ARCHIVED REPORTS XR0012685 - Laserfiche WebLink

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Work Plan May 1.7, 1991 ARCO Service Station No. 2130, Stockton. California AGS 30003-1W indicating relative ieveis of gasoline hydrocarbon vapors but do not detect the concentratiu.. of gasoline hydrocarbons present with the same precision as laboratory analyses. Any subjective evidence of gasoline hydrocarbons such as soil discoloration or M obvious odor will be noted. The first boring will be drilled near the gasoline tank cavity approximately 2-1/2 feet from the edge of the existing tank area, near the fill ends of the product tanks, to 30 feet below grade, ground water, or auger refusal,whichever is encountered first. If the PID reading of the soil sample collected at'30 feet below grade is greater than 50 parts per million by volume (ppmv), we.will drill until: (1) two.consecutive samples collected.at 5- foot intervals produce PID readings of less than 50 ppmv,(2) until we encounter ground - water,or(3):auger refusal; ti ®If the first boring near the gasoline tank cavity is terminated above 30 feet below grade. three additional soil borin s will be drilled approxi ely 2-1/2 feet from the edge of the tank area, equally spaced around the tank perin f the first boring is drilled deeper than 30 feet, borings will be drilled around the existing tank cavity using the above criteria until two consecutive samples collected at 5-foot intervals produce PID readings of less than 50 ppmv. In this case, a boring will not be drilled on the end Opp osito from the fillport. If young_ d water is not encountered in the dee est bort the last boring drilled near the existing cavity will be drilled 20 feet beyond the depth oft e eAlIother borings or to ground water. This final boring will be drilled to evaluate the groundwater level or to log the soil 20 feet below the last evidence of hydrocarbons. This additional information on the subsurface will assist in any future remediation plans. S� (-3(D' , -,L-3 � > ° 7 Applied GeaSystW"S