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r <br /> r SECTION 1.0 INTRODUCTION <br /> Task 1 —Survey of Public and Private Groundwater Wells <br /> At the February 10, 1999 meeting, the CVRWQCB requested a survey of public and private <br /> groundwater wells within 500 feet of Shop 10 In addition, URSGWC proposed to review public <br /> well records maintained by the California Department of Water Resources (CDWR) and conduct <br /> a survey of well owners within 500 feet of the Shop 10 site <br /> Task 2—Vertical Delineation of Petroleum Hydrocarbons in Groundwater <br /> The CVRWQCB requested that the vertical extent of petroleum hydrocarbons in groundwater be <br /> evaluated for the Shop 10 site To delineate the vertical distribution of petroleum hydrocarbons in <br /> groundwater, the KabisTm discrete groundwater sampler was proposed Wells MW-13 (screened <br /> from approximately 65 to 90 feet bgs), MW-14 (screened from approximately 65 to 85 feet bgs) <br /> and VM-2 (screened from approximately 15 to 60 feet bgs) were proposed to be sampled using <br /> the KabisTm discrete sampler Two of the wells are 4-inch diameter PVC and one well is 2-mch <br /> diameter PVC These wells are in areas where petroleum hydrocarbons have been historically <br /> detected in groundwater <br /> In the scope of work, groundwater samples were proposed to be collected in each of the wells at <br /> the following locations (1) less than 2 feet from the top of the water table, (2) approximately 10 <br /> feet below the top of the water table, and (3) approximately 15 to 20 feet below the top of the <br /> water table Groundwater was not to be purged from the wells prior to sample collection Rather, <br /> the objective was to collect undisturbed samples (to the extent possible) at up to three sample <br /> depths Groundwater sampling procedures are detailed in Appendix A Literature on the Kabisr"' <br /> discrete sampler is provided as Appendix B <br /> Groundwater samples were proposed to be analyzed for TPH-gasoline range (TPH-g) and <br /> benzene, toluene, ethylbenzene, and total xylenes (BTEX), and methyl tertiary butyl ether <br /> (MTBE) following U S Environmental Protection Agency (EPA) Test Methods 8015 modified <br /> and 8260B, respectively In addition, groundwater samples from the selected monitoring wells <br /> were proposed to be analyzed for nitrate and sulfate Field measurements were collected for pH, <br /> conductivity, temperature, and dissolved oxygen in groundwater <br /> Task 3 —Estimation of Hydraulic Conductivity <br /> To estimate the hydraulic conductivity beneath Shop 10, slug tests were proposed in up to three <br /> monitoring wells The slug tests entailed measuring the instantaneous response within the <br /> respective wells after introducing and removing a mandrel (slug) of specified weight and volume <br /> Water elevation data were collected over specified time intervals until static conditions were <br /> . achieved Standard procedures for the slug tests are presented in Appendix C <br /> S 1PROJU1040100041SHOP101SHOP10SA.DOC 1-3 UHS Greiner Woodward Clyde <br />