Chemical and isotopic data for water co-extracted with hydrocarbons in oil gas fields are commonly used to examine the source of formation possible impacts on groundwater areas development. Understanding geochemical variability oil-field could help evaluate its origin delineate contamination shallow aquifers cases where is released environment. Here we report multiple isotope (H, C, O, Sr, Ra) from 22 wells, three sources produced that disposed injection two surface disposal ponds four...

Geochemical data from 40 water wells were used to examine the occurrence and sources of radium (Ra) in groundwater associated with three oil fields California (Fruitvale, Lost Hills, South Belridge). 226Ra+228Ra activities (range = 0.010-0.51 Bq/L) exceeded 0.185 Bq/L drinking-water standard 18% (not wells). Radium correlated TDS concentrations (p < 0.001, ρ 0.90, range 145-15,900 mg/L), Mn + Fe 0.82, <0.005-18.5 pH -0.67, 6.2-9.2), indicating Ra was influenced by salinity, redox, pH....

Abstract Growing water stress has led to emerging interest in protecting fresh and brackish groundwater as a potential supplement supplies raised questions about factors that could affect the future quality of aquifers. Limited well infrastructure, particularly regions where elevated salinity limited historical development, hinders traditional mapping distributions through sampling. This paper presents quantitative approach upper 300 m using high‐resolution, regionally comprehensive...

Mature oil fields potentially contain multiple fluid migration pathways toward protected groundwater (total dissolved solids, TDS, in nonexempted aquifer <10,000 mg/L) because of their extensive development histories. Time-series data for water use, pressures, oil-well construction, and geochemistry from the South Belridge Lost Hills mature California are used to explore roles injection/production oil-field well-integrity issues migration. Injection/production modified hydraulic gradients...

First posted July 20, 2018 For additional information, contact: Director,California Water Science CenterU.S. Geological Survey6000 J Street, Placer HallSacramento, California 95819 The State Resources Control Board initiated a regional monitoring program in 2015 to determine where and what degree groundwater quality may be adversely impacted by oil gas development activities. A key issue the implementation of is that each year, detailed characterization work can done only few California’s...

Groundwater samples collected from irrigation, monitoring, and municipal supply wells near the Oxnard Oil Field were analyzed for chemical isotopic tracers to evaluate if thermogenic gas or water hydrocarbon-bearing formations have mixed with surrounding groundwater. New historical data show no evidence of in groundwater overlying field. However, microbial methane was detected 5 at concentrations ranging 0.011–9.1 mg/L. The presence these gases <10 mg/L do not indicate degraded quality...

Groundwater samples have been collected in California as part of statewide investigations groundwater quality conducted by the U.S. Geological Survey for Ambient Monitoring and Assessment (GAMA) Priority Basin Project (PBP). The GAMA-PBP is being cooperation with State Water Resources Control Board to assess monitor resources used drinking-water supply improve public knowledge California. Quality-control (source-solution blanks, equipment field blanks) were order ensure sample results. Olsen...

First posted December 9, 2016 Revised November 21, 2017 For additional information, contact: Director, California Water Science CenterU.S. Geological Survey 6000 J Street, Placer Hall Sacramento, 95819 Exploratory sampling of groundwater in coastal Los Angeles County and Kern Kings Counties the southern San Joaquin Valley was done by U.S. from September 2014 through January 2015 as part State Resources Control Board's Quality Areas Oil Gas Production Regional Groundwater Monitoring Program....

Noble gases record fluid interactions in multiphase subsurface environments through fractionation processes during equilibration. Water the presence of hydrocarbons at acquires a distinct elemental signature due to difference solubility between these two fluids. We find atmospheric noble gas produced water is partially preserved after production and disposal unlined ponds surface. This from meteoric can be used trace oil-field seepage into groundwater aquifers. analyse (n = 30) pond 2)...

Santa Barbara County, California, USA. To analyze a wide array of newly collected chemical, isotopic, dissolved gas, and age dating tracers in conjunction with historical data from groundwater oil wells to determine if water and/or thermogenic gas oil-bearing formations have mixed the Orcutt Oil Field surrounding area. Three 15 samples had compositions indicating potential mixing formations. Relevant indicators included salinity (TDS, Cl, Br), NH3, DOC, enriched δ13C-DIC, δ2H-CH4, δ13C-CH4,...

First posted February 6, 2023 For additional information, contact: Director, California Water Science CenterU.S. Geological Survey6000 J Street, Placer HallSacramento, 95819 Groundwater quality and potential sources migration pathways of chemical constituents associated with hydrocarbon-bearing formations were assessed by the U.S. Survey for State Resources Control Board Oil Gas Regional Monitoring Program (RMP). samples collected as part RMP from 21 preexisting wells used public supply,...

Abstract The variables affecting the occurrence of hydrocarbons in aquifers used for public supply California were assessed based on statistical evaluation three large statewide datasets; gasoline oxygenates also analyzed comparison with hydrocarbons. Benzene is most frequently detected (1.7%) compound among 17 at generally low concentrations (median concentration 0.024 μg/l) groundwater California; methyl tert‐ butyl ether ( MTBE ) (5.8%) seven 0.1 μg/l). At aquifer depths supply, and...

Relative risks of groundwater-quality degradation near selected California oil fields are estimated by examining spatial and temporal patterns in chemical isotopic data the context groundwater-age categories defined tritium carbon-14. In Coastal basins, western San Joaquin Valley (SJV), eastern SJV; 82, 76, 0% samples premodern (pre-1953 recharge), respectively; 3, 0, 31% modern (recharged during or after 1953), respectively. Carbon-14 helium-4 indicate most 1000 to 10,000 (33%) >10,000...

First posted September 1, 2016 Revised January 17, 2017 For additional information, contact: Director, California Water Science Center U.S. Geological Survey 6000 J Street, Placer Hall Sacramento, CA 95819 http://ca.water.usgs.gov Groundwater quality in the 3,016-square-mile Monterey–Salinas Shallow Aquifer study unit was investigated by (USGS) from October 2012 to May 2013 as part of State Resources Control Board Ambient Monitoring and Assessment (GAMA) Program's Priority Basin Project. The...

First posted October 3, 2016 For additional information, contact: Director, California Water Science Center U.S. Geological Survey 6000 J Street, Placer Hall Sacramento, 95819 http://ca.water.usgs.gov Groundwater quality in the 48-square-mile Santa Barbara study unit was investigated 2011 as part of State Resources Control Board’s Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project. The is mostly County Transverse Selected Peninsular Ranges hydrogeologic province. GAMA...

Groundwater quality in the 48-square-mile Santa Barbara study unit was investigated by U.S. Geological Survey (USGS) from January to February 2011, as part of California State Water Resources Control Board (SWRCB) Ambient Monitoring and Assessment (GAMA) Program’s Priority Basin Project (PBP). The GAMA-PBP developed response Quality Act 2001 is being conducted collaboration with SWRCB Lawrence Livermore National Laboratory (LLNL). thirty-fourth be sampled GAMA-PBP. GAMA designed provide a...

Groundwater resources are utilized near areas of intensive oil and gas development in California’s San Joaquin Valley. In this study, we examined chemical isotopic data to assess if thermogenic or saline water from producing formations have mixed with groundwater the Elk Hills North Coles Levee Oil Fields southwestern Major ion concentrations stable isotope compositions were largely consistent natural processes, including mixing different recharge sources water-rock interactions. Trace...

Groundwater quality in the 2,400-square-mile Santa Cruz, San Gabriel, and Peninsular Ranges Hard Rock Aquifers (Hard Rock) study unit was investigated by U.S. Geological Survey (USGS) from March 2011 through 2012, as part of California State Water Resources Control Board (SWRCB) Ambient Monitoring Assessment (GAMA) Program’s Priority Basin Project (PBP). The GAMA-PBP developed response to Quality Act 2001 is being conducted collaboration with SWRCB Lawrence Livermore National Laboratory...

First posted October 3, 2016 For additional information, contact: Technical reports and hydrologic data collected for the GAMA Program may be obtained fromGAMA Project ChiefU.S. Geological SurveyCalifornia Water Science Center6000 J Street, Placer HallSacramento, CA 95819Telephone number: (916) 278-3100WEB: http://ca.water.usgs.gov/gamaGAMA Unit ChiefState Resources Control BoardDivision of QualityPO Box 2231, Sacramento, 95812Telephone 341-5779WEB:http://www.waterboards.ca.gov/gama...