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. the existing and proposed well locations to allow for access to a remediation system The proposed well locations were set with surface vaults to allow access for future drilling In early June 1995, the proposed drilling program was completed Groundwater monitoring wells TBI and TB 10 were installed along the western side of the site to further define the upgradient quality of groundwater These wells are constructed of 2-inch diameter PVC Wells TB7 and TB8 are located within the dissolved groundwater plume, and are constructed of 4-inch diameter PVC These wells are designed for use in a groundwater pumping program Vapor well TB3 was installed in the location of boring TB3 and was completed to a depth of 50 feet below grade The well is screened from total depth to 5 feet below grade Wells TB9, TB 11, and TB 12 are nested vapor extraction wells that include two discrete well casings Each has a deep well that is screened from 60 feet to 35 feet and a shallow well that is screened from 30 feet to 5 feet below grade These wells are located within the former tank area and may be used to selectively treat shallow or deep soils The wells are constructed of 2-inch diameter PVC Additionally, one hand auger boring (TBS) was drilled adjacent to the eastern pump island Also, well MW3R, which • was damaged during site construction, was re-drilled and replaced with new well casing Well MW3 was also abandoned at this time Groundwater monitoring wells TBI, MW3R, and TB 10 were installed to 70 feet bgs and are constructed of 2-inch diameter PVC Wells TBI and MW3R are screened from total depth to approximately 40 feet bgs Well TB 10 was screened from total depth to 20 feet bgs to allow access for future vapor extraction should this become necessary Wells TB7 and TB8 are 4 inches in diameter and are screened from total depth to 25 feet and 45 feet, respectively Each well installed at the site (vapor or groundwater) is constructed with 0 02 inch slotted PVC as the screen material The filter pack for each well consists of #3 Monterey sand The wells were sealed with approximately 3 feet of bentonite pellets on top of the sand pack and were grouted from the top of the seal to the surface with neat cement using the tremmie method All well sealing procedures were overseen by PHS/EHD personnel Each well is covered with a traffic- rated vault and sealed with a watertight locking cap Further details on drilling and well i Page 5