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_ _ ¢ r <br /> r _ <br /> ItiTER?In:ICi\nL- CHNOI.�^-G'f C0i?Fpi2�;':Cti <br /> EXECUTIVE SUMWy <br /> IT Corporation (IT) was retained by SP Oil Company to perform a site <br /> assessment as described in the IT Corporation PRELIMINARY HYDROGEOLOGIC <br /> ASSESSMENT. <br /> The investigation included the installation and sampling of four thirty-foot <br /> monitoring wells. During drilling soil samples from each borehole were <br /> collected at five-foot intervals with three samples collected above the water <br /> table interface (i.e., samples from a twenty-foot depth) submitted for <br /> chemical analysis. Following well installation, all well casings were <br /> surveyed to a common datum. Survey data combined with wa'e* level measure- <br /> ments in each well were utilized to calculate the directional flow of shallow <br /> groundwater. <br /> ter. <br /> Soils encountered at each borehole consisted primarily of a lean clsy below <br /> w, approximately two to three feet of well-graded gravel fill. At an approximate <br /> depth interval of twenty-two to twenty-six feet below grade, a clayey sand <br /> layer comprised the primary water bearing unit encountered. <br /> �1 Water level measurements indicate that the groundwater flaw direction is <br /> r_ north-northeast under a gradient of 0.004 ft/ft. As such, MW-3 is located <br /> , f <br /> airectly downgradient of the gasoline tank field and pump islands, while MW-1 <br /> �. <br /> and MW-4 are located side gradient and MW-2 is Inca <br /> ted upgradient of the on- <br /> site petroleum hydrocarbon storage and transfer facilities. MW-4 is also <br /> located adjacent to a waste olf and motor oil tank field. <br /> No free product was observed in any of the monitoring wells. Total petroleum <br /> hydrocarbons as gasoline were reported in water samples from MW-1 and MW-3 at <br /> — concentration of 0.140 <br /> PPM and 0.20 ppm respectively. Mon-detectable levels ' <br /> of TPH as gasoline were reported for all soil samples analyzed. <br /> NO fecal coliform was detected in groundwater samples from MW-1, HW-2 and <br /> HW-3. <br /> The remove] of the gasoline tanks and piping is in the planning process. <br /> Results from this work will help determine if further investigation is <br /> warranted. <br /> %:ENG:7024/07239a <br />