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At each location, Gregg advanced a pair of borings with the CPT rig The first boring at each location, was used to record tip resistance, sleeve fnction and pore water pressure at five- centimeter intervals These data were processed and interpreted in the field Based on the interpreted sod and groundwater parameters, the second soil boring at each location was advanced ' to specific depths for discrete groundwater sample collection From CPT-1 B, a single groundwater sample was collected from a depth of approximately 149 feet ' From the other five CPT locations, three or four depth-discrete groundwater samples were collected from each boring at depths ranging from approximately 45 to 161 feet bgs All of the groundwater ' samples were collected with a Hydropunch® After deployment of the Hydropunch at each sample depth, it was checked for leakage, prior to exposing the four-foot long sampling screen All groundwater samples were collected with a decontaminated stainless steel bailer and into laboratory-supplied containers The containers were transported in an iced cooler with chain-of- custody documentation to Kiff Analytical, LLC (Kiff), a state of California certified hazardous waste testing laboratory (Certification #2236) Kiff analyzed each groundwater sample for TPH-as- gasoline, benzene, toluene, ethylbenzene, xylenes (BTEX), MTBE, di-isopropyl ether (DIPE), ethyl tertiary butyl ether(ETBE), tertiary amyl methyl ether (TAME), tertiary butanol (TBA), 1,2-DCA and 1,2-dibromoethane (EDB) by EPA Method 82608 Given that the extent of impacted soil has been defined, no additional soil samples were collected for laboratory analysis Immediately following the drilling of each soil boring, they were sealed with bentonite grout, placed to the bottoms of the boreholes with a tremae pipe or grout collar ' 23 Installation of Groundwater Monitoring Well Cluster on March 19, 2002, Mitchell Drilling Environmental (MDE), a state of California licensed drilling contractor(C-67#672617) installed a cluster of two groundwater monitoring wells north of the existing monitoring well network, to establish a groundwater monitoring capability downgradient of ' the known plume of impacted groundwater (Figure 2) The shallow monitoring well (MW-8A) was constructed as a groundwater table well, and the deep monitoring well (MW-8B) was constructed similar to MW-4 and MW-5, with screen intervals below the groundwater table MDE installed both wells in 8-inch diameter sod borings drilled with a CME-75 hollow-stem auger ng