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r 16 April 2000 AGE-NC Project No. 98-04681 _. Page 3 of 4 SA FINDINGS 'Ground water elevations were- .determined by subtracting the'mcdsured depths-to-water from 14C 'surveyed casing-elevations. Ground water•flow direction-was determined by.contouring the water ' elevations on a"sealed site plan (Figure 3). t WATER.-ELEVATION AND FLOW DIRECTION. 3.1. � GROUND During the March 2001 rnoriitoring event;•the depth to ground water at the site ranged from 9.46 to ed • 10:37 feet-Below the tops of well casings (btoc) (Table 1). Ground water elevation at the site ranged from 2.57 to 3.06 feet below mean sea level (MSL). Gro uridiwater'elevation in the monitoring wells „ increased an'ayerage of 0.9 feet since the previous monitoring event•(November 2000): A summary•.' of depth to ground water and ground water elevation measurelreerits is presented in"Table 1., ,. : A ground water elevation contour map-for'March'2001 is illustrated on Figure.'3 Based,on`ground r water elevation data, ground water flow direction is.inferred"to be toward the northeast. Ground ' water gradient for the latest sampling event was calculated to b&,0.012'. In general; ground water flow direction and gradient for this monitoring event appear to be consistent with previous rrlonitoring events results. 3.2. LABORATORY RESULTS.OF GROUND.WATER SAMPLES Ground water samples'were collected from MW-3 .through MW-8 for laboratory analysis. A sulnmary of ground water analytical results are,presented in Table 2.The laboratory analytical report.. ' is included in Appendix B. , Toluene*and xylene were reported in the sample collected from.well MW.-6 at-a concentration of 2.3 micrograms per liter (µg11) and 1.9 µgill, re.spectively.'There were'rio: other reported detections of BTEX compounds;TPH-d.or TPH-g'in the other ground water samples analyzed,during the March. ` 2060 monitoring event (Table 2)." MTBE was reported iii the ground water samples collected-from monitoring wells MW-4 and MW-6 at concentrations o£51 µg11 and 9Qµg1.1, respectively, by EPA Method 8020. MTBE.wa.'reported ' in the ground'water' samples.collected from,rnoni#oring wells MW-3,"1VI W-4 and MW-6 .at ' concentrations of 4.5 µg11; 51 µg11 and 89µg/l; respectively,-by EPA Method 8260... ; ' ,The MTBE'concentration in these samples exceed the DHS _ establi'shed maximum contaminant • A� ; level.(MCL)of 5 µg11 for MTBE'in ground water:The DHS action level for,MTBE'is 13 µg11: There were no.reported detections"of any other fuel-oxygenating compounds. 4dvanced GcoEnvironmental,Inc."