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07 December 2020 <br />Project No. 20-6249 <br />Page 3 of 6 <br /> Boring abandonment. <br /> Report preparation. <br /> <br /> <br />2.1. PERMITTING AND PRE-FIELD WORK ACTIVITIES <br /> <br />Applicable site assessment drilling permits will be obtained from the EHD. Also, a site- <br />specific Health and Safety Plan will be prepared prior to field work. Prior to mobilization, <br />each soil probe boring location will be clearly marked, and a utility clearance obtained <br />through Underground Service Alert (USA/511). The EHD will be contacted at least 72 <br />hours prior to conducting investigation activities to coordinate a grout inspection. <br /> <br /> <br />2.2. SOIL BORING ADVANCEMENT AND SAMPLING <br /> <br />AGI proposes to advance four (4) soil borings to 20 feet bsg utilizing a van or truck- <br />mounted Geoprobe 5400 direct-push probing unit equipped with 1.25-inch diameter <br />probing rods. The Geoprobe advances soil probe borings using a hydraulic hammer to <br />drive sampling tools to specified depths. <br /> <br />Soil samples will be collected at discrete five-foot intervals beginning at five feet bsg using <br />a 1.45-inch Geoprobe soil sampling assembly loaded with a two-foot acetate liner. Upon <br />sample retrieval, a selected portion of the liner will be cut, and the ends will be covered <br />with Teflon sheets, capped, and sealed with tape. Appropriately sealed and labeled <br />samples will be placed in a chilled container under ice and transported under chain-of- <br />custody procedure to a California Environmental Laboratory Accreditation Program <br />(ELAP)-certified laboratory. Each sample will be labeled with boring designation, depth, <br />time, date and sampler's initials. Soils encountered in the borings will be visually classified <br />by AGI personnel in accordance with the Unified Soil Classification System (USCS). <br />Additionally, soil samples will be field-screened for presence of volatile organic <br />compounds using an organic vapor meter (OVM), equipped with photo-ionization detector <br />(PID) pre-calibrated to isobutylene. <br /> <br />Grab groundwater samples will be collected from each soil boring. Once groundwater has <br />been encountered, a Geoprobe (or similar) push-driven water sampling device will be <br />advanced four feet into the water-bearing zone. Grab groundwater samples will be <br />collected using a Geoprobe water sampling assembly fitted with a pre-cleaned, one-inch <br />diameter 0.01-slotted temporary well screen. Each groundwater sample will be extracted <br />by dedicated disposable polyethylene tubing through the hollow center of the push rods <br />into the screen section. Samples will be collected into laboratory-supplied, preserved 40- <br />ml Volatile Organic Analysis (VOA) vials. Appropriately sealed and labeled samples will <br />be placed in a chilled container under ice and transported under chain-of-custody <br />procedure to an ELAP-certified laboratory. Each sample container will be labeled with <br />sample designation, time, date and sampler's initials.