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Mr Kyle Christie September 23, 1996 • Page 3 Local Geology and Hydrogeology. Site lithology was classified using the Unified Soil Classification System (USCS) Soil samples for lithologic classification were collected every 5 feet The vadose zone (approximately 16 feet thick) consists of interbedded silty sands Thin layers of moderately dense silty clays were encountered at 0 5 to 1 foot bgs and at 14 5-I6 feet bgs Underlying the lower silty clay zone was a saturated clayey silty sand The borehole was terminated in this clayey silty sand The lithologic log of the MW-1 is attached as Appendix E Groundwater was first encountered during drilling at the contact of the lower silty clay zone and the clayey silty sand (approximately 16 feet bgs) After completion of the well, static groundwater was measured at approximately 10 5 feet bgs The lower silty clay zone appears to be a semi-confining hydrologic unit based on the rise in groundwater from the depth at which it was first encountered during drilling Soil Sampling Analytical Results. Soil samples were submitted to Sequoia Analytical (Sequoia) in Sacramento, California Sequoia is certified by the State of California Department of Toxic Substance Control for the analysis of hazardous materials (California State Certificate Number 1624) Three soil samples collected from MW-1 (5-5 5, 10-10 5, and 15-15 5 feet bgs) were submitted to the laboratory for analysis of total petroleum hydrocarbons as gasoline (TPH-G), benzene, toluene, ethylbenzene, and xylenes (BTEX), and methyl tertiary butyl ether (MTBE)by the Environmental Protection Agency(EPA) Method 503018015/8020 Stockpiled soil was sampled and analyzed for TPH-G, BTEX by EPA Method 8020/8015 Modified, and STLC for lead by EPA Method 6010/7000 series The stockpile soil analyses were performed for waste characterization purposes BTEX, TPH-G, and MTBE concentrations were below or slightly above respective analytical reporting limits(ARLs)in all soil samples Table 1 summarizes the analytical soil results Groundwater Sampling Results. The groundwater sample was submitted to Sequoia for analysis MW-1 groundwater sample was analyzed for TPH-G, BTEX, and MTBE using EPA Method 5030/8015 and 8015 Modified Toluene, ethylbenzene, xylenes, and TPH-G concentrations were below ARLs Benzene was identified in MW-1 at a concentration of 0 54 micrograms per liter (µg/L) MTBE was identified in MW-1 at 35 micrograms per liter (µg/L) Table 2 summarizes the analytical groundwater results Use or disclosure of data continued on this sheet is subject to the restriction specified at the beginning of this document 401 RREPORM5450RPT1 DOG