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1 <br /> Department Site Mitigation Unit (SJCEHD) by Avalon on May 18, 2000 (Appendix <br /> VI and VII) Prior to conducting subsurface exploration and soil sampling, <br /> 1 Underground Service Alert was contacted in order to clear the boring locations <br /> from underground utilities Four geoprobe borings were drilled on the subject <br /> property and six were drill offsite and to the northeast of the subject property All <br /> borings were advanced to depths of 20 feet bgs All of the borings were <br /> continuous cores with plastic liners Groundwater samples were collected from all <br /> 1 nine of the ten borings No groundwater sample was collected from GP-2 because <br /> the casing was met with refusal due to pea gravel caving GP-2 was located within <br /> four feet of an existing well MW-1 therefore the groundwater conditions were <br /> known in this particular area All groundwater samples were analyzed for <br /> oxygenate compounds and lead scavengers Methanol, Ethanol, Tertiary Butanol, <br /> Methyl Tertiary Butyl Ether (MTBE ), Di-isopropyl Ether (DIPS), Ethyl Tertiary Butyl <br /> Ether (ETBE), Tertiary Amyl Methyl Ether (TAME), 1,2 Dichloroethane and 1, 2 <br /> Dibromoethane by EPA Method 8260, TPH by EPA Modified Method 8015 as <br /> Diesel and Gasoline Select Soils samples collected were analyzed for oxygenate <br /> compounds, TPH as Gasoline, permeability and organic carbon <br /> 1 <br /> All groundwater samples were collected using Teflon tubing and transferred to <br /> appropriate containers supplied by the analytical laboratory Samples were placed <br /> on ice in a portable cooler for transport under chain of custody to Kiff Analytical <br /> . Laboratory <br /> 1 <br /> 3.0 GENERAL SITE INFORMATION <br /> 3.1 Site Location <br /> I The subject property is located on the east side of Harlan Road, east of the Golden <br /> State Freeway in Lathrop California The subject property contains a two-story <br /> structure with a mini market on the ground floor, and an office on the second floor <br /> Surrounding the mini market are gasoline and diesel dispensers <br /> 3.2 Geology and Hydrology <br /> Geology-The subject property is in the northern portion of the San Joaquin Valley <br /> Basin, a structural basin within the northern part of the Great Valley Geomorphic <br /> Provence of California Unconsolidated alluvial sediments of Quaternary age <br /> 1 underlie the site Soils encountered in the borings consist of fine grained <br /> sediments such as fine sands, silts and clays The continuous coring performed as <br /> part of this investigation revealed an extremely coarse grained sand from <br /> approximately 12 to 20 feet bgs Permeability and porosity analysis performed as <br /> part of this investigation show moderate to high permeability and porosity <br /> • Avalon Environmental Consultants <br /> 9627-001 6 <br /> foes Truth Plaza <br /> DD S <br /> April 15,2001 3 156Harlan Road <br /> Lathrop California <br />