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" `ol �! l.► 3.2 Soil Excavation and Backfilling (Phase II) As discussed below in Section 4, soil samples collected at depths of 17.5 to 20.5 feet from 6W borings CE-1, CE-2, and CE-4 did not contain detectable concentrations of VOCs. The soil sample collected at a depth of 4 feet from boring CE-3, drilled in the area of the former pipeline, was reported to contain acetone (0.140 mg/kg), benzene (0.017 mg/kg), and 2- `" butanone (0.025 mg/kg). Based on the U.S. Environmental Protection Agency's Preliminary Remediation Goals (PRGs) for residential sites (February 1, 1995), the concentrations of VOCs in the pipeline area soil were not likely to pose an unacceptable health risk.2 Nevertheless, based on discussions between Cypress and SJCPHS, Universal-Rundle Corporation elected to excavate the soil in the vicinity of boring CE-3 and dispose of if at Forward Landfill. This work was done in accordance with Cypress's August 23, 1995 Workplan for Soil Excavation and Additional Testing in Former Acetone Pipeline Area. V Figure 3 shows the approximate location of the pipeline area excavation. SEMCO excavated about 50 tons of soil in the area of boring CE-3 on September 7, 1995. The final excavation was approximately 11 feet by 10 feet by 8 feet deep. The excavated soil was placed directly into a truck and hauled to Forward Landfill, where it was stored in a temporary stockpile prior to disposal. During excavation, Cypress field screened the spoils for the presence of VOCs using a PID. VOCs were not detected above background concentrations. " After the excavation was complete, Cypress collected soil samples for chemical analysis from the base and four sidewalls of the excavation. The soil samples, which were collected in the presence of Mr. Steve Sasson, were obtained from the following depths. r • Bottom/base 8 feet bgs • North sidewall 5 feet bgs • East sidewall 4.75 feet bgs • South sidewall 5 feet bgs • West sidewall 4.5 feet bgs " Each soil sample was collected by driving a 2-inch-diameter by 6-inch-long stainless steel tube into the soil brought to the surface by the backhoe operator. The sample tubes were capped, `w labeled, sealed in plastic bags, placed in a cooler with blue ice, and taken under chain-of- custody to a State-accredited laboratory for analysis of VOCs, including acetone, by EPA Method 8240. Because VOCs were not detected in any of the samples collected from the base or sidewalIs of the excavation, SEMCO backfilled the excavation with clean, imported fill which was I.r 2 The reported concentrations of acetone, benzene, and 2-butanone were (i) 14,285, (ii) 82, and (iii) 348,000 times lower than their respective PRGs for residential sites. 6W CYPRESS Universal-Rundle Corporation Page 5 t�