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I Canepa Is Car Wash 248 E Park Street, Stockton, Ca4fomia January 14, 1994 ' Interim Status Report on Phase II Investigation Page: 5 The samples were analyzed or extracted within 14 days according to their EPA methods Water samples collected for analysis were analyzed by EPA method 602 for BTX&E compounds, method 5030/modified 8015 for gasoline range hydrocarbons, and method 3510 for diesel range hydrocarbons The minimum detection limits used for each analyte were 0 5 ug/kg for BTX&E, 0.5 mg/l for gasoline, and 0 05 mg/kg for diesel. Analyses were conducted by Geo-Momtor of Hesperia, California, a State certified laboratory 4.0 Soil Conditions This site, at 248 E Park Street, Stockton, California, is located in the northern end of California's Sari Joaquin Valley This area is inonotonous geologically, representing primarily, the alluvial flood and delta plains of the major rivers and tributaries of the region The region persisted as a lowland or I shallow marine embayment during the entue Cenozoic period The surface of the Valley is composed of unconsolidated Quaternary sediments The Soil Survey completed in 1988 by the U. S Department of Agriculture, Soil Conservation Service, generally classify the soil types as being Jacktone, Hollenbeck or Stockton types Generally, these soils are somewhat poorly to moderately well-drained, fine texture soils that are moderately deep lto deep, down to a cemented hardpan The hthologic units encountered in these bonngs were interbedded :norgaruc mucaceous clayey silts and silty clays with numerous sands and silty, clayey sands of varying thicknesses Thus is typical of the valley fill deposits in the region tAnalysis of soil samples show B-1, 2 &5 to have the highest levels of contanunation, while & 3 & 6 and MW-1 &2 had significantly lower levels Boring B-3 and MW-3 are approching the lateral hrruts of contamination B-4 was the only boring that analyzed non-detect for all tested compounds and is at I the west edge of the plume (Table 1) I5.0 Groundwater Conditions California and Federal Governments have mandated that virtually all groundwater is beneficial for current or future use, unless it can be demonstrated that no beneficial use is known This aquifer is considered to be of beneficial use and as a result, must be protected from I contamination Those identified uses include agriculture and industrial, as well as potential use for animal or human consumption. The present water table was encountered between 50 and 52 feet below ground level un the borings Water level data during well development and sampling show the depth to water between 46 and 48 feet below ground level (Table 4) The analyses from the December 14, 1993 sampling event show BTEX and Gasoline contamination in MW-1, 2 and 3 (Table.), Appendix B)