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MW-6 were advanced to a depth of 85 feet and completed as groundwater monitoring wells Borings B7 and B8 were advanced to a depth of 65 feet and backfilled in the entire depth with Portland cement No petroleum hydrocarbons were detected in any of the 14 soil samples analyzed The stratigraphy appears to vary considerably acioss the site Clayey to sandy silts are present from the surface to depths of 6 to 12 feet The silt overlies moderately-sorted to well-sorted sand, which extends to depths of 25 to 30 feet in all borings Below 30 feet, the dominant lithology is sand in all borings A relatively widespread clay to clayey silt lens is present between 35 to 40 feet in several bonngs The base of the sand occurs at 78 feet in MW-5. Greenish gray silt is present to the bottom of boring MW-5 at 85 feet The depth to groundwater ranged from 72 to 73 feet fjom January to May 1994 The calculated elevation of this surface was anomalously low in MW-5 during all three monitoring events The gradient ranged from 0 003 ft/ft to 0 0075 ft/ft directed southwest These gradients are more shallow than the previous gradient of 0 05 ft/ft directed westward (November 1992) During the January 1994 monitoring event, TPH as gasoline was detected in MW-2 at 85 ppb, traces of benzene were detected in samples from MW-2 and MW-6, traces of toluene were detected in MW-2 and MW-5 During the May 1994 monitoring, TPH as gasoline was detected in MW-2 ata concentiation of 230 ppb No petioleuin hydiocaibons were detected in any other well during the May 1994 monitoring 2.6 Soil Disposal On May 11, 1994, 17 drums of soil were removed from the site and transported to 11490 North Alpine Road The drums contained auger returns from borings MW-5, MW-6, B-7 and B-8 Analytical results from these borings indicated that the soil was not impacted by Ipetroleum hydrocarbons The soil was spread next to the driveway near the residence at 11490 North Alpine Road I 3.0 PROCEDURES I3.1 Groundwater Extraction Test On November 21, 1994, an extended purge was peifoinied on MW-2 in an attempt to remove the limited impacted gioundwater The deptli-to-gioundwaterwas measured in each well ielative to the top of the casing using a Solinst water level meter (Table 2) A submeisible pump was then used to puige MW-2 A iegeneiative blower was connected to the well head and a vacuum was applied duiing pumping to increase well recharge Due to limited water column and slow rechaige, only 200 gallons of water were removed in approximately 7 hours Purge water was stored on-site in 55-gallon drums �VftI A.&I k.. 5 UW fwd H..m.OR7:k1 W.W&S