Revision History for Open-File Report 2016–1181 David B. Dillon, Tracy A. Davis, Matthew K. Landon, Michael T. Land, Michael T. Wright, and Justin T. Kulongoski Data from Exploratory Sampling of Groundwater in Selected Oil and Gas Areas of Coastal Los Angeles County and Kern and Kings Counties in Southern San Joaquin Valley, 2014–15: California Oil, Gas, and Groundwater Project ----------------------------------------------------- Posted online December 9, 2016 ----------------------------------------------------- Revised and reposted November 2017, version 1.1 Changes were made to the text and 4 tables because the original data was given in an incorrect format which compounded an error in table 13. Specifically, the following changes were made: Page 13, First paragraph after heading "Collection of Blank Samples" - A sentence changed from "Organic-free water, purged with nitrogen gas, was used for blanks of organic constituents (VOCs, SVOCs, PAHs, DOC, UV absorbance, and dissolved hydrocarbon gases)..." to "Organic-free water, purged with nitrogen gas, was used for blanks of organic constituents (VOCs, SVOCs, PAHs, DOC, and UV absorbance)..." A sentence changed from "Blanks were not collected for tritium activity, dissolved noble gases, dissolved standard gases, or carbon-14..." to "Blanks were not collected for tritium activity, dissolved noble gases, dissolved standard and hydrocarbon gases, or carbon-14..." Page 15, Paragraph before heading "Replicates" deleted - Dissolved hydrocarbon gases analyzed by Isotech Laboratories, Inc., were each detected in at least one blank from the WRD Grundfos pumps, whereas only methane and dissolved methane were detected in the other blanks (table A–2A). Concentrations of ethane, methane, and dissolved methane detected in blanks were several orders of magnitude less than the concentrations detected in the COGG groundwater samples, so were not considered meaningful. The detection of dissolved ethane in the blank sample from the WRD Grundfos pumps was very near the reporting level, so was not considered meaningful. Page 17, Third paragraph on left text column - The paragraph changed from "Of the 20 dissolved analyzed hydrocarbon and standard gas constituents, 14 individual gases were detected in 34 replicate samples, and all but 1 were within acceptable range. Oxygen was the only constituent out of range (11.70 mole percent and 9.44 mole percent), which was barely out of acceptable precision with an RSD of 11 percent (table A–3A)" to "Of the 19 dissolved analyzed hydrocarbon and standard gas constituents, 14 individual gases were detected in 40 replicate samples, and 4 samples were out of acceptable range. There were two pairs out of range for oxygen (1.58, 1.16 mole percent; 11.70, 9.44 mole percent), and one replicate pair for methane (1.54, 2.29 mole percent) and dissolved methane (0.19, 0.28 mg/L; table A–3A). No actions were taken in censoring data." Page 17, Last sentence of fourth paragraph on left text column - Sentence changed from "Four isotopes of dissolved standard and hydrocarbon gases (δ13C of methane, ethane, and δ2H of methane) were analyzed, composing six samples in total. All samples were within acceptable precision." to "Four isotopes of dissolved standard and hydrocarbon gases (δ13C of methane, ethane, and propane (per mil); and δ2H of methane (per mil)) were analyzed, composing eight samples in total. One replicate pair of δ2H of methane was out of acceptable range (-215.4, -220.2 per mil), and no actions were taken in censoring data." Table 11 from ofr20171181_ver_1.1.xlsx - Units for Carbon-14 changed from pM to pMc. Table 13 from ofr20171181_ver_1.1.xlsx - Corrected various values in rows LA_3 to LA_6. Table A2A from ofr20171181_ver_1.1.xlsx - Deletion of hydrocarbon and standard gases section in table A2a-blanks. Table A3B from ofr20171181_ver_1.1.xlsx - Addition of a isotopic hydrocarbon replicate in table A3b-isotopes.