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\ Ms. Linda Turkatte June 11, 1996 Page 3 The ends of the brass tubes containing the soil samples were covered with teflon sheeting, capped with plastic end caps, labeled,and stored in a cooler containing ice. The samples selected for chemical analysis were delivered to Superior Analytical Laboratory (Superior) in Martinez, California, a state-certified laboratory with a completed chain-of-custody record. The soil samples were analyzed for total petroleum hydrocarbons as gasoline(TPHg)and benzene,toluene,ethylbenzene,and xylenes(BTEX)by EPA Methods 8015, modified and 8020,respectively. Grab groundwater samples were collected from soil boring SB-1 and SB-2 locations. After reaching the total depth of.each soil boring, the hollow-stem augers were pulled up approximately five feet to allow groundwater to enter the borehole. The grab groundwater samples were then collected through the augers using a disposable PVC bailer. Collected groundwater samples were transferred directly from the bailer into laboratory-supplied glassware,labeled,sealed in plastic bags,and placed in a cooler containing ice. Samples were transported to Superior along with completed chain-of-custody records and were analyzed-for TPHg and BTEX by EPA Methods 8015,modified and 8020,respectively. Well Installation After advancement to the respective total depths, two boreholes (MW-1. and VE-1) were converted to a groundwater monitoring well and a soil vapor extraction well(Figure 3). Table 1 provides well construction details and elevation data for these newly-installed wells. Detailed well construction,designs are included with the,boring•logs(Attachment A). Groundwater monitoring well MW-I was completed at a depth of 46 feet bgs with 20 feet of capped,:flush- threaded, 2-inch diameter Schedule 40 PVC 0.020-inch machine slotted well screen from the base of the borehole and completed with blank•casing to the surface. Filter sand was placed in the annular space between the wall of the borehole and casing to a height of one and a half feet above the screened interval. One and a half feet of bentonite pellets were placed above the sand and hydrated, A cement-grout mixture (5%bentonite)was placed into the remaining annular space to ground,surface. A flush-mounted,protective water-tight monument,cover was then grouted slightly. above ,ground surface to complete the well installation. The well was also fitted with a locking watertight well cap, Vapor extraction well VE-1 was completed at a depth of 35 feet bgs after backfilling with filter sand from 37 feet bgs. The well was completed with 20 feet of capped,flush-threaded, 4-inch diameter Schedule 40 PVC 0.020-inch machine slotted well screen and completed with blank casing to the surface. Filter sand was placed in the annular-.space between the wall of the borehole and casing to a height of two feet above the screened interval. One foot of bentonite pellets was placed above the sand and hydrated. A cement grout mixture(5%bentonite).was placed into the remaining annular space to ground surface. A flush-mounted, protective water-tight monument cover was then grouted slightly above ground surface to complete the well installation. The well was also fitted with a locking water-tight well cap. Well Surveying,Development and Sampling Monitoring wells MW-1 (SFFBC well),MW-6,MW-8,and MW-14(Texaco wells)were surveyed for top- of-casing and ground surface elevation by Ron Archer Civil Engineering(RACE)of Pleasanton, California. The reference datum used for surveying was from Texaco monitoring well MW-14 that was taken as 9.53 HASUBMILL.RPT 50090-011.02