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i Folsom Full documentation of the excavation activities is presented in the Preliminary Investigation and Evaluation Report (PIER), dated April 5, 1993, prepared by GeoAudit During both phases of excavation, a total of 15 samples were collected from the sidewalls and floor of,the excavation All samples were collected at the direction of Ms Mary Meays } of the PHS/EHD As the excavation proceeded, the soil was screened for the presence of organic vapors using a photo -ionization detector (PID Thermo Environmental 580A, 10 0 - • -> eV, calibrated to isobutylene) and segregated into contaminated and clean stockpiles 7 Analytical results of soil samples collected during excavation activities are presented in Table - 5 2.7.1 Phase I Excavation, August 30 - 31, 1993 Soil was excavated to a depth of 30 feet, removing approximately 1,000 cubic yards of soil from the former UST site Most of the soil samples collected were uncontaminated, however, one sample from the floor (sample B1-32) and two samples from the west wall (samples W-26 and W-29) contained trace concentrations of petroleum hydrocarbons (Table 3) 2.7.2 Phase II Excavation, September 21, 1993 During the second phase, the excavation was deepened to a total depth of 39 feet No petroleum hydrocarbons were detected in soil samples collected from the west wall of the excavation during this phase Only sample 135-39, collected from the floor of the excavation at a depth of 39 feet, had any detectable hydrocarbons Benzene and toluene were detected at 0 006 ppm and 0 007 ppm, respectively The detected levels of benzene and toluene are slightly above the 0 005 ppm detection limits for these compounds 2.7.3 Collection of Soil Samples from Clean Stockpiled Soil, October 1993 MU Soil from the "clean" soil piles was sampled on October 6, 1993 Eight samples were collected from the stockpiled soil under the direction of Ms Meays The samples were composited by the laboratory into four samples No contamination was detected in the any of the samples collected from the "clean" soil piles 2.7.4, Collection and Disposal of Contaminated Stockpiled Soil, October 1993 It is our understanding that on October 22, 1993, twenty samples were collected from the "contaminated" soil pale by Ned Pepper, Inc (NPI) Samples were obtained by hand augering to a depth o€1 5 feet, and then using a hand -driven metric soil sampler Samples were collected in clean 2 x 6-mch brass sleeves Immediately following collection, the samples were labeled, placed in a chilled container, and transported under chain -of -custody by NPI to Sparger Technology, Inc, a state -certified laboratory Oea6�cal Anda 3.e.K-ti [ae, r 161I44UM.dCy] qA a