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22 December 2020 AdvancedGeo <br /> Project No. 20-6264 An Employee-ONneECompony <br /> '00Page 4 of 6 V. <br /> Appropriately sealed and labeled samples will be placed in a chilled container under ice <br /> and transported under chain-of-custody procedure to an ELAP-certified laboratory. <br /> Samples will be analyzed for the constituents listed in Section 2.3. Each sample will be <br /> labeled with boring designation, depth, time, date and sampler's initials. Soils <br /> encountered in the borings will be visually classified by AGI personnel in accordance with <br /> the Unified Soil Classification System (USCS). Additionally, soil samples will be field- <br /> screened for presence of volatile organic compounds using an organic vapor meter <br /> (OVM), equipped with photo-ionization detector (PID) pre-calibrated to isobutylene. <br /> 3.1.2 Grab Groundwater Sampling <br /> A grab groundwater sample will be collected from the boring B7 to assess potential <br /> petroleum hydrocarbon impact to groundwater resulting from historical auto repair <br /> activities. For collection of the grab groundwater sample, the soil boring will be advanced <br /> to the top of the groundwater table as identified by collection of a saturated soil sample. <br /> Once groundwater has been encountered, a Geoprobe (or similar) push-driven water <br /> sampling device will be advanced four feet into the water-bearing zone. Grab groundwater <br /> samples will be collected using a Geoprobe water sampling assembly fitted with a pre- <br /> cleaned, one-inch diameter 0.01-slotted temporary well screen. Each groundwater <br /> sample will be extracted by dedicated disposable polyethylene tubing through the hollow <br /> center of the push rods into the screen section. Samples will be analyzed for the <br /> constituents listed in Section 2.3. and will be collected into laboratory-supplied, preserved <br /> 40-ml VOA vials, 1-liter unpreserved amber bottles, and 250-ml polyethylene containers <br /> preserved with nitric acid. Appropriately sealed and labeled samples will be placed in a <br /> chilled container under ice and transported under chain-of-custody procedure to an <br /> ELAP-certified laboratory. Each sample containerwill be labeled with sample designation, <br /> time, date, and sampler's initials. <br /> 3.1.3 Soil-Vapor Sampling &Analysis <br /> At the proposed soil-vapor sampling locations, the borings will be advanced to 5 feet bsg <br /> using a hand tooling. Once the total depth is reached semi-permanent soil-vapor sampling <br /> wells will be installed within the boring. The temporary sampling points will consist of 7 <br /> feet of/4-inch Teflon tubing and a sampling tip (generally inert ceramic stone). Prior to <br /> installing the tubing and sampling stone, #2/12 sand will be poured in the annuals of the <br /> boring for the sample tip to rest on. The tubing and sampling tip will then be lowered to a <br /> depth of five feet bsg and one foot of#2/12 sand will be poured around the tip to create <br /> a filter pack. Above the sand, one foot of dry granular bentonite will be placed to a depth <br /> of 4 feet bsg. Thereafter, hydrated bentonite will be placed from 3 feet bsg to near surface <br /> grade to seal each location and prevent ambient air intrusion during sampling. <br /> A soil-vapor sample will be collected after allowing a minimum of two hours equalization <br /> time following installation of the soil-vapor wells. Prior to soil-vapor sample collection, <br /> three calculated volumes of air will be purged utilizing a 6-liter purge canister and <br />