other information for 204 samples of produced water from the Fruitvale petroleum field. Produced water is water coexisting with oil and gas. The historical produced water chemistry data was compiled from preexisting datasets and scanned images into a numerical dataset to characterize produced water chemical characteristics. Each sample is identified by its API (American Petroleum Institute) number, excluding the state code, which is 04 in all California wells, latitude and longitude, well name, formation name, perforation interval, and date tested. The geochemical analyses include major ions, some minor ions, total dissolved solids (TDS), pH, specific gravity, resistivity, electrical conductivity, and charge balance.

This dataset contains geochemical and other information for 340 samples of produced water from the Elk Hills Oil Field. Water that is produced as a byproduct of oil production is called produced water. The publicly available produced water chemistry data was compiled by USGS staff using historical DOGGR datasets and scanned images. The data were transferred manually into a numerical dataset and organized by specific produced water chemical characteristics. Each sample is identified by its API (American Petroleum Institute) number, latitude and longitude, well name, formation name, perforation interval, and date tested. The geochemical analyses include major ions, some minor ions, total dissolved solids (TDS), pH, specific gravity, resistivity, electrical conductivity, and charge balance.

This dataset contains geochemical and other information for 340 samples of produced water from the Elk Hills Oil Field. Water that is produced as a byproduct of oil production is called produced water. The publicly available produced water chemistry data was compiled by USGS staff using historical DOGGR datasets and scanned images. The data were transferred manually into a numerical dataset and organized by specific produced water chemical characteristics. Each sample is identified by its API (American Petroleum Institute) number, latitude and longitude, well name, formation name, perforation interval, and date tested. The geochemical analyses include major ions, some minor ions, total dissolved solids (TDS), pH, specific gravity, resistivity, electrical conductivity, and charge balance.

This dataset contains geochemical and other information for 268 samples of produced water from the Lost Hills and North and South Belridge Oil Fields. Produced water is water coexisting with oil and gas. The historical produced water chemistry data was compiled from preexisting datasets and scanned images into a numerical dataset to characterize produced water chemical characteristics. Each sample is identified by its API (American Petroleum Institute) number, excluding the state code, which is 04 in all California wells, latitude and longitude, well name, formation name, perforation interval, and date tested. The geochemical analyses include major ions, some minor ions, total dissolved solids (TDS), pH, specific gravity, resistivity, electrical conductivity, and charge balance.

This dataset contains geochemical and other information for 268 samples of produced water from the Lost Hills and North and South Belridge Oil Fields. Produced water is water coexisting with oil and gas. The historical produced water chemistry data was compiled from preexisting datasets and scanned images into a numerical dataset to characterize produced water chemical characteristics. Each sample is identified by its API (American Petroleum Institute) number, excluding the state code, which is 04 in all California wells, latitude and longitude, well name, formation name, perforation interval, and date tested. The geochemical analyses include major ions, some minor ions, total dissolved solids (TDS), pH, specific gravity, resistivity, electrical conductivity, and charge balance.

The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board compiled and analyzed historical produced water chemistry data and ancillary oil well information at the Buena Vista, McKittrick, and Cymric Oil Fields in the southwestern San Joaquin Valley (SWSJV), Kern County, California. Historical water chemistry data provide information on the salt mass balance of produced water disposed of on land, and in particular, chloride which is a conservative, nonreactive tracer. Data were compiled from the California Geologic Energy Management Division (CalGEM) Underground Injection Control (UIC) scans of laboratory results for produced water samples, the CalGEM Well Finder database for oil and gas wells, and historical documents (Rogers, 1917; WZI; 1988). The SWSJV_geochem.csv dataset supplements previously compiled chemistry data by the USGS at the Midway-Sunset, Elk Hills, North Belridge, South Belridge, and Lost Hills Oil Fields (cross-referenced in this data release). The Fall1953_volumes_chemistry.csv dataset contains Fall 1953 water production volumes by lease and produced water sample results compiled from Rickett and Reaves (1954a-d) to provide a spatial understanding of historical disposal on land.

The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board compiled and analyzed historical produced water chemistry data and ancillary oil well information at the Buena Vista, McKittrick, and Cymric Oil Fields in the southwestern San Joaquin Valley (SWSJV), Kern County, California. Historical water chemistry data provide information on the salt mass balance of produced water disposed of on land, and in particular, chloride which is a conservative, nonreactive tracer. Data were compiled from the California Geologic Energy Management Division (CalGEM) Underground Injection Control (UIC) scans of laboratory results for produced water samples, the CalGEM Well Finder database for oil and gas wells, and historical documents (Rogers, 1917; WZI; 1988). The SWSJV_geochem.csv dataset supplements previously compiled chemistry data by the USGS at the Midway-Sunset, Elk Hills, North Belridge, South Belridge, and Lost Hills Oil Fields (cross-referenced in this data release). The Fall1953_volumes_chemistry.csv dataset contains Fall 1953 water production volumes by lease and produced water sample results compiled from Rickett and Reaves (1954a-d) to provide a spatial understanding of historical disposal on land.

This digital dataset contains historical geochemical and other information for 271 samples of produced water from 143 sites in or near the San Ardo Oil Field in Monterey County, central California. Produced water is a term used in the oil industry to describe water that is produced from oil wells as a byproduct along with the oil and gas. The locations from which these historical samples have been collected include 101 wells; three wells (DataSet_ID 118 ,125, and 130) are located outside of the administrative boundary, but closer to San Ardo (within 3 miles) than any other oil field, and therefore they were included in this dataset. Well depth, perforation depths, and (or) depths referred to on geochemistry reports as interval of zone produced, are available for 97 of these wells. Additional sample sites include 11 storage tanks, and 31 unidentifiable sample sources. Designated well use and sample descriptions provide further insight about what the samples represent. The well use designation of most of the wells (79) is OG (oil/gas) and the samples (188) associated with these wells represent produced water. Samples from two wells (Dataset ID 28 and 130) are described as formation water. One well (Dataset ID 30) was drilled as a water-source well (WS) and used to supply groundwater in support of oil production at the time it was sampled, but later converted to an injection well. Another well (Dataset ID 103) was originally drilled as an oil well, but later abandoned and converted to an irrigation well prior to sampling. Eighteen wells have a site type designation of "injectate" based on the sample description combined with the designated well use at the time of sample collection (SF, steam flood; WD, water disposal; or WF, water flood). Most of the historical samples associated with injectate sites may represent water that originated from sources other than the wells at which they were collected. However, samples from two of these wells (Dataset ID 16 and 76) likely represent produced water as they were sampled prior to the wells being used for injection. Limited information is available about historical samples from storage tanks and unidentifiable sample sources, but these may represent pre- or post-treated composite samples of produced water from single or multiple wells. The numerical water chemistry data were compiled by the U.S. Geological Survey (USGS) from scanned laboratory analysis reports available from the California Geologic Energy Management Division (CalGEM). Sample site characteristics, such as well construction details, were attributed using a combination of information provided with the scanned laboratory analysis reports and well history files from CalGEM Well Finder. The compiled data are divided into two separate data files described as follows: 1) a summary data file identifying each site by name, the site location, basic construction information, and American petroleum Institute (API) number (for wells), the number of chemistry samples, period of record, sample description, and the geologic formation associated with the origin of the sampled water, or intended destination (formation into which water was to intended to be injected for samples labeled as injectate) of the sample; and 2) a data file of geochemistry analyses for selected water-quality indicators, major and minor ions, nutrients, and trace elements, parameter code and (or) method, reporting level, reporting level type, and supplemental notes. A data dictionary was created to describe the geochemistry data file and is provided with this data release.