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T .. � <br /> ze. <br /> ME <br /> Em <br /> Sim <br /> Grantline and East Roads Page 5 of 8 <br /> SUM-MARY OF FINDINGS <br /> 1. In general, a dark brown, stiff, dry clay underlies the tank <br /> area to a depth of approximately 2 feet. This strata is <br /> underlain by approximately 6 feet of damp, plastic, gray to <br /> olive-brown clay; immediately below this strata lies a <br /> saturated, gray, sandier, silty clay that contains the shallow <br /> water table. <br /> 2. Groundwater was encountered at a depth of 7.75 feet to 8'.8 <br /> feet below surface grade in a sandier silty clay. This layer <br /> is assumed to be the top of the shallow water table. <br /> 3. Petroleum hydrocarbons as gasoline were detected in the native <br /> soils adjacent to the UST's. This contamination was <br /> observed as odors, staining and analytically tested positive <br /> for TPH (as gasoline) using EPA Method 5030/6050. <br /> 4. Petroleum hydrocarbons as diesel were detected in the soil <br /> sample taken from the west portion of the tank field near the <br /> diesel UST and r.lso':iti the soil sample, B6-1, near the waste <br /> oil tank. Thele analytical results indicate concentrations <br /> above Correr"tive Action .Levels (CAL) established by the Water <br /> Quality Control Board and the regional Department of Health <br /> Services. <br /> 5. Oil and Grease was also detected in the soil sample taken from <br /> the wru)te oil UST and indicates concentrations of Oil and <br /> Grease above the CAL. <br /> 6. BTEX was detected in all 6 soil samples and is also above the <br /> CAL for BTEX. <br /> CONCLUSIONS <br /> 1. Based on the geological field data and analytical results it <br /> appears that the vadcse zone (saturated zone) has been <br /> impacted by hydrocarbon contamination near the USTs. <br /> 2. This hydrocarbon 0..catamiratior_ may be due to overspillage in <br /> the UST area, a common occurence at gasoline service stations. <br /> Another possible cause could be product loss due to a leaking <br /> tank or product line. <br /> 3. The extent of the contamination outward from the tank area is <br /> unknown at the present time. Additional shallow borings will <br /> be necessary_to_ further define__thevertical--and-hor-izontal <br /> -- — -- --- <br /> ertent of the contamination. <br /> 4. Further sampling of the groundwater and a detailed groundwater <br />