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Revised Site Investigation Report & Case Closure Request Country Market C 10476 West Lfnne Road, Tracy, California a n to a g ro u p Antea Group Project No. CTRYMKTUST 2.3.2 Groundwater Sampling A groundwater sample was collected from the on-site domestic water well located approximately 100-feet east of the former USTs. Field personnel collected the sample from an access port located on the pump manifold, priorto the filtration system and pressure tank. The access port was purged by running the pump for 30 minutes prior to sample collection. The groundwater sample was collected in three 40 milliliter (mL) VOAs and placed in an ice- cooled chest following chain-of-custody procedures and submitted to Alpha Analytical, Inc. for the following analyses: • TPH-P (GRO) using EPA Test Method 801SB/8260B; • BTEX, MTBE, and 1,2-DCA by EPA Test Method 8260B. �T 2.3.3 Investigation Derived Waste Penecore placed soil cuttings generated during investigation activities into a Department of Transportation (DOT) approved 55-gallon drum, ,sealed, and labelled it in accordance with DOT protocols for non-hazardous waste, Antea Group temporarily stored the drum on-site, until it was picked up by Belshire Environmental Services, Inc. for transportation and disposal at an appropriate facility. Waste manifest is provided as (Appendix C). 2.4 Results 2.4.1 Subsurface Observations In SB-1, a silty gravel fill with sand was observed to approximately 5-feet bgs. Soil from 5- to 9-feet bgs was not recovered due to gravel blocking soil from entering the sample sleeve. At 9-feet bgs the lithology consisted of poorly graded fine to very fine sand with some small gravel, which extended to 18-feet bgs, where a well graded sand with some small gravel and silt was observed to the end of the boring at 20-feet bgs. In 513-2, field personnel observed loose silt with sand to approximately 8-feet bgs, with some small well-graded gravel in the bottom foot. From 8-feet bgs to the end of boring at 10-feet bgs medium dense silt was observed . Boring logs for both SB-1 and SB-2 are provided as Appendix D. The on-site domestic well is sealed at the top by a pumping mechanism and was unable to be gauged without damaging the pump. The Department of Water Resources (DWR) Water Well Drillers Report records the well screen between 162-feet bgs and 182-feet bgs with standing groundwater at 78-feet bgs after development in 1974. This is consistent with depth to water measured in an irrigation well across West Linne Road (87 feet bgs) drilled to 198 feet bgs in 1951. The Water Well Drillers Report for the irrigation well indicates depth to water in the well borehole did not change during drilling. 2.4.2 Soil Analytical Results TPH-P (GRO), BTEX, MTBE, and 1,2-DCA were not reported above the analytical laboratory minimum reporting limits (MRLs)in soil samples collected from SB-1 and SB-2. Low levels of lead were detected in SB-1 and SB-2 . In SB-1, the lead concentrations were 11 mg/kg and 7.6 mg/kg at 10-feet and 20-feet bgs, respectively. SB-2 had lead 4 www.anteagroup.com