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' Project No 034-97252 Page No 4 advanced to a total depth of 20 feet Boring BI encountered fill materials extending to a depth on the order of four teet, this boring may have been located on the margin of the former UST pit ' Based on the results of the January 14, 1998 drilling and sampling activities, four additional borings (P1, P2, P3, and P4) were advanced on the site on February 2, 1998 The additional borings were advanced to depths ranging from 20 to 40 feet using direct push (Geoprobe) equipment The locations of these borings are shown on Figure 2 Relatively undisturbed soil samples were obtained from each of the drilled and direct push borings at five-foot depth intervals and were field-screened for olfactory and visual evidence of petroleum ' hydrocarbons as well as screened with a photo ionization detector (PID) Soil samples were collected by driving a lined sampler into the soil The ends of each sample tube were covered with Teflon film and ' plastic end caps, and placed in a cooled ice chest for transport under cham-of-custody protocol to a State- approved laboratory in California ' On completion, all borings were backfilled Due to the limited depth of Bla, this boring was backfilled with cuttings Boring BI was backfilled with bentonite chips (placed in approximate one-foot Ilifts and hydrated) Borings P1 through P4 were backfilled with neat cement The pavement surfaces were patched at each boring location. Soil cuttings from Boring Bl were placed in labeled 55-gallon drum The drum is stored on-site until proper disposal can be arranged No cuttings were generated from the direct push borings All drilling and sampling equipment was decontaminated prior to use m order to minimize the possibility of cross-contamination I I 8.0 SOUL PROFILE The exploratory borings revealed generally uniform subsurface conditions characterized by clayey fill materials underlain by fine-grained, variably-cemented, cohesive native deposits Boring Logs are I presented in Appendix B Each boring encountered an approximate eight-inch thick pavement section consisting of asphaltic concrete over aggregate base materials Below the pavement materials, the borings typically encountered Isoft to medium stiff fill materials consisting of dark brown-grey silty clay extending to depths ranging from two feet to four feet In Boring P2, the fill materials extended to a depth of approximately nine feet, this 61 boring appears to be within the former UST pit Below the fill materials, native, stiff to hard light-brown fine sandy clayey silts were encountered The silt deposits were variably cemented with depth and IKRAZAN&ASSOCIATES,INC Offices Serving the Western United States I3497252 REP