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20 November 1995 <br /> AGE NC Project.No. 95-01'25 , <br /> Page 2 of 5 <br /> 2.3.. ' MONITORING WELL INSTALL•ATION.AND SAMPLING <br /> Between 1987 and 1992 a total'of tenround water monitoring' wells were installed at the site b <br /> g g y <br /> Groundwater Technology, Inc.'(GTI). No petroleum hydrocarbons were detected in soil samples <br /> collected during installation of the wells' <br /> Ground water was sampled on eight occasions between 1987 and 1995. Field observation of selected <br /> monitoring wells were.performed on an infrequent basis between 1993,and 1994 by representatives <br /> of LSD. <br /> Petroleum hydrocarbons were detected:.in ground water only in the vicinity of the former dispensers. <br /> Previous sampling events have established an ellipse=shaped ground waterplume, extending from <br /> MW-2 at the south to near MW-!5 at the north...The center-of the plume has apparently remained near <br /> MW-6 (GTI report dated3 March.1992). <br /> 2.4. GEOPROBE PENETRATIONS <br /> On 26 June 1995"five soil probings were advanced to'depths of ten-feet, using AGE's van-mounted <br /> Geoprobe 5400 soil probing'machine.: The location of the probing points is illustrated in Figure 2. <br /> Discrete soil,samples'were collected .at depths of five, seven and ten feet using a piston-type <br /> Geoprobe soil sampling assembly. . A'total of six soil samples were-analyzed for total petroleum <br /> hydrocarbons quantified as gasoline (TPH=g), total petroleum hydrocarbons quantified as diesel . <br /> (TPH-d) and volatile.aromatics (benzene; toluene; ethyl benzene and total xylene: BTE&X) in <br /> accordance with EPA methods 5030/8015m and 80201602, respectively. <br /> TPH-g was .detected in soil sample from probing P3 c llected'at a-depth of seven feet (P3-7) at.a <br /> concentration of 3,200 ppm. The same sample was found to contain TPH-d at 1,200 ppm. Toluene, <br /> ethyl benzene and xylene were detected also in this sample'at concentrations.of 9.2, 30 and 120 ppm; <br /> respectively. Petroleum hydrocarbons were not detected in other soil samples analyzed: <br /> Hydrocarbon-impacted soil was encountered near the southwest corner of the farmer gasoline UST <br /> excavation. However, the contamination does not app ar to be laterally or.vertically extensive. In'. <br /> -the June 1995 Quarterly Report, AGE recommend re-excavation of the impacted soil followed by on- <br /> site treatment or off-site recycling/disposal. <br /> 2.5. GROUND WATER DEPTH.AND FLOW DIRECTION <br /> Based upon data obtained:from monitoring wells at the site during the third-quarter'of 1995, ground <br /> -,water depth is approximately 8 feet below surface grade(bsg). Ground water flow direction at the <br />