Laserfiche WebLink
August b, 1991 <br /> ARCO Station No. 548 <br /> p� <br /> are shown on plate 2 and were selected us+ng ARCO's guidelines for preliminary Tank <br /> Replacement As:=.essments. <br /> -. les collected from the boa s reported concentrations of total <br /> Analytical results of sot!same ng( arts per million (ppm), and <br /> gas 'CPHg) to 1,400 p <br /> petroleum hydrocarbons as g me� BTEX) <br /> concentrations <br /> of benzene, toluene, ethyibenzene, and tots! xylene isoTPH and <br /> compounds to 160 ppm in the soil samples collected from borings B-1 and B- . <br /> BTEX concentrat <br /> ions were below 1.0 ppm in soil samples collected from borings B-2,13-4.had <br /> and R,` ,except in the same <br /> le collected from 10 feet below grade in boring B which <br /> TPl-I concentration of 1.6 ppm. Table 2 presents the analytical results of soil samples <br /> a g , <br /> collected from the borings. <br /> plastic,and left at the site. <br /> Cuttings generated during drilling were Placed on and coveted collected from the drill cuttings, <br /> After analytical <br /> results were obtained on sail sample <br /> vatin and Hauling of Elk Grove, California, hauled the drill cuttings to <br /> Aronson Exca g <br /> Sacramento City Landfill in Sacramento, California. <br /> REGIONAL AND LOCAL GEOLOGY <br /> used of alluvial sediments <br /> The site is underlain by the Modesto Formation, han Allwais pdt, 1977)• The Modesto <br /> that range in size from silt to gravel (Marchand, etal. <br /> Formation dips gently to the west (Wagner, et al., 1981). <br /> pastern San Joaquin County Ground-Water Basin (California Department <br /> The site is in theJoaquin Public Health <br /> f Water Resources, 1988). According to personnel of the San <br /> o p round water <br /> Services, the regional ground-water gradient is to the southwest and depth to g <br /> S ? <br /> 4 <br /> d <br /> AGS 30004 <br /> t� <br />