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Page 3 <br />Earth Tech will employ a C-57 licensed water well driller, En Prob Environmental Probing (its <br />LCD and Insurance certification are attached), to advance up to 12 borings at the sites using <br />direct push technology (DPT). The exact locations of the proposed borings will be determined in <br />the field, and are generally located on the attached Figure 1 and Figure 2. The DPT method <br />employs a hydraulic percussion hammer to drive and advance casing through soil. Dual tube <br />(hollow stem, 1.125-inch diameter) casing will be driven to approximately 12 feet below ground <br />surface (bgs) and continuous soil samples will be collected within acetate sleeves. Selected <br />depth-specific samples and groundwater samples will be submitted for chemical analyses. <br />All drilling activities will be directed by an Earth Tech geologist who is, or is under the <br />supervision of, a State of California Registered Geologist. A detailed log of the field activities <br />and observances will be maintained by the site geologist. <br />Subsurface soil will be examined for lithologic identification. The soil will be logged using the <br />Unified Soil Classification System (ASTM D-2487). Subsurface soil will also be screened for <br />organic vapors, as drilling progresses, by use of an organic vapor meter (OVM). <br />At total depth of hole, a one-inch diameter PVC screen will be placed in each DPT hole and one <br />reconnaissance groundwater sample will be collected at each DPT location by using a disposable <br />Teflon bailer or re-usable stainless steel bailer. It is estimated that groundwater will be <br />encountered at approximately 10 feet bgs. <br />Collected DPT groundwater samples will be marked with an identification number, and <br />immediately placed in an insulated container cooled with ice. Reconnaissance groundwater <br />samples will be submitted to a State-certified analytical laboratory, under proper chain-of-custody <br />protocol, for analyses of VOCs (both Site 1 and Site 2) by EPA Method 8260B, TPPH (both Site <br />1 and Site 2) by USEPA Method 8015B, and CAM/CCR 17 Metals (Site 2 only) by EPA <br />6010B/200.7. All analyses will be performed on a standard two week laboratory response time. <br />DPT boreholes will be abandoned after drilling, and after soil and reconnaissance groundwater <br />sampling has been completed, using a concrete or cement slurry tremied from the bottom of the <br />hole to the top by using the one-inch diameter PVC screen as the tremie pipe.