ARCHIVED REPORTS_XR0006746 CASE 1

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i groundwater sampling The first boring at CPT-1 was advanced to a total depth of 100 feet and the first boring at the other three locations were drilled to a total depth of 90 feet Pore pressure dissipation tests were recorded when suspected groundwater-bearing zones were encountered during drilling The CPT plots, pore pressure dissipation plots, and interpretation output are ' included in Gregg's report (Appendix B) A total of seven soil samples were collected with the CPT rig From CPT-1, one soil sample was collected at 40 feet bgs From CPT-2, soil samples were collected at 45 and 50 feet bgs From CPT-3 and CPT-4, soil samples were collected at 40 and 50 feet bgs All of the sod samples were collected into stainless steel sample sleeves with a push-driven sod sampler The samples were sealed with Teflon® film and plastic end caps, labeled, and transported in an iced cooler with jchain-of-custody documentation to Kiff Analytical, LLC (Kiff), a state of California certified ' hazardous waste testing laboratory (Certification #2236) Kiff analyzed all seven soil samples for TPH-as-gasoline, BTEX, MTBE, DIPE, ethyl tertiary butyl ether(ETBE), TAME, TBA, 1,2- dichloroethane (1,2-DCA) and 1,2-dibromoethane (EDB) by EPA Method 8260B Based on the CPT and pore pressure dissipation data, possible groundwater-bearing zones were identified beneath the groundwater table In CPT-2 and CPT-3, a groundwater zone was identified at approximately 57-58 feet bgs In CPT-4, a groundwater zone was identified at i� approximately 66 feet bgs In all four CPT locations, a deeper groundwater-bearing zone was also identified at approximately 77-78 feet Gregg discretely sampled each of these groundwater zones with a HydropunchTm To evaluate the possible presence of groundwater from overlying zones, the Hydropunch was deployed and checked for leakage, prior to exposing the sampling screen The samples were collected with a decontaminated stainless steel bailer into laboratory supplied bottles, labeled, packaged in an iced cooler, and transported with chain-of-custody documentation to Kiff for analysis Kiff analyzed all seven groundwater samples for TPH-as- gasoline, BTEX, MTBE, DIPE, ETBE, TAME, TBA, 1,2-DCA and EDB by EPA Method 82606 Following sampling, Gregg sealed the boreholes with cement grout, placed by the tremae method 2.3 Groundwater Monitoring Well Installation On September 18, 2000, Ramage Environmental supervised V&W Drilling, Inc (C-57 License #720904) install four on-site groundwater table monitoring wells to establish a groundwater monitoring capability at the site The locations of the four wells (MW-1, MW-2, MW-3, and MW-4) are shown on Figure 2 9