COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

s 12 December 1995 AGE-NC Project No. 95-0140 Page 4 of 5 4.0. FINDINGS 4.1. SOIL LOGGING Silty sand was encountered in each probing to a depth of six feet bsg, while a fine-to medium-grained sand was encountered from a depth of six to twelve feet bsg. Moisture increased with depth in each boring. Organic vapors were not detected in any of the soil samples using a photo-ionization detector. Ground water was encountered during probing at a depth of approximately 12 feet bsg. Borings logs are included in Appendix A. 4.2. ANALYTICAL RESULTS OF SOIL SAMPLES A total of ten soil samples were submitted to the laboratory for analysis. Toluene was detected in eight of the ten samples analyzed at concentrations up to 0.13 mg/kg(parts per million: ppm). Xylene were detected in one soil sample (B-2 @10') at 0.008 ppm. No chlorinated pesticides or HVOCs were detected in any of the soil samples analyzed. Analytical results of the soil samples are summarized in Table 1. The laboratory report and chain-of-custody are included in Appendix B. 4.3. ANALYTICAL RESULTS OF GRAB GROUND WATER SAMPLES Toluene and xylene were detected in grab ground water samples from each probing at concentrations ranging from 1.5 µg/l (parts per billion: ppb)to 2.6 ppb. Benzene was detected in the sample from B-3 at 0.82 ppb. Chlorinated pesticides and HVOCs were not detected in the ground water samples. Laboratory results of ground water samples are summarized in Table 2. The laboratory report and chain-of-custody are included in Appendix B. 5.0. CONCLUSIONS AND RECOMMENDATIONS 5.1. HYDROCARBON-IMPACTED SOIL Trace concentrations of toluene and xylene were detected in soil samples from each probing. However, detected concentrations in the soil are below the State of California Maximum Contaminant Levels (MCLS) for toluene (150 ppb) and xylene (1,750 ppb) and are not likely to pose a threat to ground water.