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Boring Permit Application TRACY HILLS SITE — PROPOSED ELEMENTARY SCHOOL WKA No. 10137.04P February 22, 2018 Page 4 A surface seal of hydrated powdered bentonite will be installed to surface grade A well monument will be installed at the surface for each boring The temporary soil gas sampling probes will be properly decommissioned subsequent to the Site investigation. WKA will coordinate the services of a 0-57 licensed well driller to properly abandon the soil gas sampling probes in accordance with State and County requirements. The soil gas sampling probes will be destroyed under permit from San Joaquin County by over- drilling the total depth of each boring using appropriate sized hollow-stem augers (along with the well casings in each boring. Each boring will then be pressure grouted using cement grout to surface grade. The augers will be steam cleaned between each boring location. Installation of Groundwater Monitoring Well Two temporary groundwater monitoring wells will be installed at the southern portion of the Site to determine if groundwater would pose a possible vapor intrusion threat. The proposed scope of work for monitoring well installation is as follows: Coordinate with SJCEHD to schedule a grout/well installation inspection; Coordinate with a 0-57 licensed drilling company to advance two soil borings using a truck-mounted drill rig equipped with eight-inch diameter hollow stem augers to depths of approximately 90 feet below ground surface (bgs); Convert the soil borings into two-inch diameter temporary groundwater monitoring wells using 20 feet of 0.01-inch screened two-inch diameter Schedule 40 PVC casing and 80 feet of two-inch diameter Schedule 40 PVC casing, number 2/12 sand up to 78 feet bgs, bentonite (hydrated) from 75 feet bgs to 78 feet bgs, completed with neat cement to surface grade. The wells will be completed with steel locking well monuments. Place soil cuttings in labeled 55-gallon, steel drums and storing the drums at the Site; Survey the location and top-of-casing elevation of the wells to the nearest available benchmark (by a California-licensed Professional Land Surveyor). The temporary soil gas sampling probes and groundwater monitoring wells will be properly decommissioned subsequent to the Site investigation. WKA will coordinate the services of a C- 57 licensed well driller to destroy the soil gas sampling probes and monitoring wells in accordance with State and County requirements. The soil gas sampling probes and monitoring wells will be destroyed under permit from San Joaquin County. The soil gas probes will be destroyed by removing the well boxes, grouting each well using neat cement to approximately three feet bsg then over-drilling the top five feet of each boring probe using appropriate sized hollow-stem augers (along with the well casings in each boring) then covered with native soil to surface grade.