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r s Confirmation Soil Sampling Report Quik Stop Market No. 121 Page 2 retrieval, the sampling tube was removed, and a 6-inch long piece was cut and the soil sample was then capped, labeled, logged on a chain-of-custody form and stored in a chilled ice chest containing water ice for preservation in the field and during transport to a state-certified laboratory. In addition, undisturbed soil samples were also collected for moisture content, porosity, and bulk density. Upon completion of sampling at each location, bore holes were sealed with Portland cement to the surface, allowed to settle, and topped-off with cold patch asphalt. Subsurface Soils The two borings were logged during the collection of the soil samples. The subsurface soil at the two locations consisted of a brown to yellow-brown poorly sorted sand, which extended from just below the pavement to a depth of approximately 14 to 14 .5 feet at each boring location. The sand was found to be moist, medium dense and consisted of 90 to 95 percent very fine to fine sand. At approximately 14 feet, stiff grey brown clay was encounter. No petroleum odor was detected at either boring location. As previously mentioned, static groundwater was measured at approximately 16.7 feet below the ground surface. Copies of the boring logs are attached in Appendix A. Laboratory Analysis The four soil samples were analyzed for petroleum compounds at Entech Analytical Labs, Inc. (Entech), a state-certified laboratory located in Santa Clara, California. The laboratory reportedly employed methods approved by the RWQCB and the EPA. All samples were analyzed for total petroleum hydrocarbons as gasoline(TPHg)using GC-MS and benzene,toluene,ethylbenzene and total xylenes (BTEX) and fuel oxygenates, using EPA Test Method 8260B. The soil samples collected for geotechnical analysis were placed on hold, pending laboratory results for petroleum compounds. Discussion The laboratory reported all four soil samples to free of detectable petroleum hydrocarbons (Table 1). Since no petroleum was detected at either location, no vapor migration modeling was performed. In addition, the soil samples collected for geotechnical analysis were not tested due to the lack of petroleum hydrocarbons in the two soil borings. A copy of the laboratory report is attached in Appendix B. Based on the laboratory results, the soil contamination detected in the vicinity of monitoring wells RW-1 and MW-4 in 2000 has been remediated to "non-detect" (ND) concentrations. Therefore, the subsurface soil at the two boring locations pose no threat to human health through the migration of soil vapors. CCI respectfully request the County to review and recommend the site for case closure.