COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

Lodi Food and Liquor Job #20-0166 Page 3 FIELD OBSERVATIONS During the field investigation conducted by CTE, no odors or soil discolorations were noted in the soil cuttings in any of the borings, with the exception of B-6. A faint petroleum hydrocarbon odor was detected from just below the surface asphalt to approximately 1.0 feet. No discoloration of the soil was observed throughout this interval. In general, the soil profile onsite consists of a brown, yellowish brown to reddish brown, silty sand (SM) to the depths explored. Minor discontinuous sandy clay lenses interbed the sand occasionally. Detailed soil classifications and descriptions may be found on the soil boring logs in Appendix A. LABORATORY RESULTS A total of twelve soil samples were analyzed by Precision Environmental Laboratories for TPH-G (EPA method 8015) and BTEX (EPA method 8020) . The lab results show non-detectable levels of TPH-G and BTEX in all seven borings, with the exception of B-2. TPH-G was detected at 11 milligrams per kilograms (mg/kg) or parts per million (ppm) in this boring at 21 feet. All copies of the chemical analyses completed may be found in Appendix B. CONCLUSIONS CTE's limited subsurface investigation of Lodi Food and Liquor found no field indications of petroleum hydrocarbon contamination onsite, with the exception of a faint odor in B-6 from just below the asphalt to approximately one foot. However, laboratory results for both samples taken in B-6 (1 .0 to 1.5 and 2.5 to 3.0) show no detectable levels of TPH-G or BTEX. The only positive laboratory result for the site was in B-2 at 21 feet, with 11 ppm of TPH-G. BTEX, a more volatile constituant of gasoline, is more mobile and tends to migrate to greater depths than does TPH-G. Due to the sandy soils in the area, it is possible that the low levels of TPH-G found in B-2 is indicative of a release which may have increasing BTEX levels at depths greater than 21 feet. Based upon the field observations and the laboratory data, it is CTE's recommendation that another boring be completed in the near vicinity of B-2, and advanced to an approximate depth of 45 feet. Samples would be obtained at five-foot intervals, starting at 15 feet and would be analyzed for TPH-G and BTEX. The purpose of this boring would be to confirm the presence of TPH-G in the subsurface soils and to determine if BTEX has migrated to greater depths then originally explored.