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Mr Travis Bryant February 11, 2002 Page 2 Project No 2002-1426-01 have or previously had USTs Based on data collected from subsurface investigations performed at the former ARCO Service Station, the Chevron Station, The Transmission Shop, and the Texaco Service Station, residual and dissolved hydrocarbons have been detected beneath these facilities, and a commingled plume exists beneath Charter Way and Lincoln Street It is our understanding that the groundwater flow direction near the intersection has generally been toward the east-northeast and east-southeast The groundwater plume has not been delineated, but reportedly, extends down gradient as far as Van Buren Street A work plan to further evaluate the extent of hydrocarbon impact, dated January 28, 2000, was submitted to San Joaquin County Department of Public Health Services, Environmental Health Division (PHS/EHD) The scope of work included vertical assessment using Cone Penetrometer Testing (CPT) followed by discrete soil and groundwater sampling from two soil bonngs to a total depth of approximately 120 feet bgs Status retained Gregg Drilling and Testing, Inc , and the work was completed on May 30, 2000 Results of the investigation were presented in a findings report dated October 27, 2000 GROUNDWATER MONITORING On December 6, 2001, a Stratus representative measured depth to groundwater and collected . groundwater samples from the two onsite groundwater monitoring wells for subjective and laboratory analyses Floating product was not observed in any of the groundwater monitoring wells The locations of the monitoring wells are presented on Figure 2 Groundwater Elevation Fourth quarter 2001 groundwater levels were measured on December 6, 2001, using an electronic sounding device, and recorded on the field data sheets presented in Appendix A Table 1 presents the historical and fourth quarter 2001 groundwater elevation data At the time of the fourth quarter 2001 monitoring event, groundwater was encountered in MW-1 and MW-2 at depths of 21 50 and 21 69 feet bgs, respectively Groundwater elevations decreased approximateTylT97feet since the previous sampling event (August 16, 2001) Groundwater flow direction and gradient were not calculated, as data from only two monitoring wells is available Sampling, Analysis, and Monitoring Program Results Groundwater samples were collected from wells MW-1 and MW-2 on December 6, 2001 Appendix B presents the sampling procedures used Samples were forwarded for analysis with appropriate chain-of-custody documentation to Alpha Analytical Laboratory, a California state certified laboratory Groundwater samples were analyzed for TPHG using USEPA Method 8015B/DHS LLFT, and for benzene, toluene, ethylbenzene, and total xylenes (BTEX), methyl tertiary butyl ether (MTBE), tertiary amyl methyl ether (TAME), tertiary butyl alcohol (TBA), di-isopropyl ether • (DIPE), ethyl tertiary butyl ether (ETBE), and 1,2-di chloro ethane (1,2-DCA) using USEPA Method 8260B P 11 B C4Stockton\Qrt1y1200111BC Stockton-4Q01 doc 5TRAruS