ARCHIVED REPORTS XR0010233 - Laserfiche WebLink

Home Browse Search

Former Discovery Chevrolet June 6, 1997 Tracy,California Re ort of Additional Subsurface Investigation site. Five wells, both public and private were identified within this radius (Figure 4, Table 4). The nearest well in the approximnate downgradient direction, 41, is 700 feet north- northeast of the site and according to DWR records is 427 feet bsg completed in deeper strata. The closest well found in the records is 650 feet southeast (upgradient) from the site. It does not appear that gasoline hydrocarbons beneath this site will be a threat to any of the wells that were found during this record review. LABORATORY METHODS AND RESULTS Soil Samples Characterization samples were collected and analyzed from selected hand borings at 8 feet bsg (S-0403-A through 1-8) and at 5 and 8 feet bsg from SK (S-0403-K5 and S-0403-K8), and selected soil samples collected from the borings for MW-4 (S-6.5-MW4) and MW-5 (S- 5-MW5) at 61/2 and 5 feet, respectively. The selected soil samples along with the samples collected from the stockpiled cuttings (SP-0404 A,B,C,D), were submitted under Chain of Custody (COC) to Excelchem Environmental Labs (Excelchem) in Roseville, California (Certification No. 1760, 2119). No samples from hand boring location SJ were analyzed. The samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg) and for the gasoline constituents benzene, toluene, ethylbenzene, xylene (BTEX) using EPA methods 30501801518020. The highest hydrocarbon analyses results were noted in hand borings SB and SK in the vicinity of the former product lines (Figure 3). The TPHg/Benzene results in boring SB at 8 feet bsg were 4,370116.5 ppm. Boring SK was analyzed at 5 feet (6,110115.7 ppm) and 8 feet(6,290/18.5 ppm) bsg. Laboratory soil analyses results are summarized in Table 1. Laboratory analytical reports and COC forms are included in Appendix F. 3041-11.rpt 6 HORIZON ENVIRONMENTAL INC.