FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

rN r 05 December 1995 AGE-NC Project No. 95-0178 Page 2 of 4 x r Section(1993),the depth to ground water in the vicinity of the site is approximately 7n and 80 feet below surface grade(bsg). . 3.0. SITE ASSESSMENT AND REMEDIATIO 3.1: 'EXCAVATION OF HYDROCARBON-Ilv1PA TED SOIL On 22 October 1992, additional hydrocarbon-impacted s iI was excavated from the.diesel UST area to a depth.of 17 feet bsg by FEA A total of five soil camp es were collected from the walls and floor of the excavation. However, because organic vapors w re detected in excavated soil, the samples were not submitted to a laboratory for analysis. Orgai Lic vapors were monitored using a photo- ionization detector (PID) precalibrated to isobutylene; the maximum OV concentration detected in the field was 1807 ppm. Excavated soil was stockpiled on-site on plastic sheeting (Figure 2). 3.2. 'SOIL DRII.LING AND SAMPLING-NOVE ER 1994 On 28 November 1994, two soil.borings (B 1 and 132) vere advanced near the former diesel UST excavation to evaluate the extent of hydrocarbon impact (Figure 2): The borings were advanced utilizing a truck mounted drill rig equipped with continuou 5 flight 8-inch diameter hollow stem augers . to a maximum.depth of 40 feet below site grade (bsg). Drilling and sampling was supervised by a representative of Geological Audit Services, Inc. (GAS . In each boring, soil samples were collected at five-foot intervals using a split-tube sampler loaded with three pre-cleaned brass sleeves. The samples we a preserved in a container under ice and r -transported to McCampbell Analytical, Inc. (MAI) for analysis of TPH-g, TPH-d and volatile aromatics(BTE&X), in accordance with EPA methods 8015, 8015 modified, and 8020, respectively. - A total of.six soil samples were analyzed from B 1 and B2, , o petroleum hydrocarbons were detected . in any of the samples analyzed. Analytical results of the soil samples are summarized in Table 2. The laboratory report and chain-of-custody form are included in Appendix A. U .� 3.3. BACKFILLING OF EXCAVATION In July 1995, the "UST excavation was backfilled to surface grade with clean .fill material. The excavation was backfilled by representatives of CWI.