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AdvancedGeo Environmental :OEN 25 April 2017 AGE-NC Project No. 97-0301 Page 4 of 6 3.1.1. Soil-Vapor Boring Advancement and Sampling Soil borings SV-1 and SV-2 will be advanced utilizing a 4-inch diameter stainless steel hand auger. Upon reaching the total depths, soil borings SV-1 and SV-2 will be converted into semi-permanent soil-vapor point using a three-inch long vapor implant attached to 1/4-inch diameter Teflon tubing. The vapor implant and tubing will be lowered to total depth of the boring (i.e. 6 % feet bsg; filter pack material consisting of #2/12 sand will be placed from the bottom of the borehole to a depth approximately one-foot above the vapor implant (i.e. 5 - 6 '1/2 ft). Following filter placement, approximately 1/2 foot of dry granular bentonite will be placed above the filter pack (i.e. 4 1/2 - 5 ft). The remainder of the void space between the tubing and the open borehole will be filled with a neat cement with 1- 5% bentonite content at depths between 1/2 - 4 1/2 feet bsg. The as-built construction of the soil-vapor sampling well is depicted in Figure 5. 3.1.2. Soil Sampling Soil samples will be collected at 5 feet bsg from soil borings SV-1 and SV-2 utilizing a 4- inch diameter hand auger. Each soil sample will be placed directly into a 6-inch brass sleeve. The exposed ends of each brass sleeve will be covered with Teflon sheets, capped, and sealed with tape. Each soil sample will be visually logged and classified by an AGE geologist in accordance with the Unified Soil Classification System (USCS). Additionally, soil samples will be field screened for the presence of volatile organic compounds using an organic vapor meter (OVM), equipped with a photo-ionization detector (PID). Soil sample descriptions and OVM readings will be recorded on a log for each soil boring. Following sample collection, each preserved sample sleeve will be labeled with the boring location, depth, time, date, and sampler's initials. Appropriately sealed and labeled samples will be placed in a chilled container and transported under chain of custody to a State of California Department of Public Health (CDPH)-certified laboratory. Laboratory reports of soil analysis, testing methods, laboratory quality assurance/quality control (QA/QC) reports, and sample chain of custody documentation will be presented in a report of findings and recommendations. 3.1.3. Soil-Vapor Sampling Following soil-vapor well installations, a 48-hour stabilization period will be observed prior to soil vapor sample collection at each of the vapor point well locations. A one-liter Summa canister and a 6-liter purge canister will be connected together with a dedicated and serialized sampling inlet manifold. The sampling inlet manifold will consist of an air/vapor- tight valve; a particulate filter; a calibrated flow restrictor calibrated to 150 milliliters per minute (ml/min), a stainless steel tee-fitting, two vacuum gauges at either end of the controller and connections for both purge and sampling canisters (manifold assembly).