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AdvancedGeo <br />Environmental -0•-gg <br />08 February 2018 <br />AGE Project No. 17-4116 <br />Page 2 of 4 <br />depths of 5 and 15 feet bsg. Samples will be collected from each boring at 5 and 15 feet <br />bsg utilizing a Summa Canister. Proposed boring locations are depicted in Figure 2. <br />Proposed borings will be advanced using a Geoprobe 5400 direct-push probing unit. <br />Samples will be submitted to a California Department of Public Health (CDPH)-Certified <br />laboratory and will be analyzed for: <br />Total petroleum hydrocarbons (TPH) in accordance with EPA Method 8015. <br />Volatile organic compounds (VOCs) in accordance with EPA Method 8260B. <br />PERMITTING AND PRE-FIELD WORK ACTIVITIES <br />Applicable drilling permits will be obtained from the San Joaquin County Environmental <br />Health Department (SJCEHD) and a site-specific Health and Safety Plan will be prepared. <br />Prior to mobilization, the site will be clearly marked and a utility clearance will be obtained <br />through Underground Service Alert. The SJCEHD will be contacted a minimum of two <br />days prior to conducting investigation activities to arrange for grout inspection. <br />FIELD PROCEDURES <br />All field procedures will be overseen by an AGE representative working under the <br />supervision of a California Professional Geologist. Procedures for sample collection and <br />analysis, equipment decontamination and sample handling are presented below. <br />SOIL-VAPOR SAMPLING <br />Soil-vapor samples will be collected from nested (dual-completed) soil-vapor points. For <br />installation of the dual soil-vapor points, a temporary/disposable vapor-tip and 1/4-inch <br />Teflon tubing will be lowered to the base of the borings at approximately 15 feet bsg; two <br />feet of tubing will remain outside the boreholes for vapor sample collection. Once the <br />tubing and vapor-tip are in place, a filter pack of #3 sand will be placed from the bottom <br />of the boreholes to one-foot above the vapor tips. Following placement of the filter pack, <br />one-foot of dry bentonite crumbles will be placed atop the filter packs. Thereafter, <br />bentonite chips will be placed and hydrated to approximately 5 feet bsg. Once the 15-foot <br />soil-vapor point is set, an additional temporary/disposable vapor-tip and 1/4-inch Teflon <br />tubing will be lowered to the base of the borings at approximately 5 feet bsg; two feet of <br />tubing will remain outside the borehole. Once the tubing and vapor-tip are in place, a filter <br />pack of #3 sand will be placed from the bottom of the boreholes to one-foot above the <br />vapor tip. Following placement of the filter pack, dry bentonite crumbles will be place atop <br />the filter pack. Thereafter, bentonite chips will be placed and hydrated to near surface <br />grade to seal the vapor well from ambient air intrusion.