Laserfiche WebLink
1 <br /> 11 June 1999 <br /> . AGE-NC Project No 97-0333 <br /> tPage 2 of 9 <br /> 2 2 UNDERGROUND STORAGE TANK REMOVAL <br /> In 04 December 1998, three gasoline USTs (UST Nos 1 through 3) and the associated <br /> dispensers/product piping were removed from a west section of the site (see Figure 2) Upon <br /> removal, soil samples were collected from the floor of the excavation and beneath product piping <br /> Total petroleum hydrocarbons quantified as gasoline (TPH-g) were detected beneath the east ends <br /> ' of the three USTs at concentrations ranging as high as 2,600 milligrams per kilogram (mg/kg), <br /> beneath the west ends of the USTs at concentrations ranging up to 25 mg/kg, and beneath product <br /> piping at concentrations ranging as high as 8,000 mg/kg <br /> ' Volatile aromaticsnzene toluene,e,ethylbenzene and xylenes BTEX} were detected beneath the <br /> east ends of three USTs at concentrations ranging up to 340 mg/kg, beneath the west ends of the <br /> ' USTs at concentrations ranging up to 2 7 mg/kg, and beneath product piping at concentrations <br /> ranging to 880 mg/kg <br /> ' Fuel oxygenates (methyl tertiary butyl ether MTBE, tert-amyl methyl ether TAME and tert- <br /> butanol TBA) were detected beneath the east ends of the three USTs at concentrations ranging up <br /> '. to 16 mg/kg, beneath the west ends of the USTs at concentrations ranging up to 3 1 mg/kg, and <br /> beneath product piping at concentrations ranging up to 690 mg/kg Analytiral results of sell sampler ! <br /> collected during tank removal activities are summarized in Table 1 <br /> 2 3 RL-'GICNAL GEOLOGIC SETTING <br /> ' The property is situated within n the Great Valley Geomorphic Province of California, a large, <br /> elongate, northwest trending, asymmetric structural trough The Great Valley Province has been <br /> ' <br /> filled with thick sequences of sediment ranging in age from Jurassic to Recent, creating a nearly flat_ <br /> lying alluvial plain extending from the Tehachapi Mountains in the south to the Klamath Mountains <br /> ' in the north The western and eastern boundaries of this province are comprised of the California <br /> Coast Range and the Sierra Nevada, respectively Rocks composing the basement complex of the <br /> province have not been completely defined but are believed to be metamorphic and igneous in <br /> origin The northern and southern portions of the Great Valley Province have been designated the <br /> Sacramento and San Joaquin Valleys respectively <br /> ' Based on the General Soil Map from the San Joaquin County Soil Survey published by the united <br /> States Department of Agriculture Soil Conservation Service in 1992,the site area is within the Delhi_ <br /> Veritas-Tinnin (DVT) association The DVT soils are located within dunes alluvial fans and strewn; <br /> ' terraces along the St.anislaus River, and generally consist of well drained coarse teNt>>red soils -1-1; <br /> ri <br /> soils are generally derived from both manne and non-mane sediment and are generally formed - <br /> allot auris denN ed from granitic and mixed rock sources <br /> 4dconced(.�uEnkironmE�ae, Ir=i � <br /> 1 <br />