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3.0 SUl3.SURI''A(T INVES'11GATION <br /> 3.1 Soillnvestigation <br /> A SRI•: Field Ilydrogeologist supervised the placement of the three monitoring wells. Turner <br /> Explorations Inc-, was retained to perform drilling services using a rotary drill rig equipped with <br /> hollow stem augers. "Ilic augers were steam cleaned before each monitoring well was installed. <br /> Soil samples were collected at 5-foot intervals during the installation of each monitoring well <br /> using a California split-spoon sampler lined with brass tubes. The sampler and brass tubes were <br /> pre-cleaned before each sampling event using non-phosphate soap, then rinsed with dcionized <br /> j water. All cuttings and samples were collected for logging and testing for organic vapors using <br /> a Thermo Environmental Instruments 580A organic vapor meter(OVM). No odors or petroleum <br /> soil staining were observed in any of the soil samples. OVM readings were less than 1 ppm. <br /> Copies of the field drilling logs are provided in Appendix D. All geological exploration and <br /> } , reporting was completed under the direct supervision of a SRK geologist registered in California <br /> (Gregory W. Knell, California Registered Geologist No. 4692). <br /> The brass tube ends were covereu .;pith aluminum foil,capped with plastic end caps,wrapped with <br /> duct tape, and stored in an iced cooler. Analytical soil samples were selected during the boring <br /> of each monitoring well at depths of 30 feet (seasonal high groundwater level) and 50 feet <br /> (capillary fringe at the current groundwater level) and submitted to a California certified <br /> laboratory for analysis. The analytical soil samples were placed in a cooler containing additional <br /> frozep_ blue ice packets, and shipped following chain-of-custody procedures to North Creek <br /> Analytical (CLAP # 1267) for analysis. The analytical soil parameters include total petroleum <br /> hydrocarbons(TP1-I)as gasoline(Modified EPA Method 8015);benzene,toluene,ethylbenzene, <br /> and xylene (BTEX) (EPA Method 8020); and total lead(EPA Method 7421). <br /> 3.2 Monitoring Well Installation <br /> The three groundwater monitoring wells were installed approximately ten feet into the <br /> groundwater aquifer. The well locations are provided in Figure 1. Groundwater was encountered <br /> at a depth of 5o feet BGS during drilling activities- The screened interval consists of 2-inch <br /> diameter Schedule 20 PVC casing 10.02 slot)that extends from the end of hole to five feet above <br /> the groundwater surface. Blank 2-inch diameter Schedule 20 PVC casing extends from the <br /> screened interval to the ground surface. The sand pack(#2 grade)extends from the bottom of <br /> the boring to live feet above the screened interval. A pelletized bentonite seal(2 feet thick)lies <br /> directly above the sand pack. The remainder of the annular space is filled with grout. A locking <br /> end cap was placed at the top of each casing. The wells are protected at the ground surface with <br /> flush mounted steel Christy boxes set in concrete. Monitoring well construction diagrams and <br /> ing logs are provided in Appendix D. <br /> corresponding drill <br /> Slerrco RcAxruoa and rjmlen - <br /> s�wawr�awvaauia. - <br />