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17 November 1999 AGE-NC Project No 95-0128 Page 3 of 7 3 The gradient determined for the three drowned wells was approximately 0 00125 fl/ft, the gradient for the four properly screened wells was approximately 0 0016 ft/ft If the elevation data for all wells are contoured, contorted lines of equal elevation are produced, suggesting that either frictional forces cause different elevation data between the properly screened and deeply screened wells, or that the flow regime in shallow ground water is somewhat independent of the deeper ground water encountered on the site The same effects on ground water elevation were found in the data for the 22 March 1999 ground water monitoring event, as shown on maps included in Appendix D The average ground water elevation on 27 October 1999 was approximately 2 03 feet lower than the average ground water elevation on 08 July 1999 On 27 October 1999 ground water in monitoring wells MW 1, MW2 and MW3 was approximately 27 92 feet, 21 10 feet and 20 55 feet over the tops of the wells' screened intervals, respectively The ground water table occurred within the screened intervals of the other wells monitored Ground water was inferred to be flowing approximately N 22°E in the properly screened wells (Figure 5) and N 42°E in the deeply screened wells (Figure 6) The gradient determined for the three drowned wells was approximately 0 0018 ft/ft, the gradient Ifor the four properly screened wells was approximately 0 002 ft/ft 3 2 ANALYTICAL RESULTS FROM GROUND WATER SAMPLES MAI received, extracted and analyzed the ground water samples on 13 July 1999 MAI issued a report dated 20 July 1999 The analytical results from the ground water samples are as follows • During the July 1999 ground water monitoring event, TPH-g, TPH-d, and various BTEX compounds were not detected in the ground water samples from the drowned wells MW I, MW2, and MW3 • Dissolved petroleum hydrocarbons were detected in samples from all the properly screened monitoring wells except the up-gradient monitoring well MW7 The highest concentrations I of hydrocarbons were detected in the water sample from monitoring well MWS, which contained 80,000,ug/l TPH-g, 9,000,ug/l TPH-d, 580,ug/l benzene, 9,400/Zg/l toluene, 4,100 µg/l ethylbenzene and 20,000µg/l total xylenes The lowest concentrations of hydrocarbons were detected in the sample from monitoring well MW6, which contained 410µg/1 TPH-g, II n /1 'rDL7 A A 1 /1 U n 9-7 /1 +-1 C '2 /1 +b-. 11 .,,. A 1? 11 +.+,1 /_.L W r,/1 L.L.11-U,-T i A4.gr 1 Ucnzcnc, V ! �. S/1 1V1U%Ilili, J J I4&1 %,Lily 1U V11Gli1 lli alill 1-7 Ak51 Mal xylenes E0 The concentrations of dissolved TPH-g decreased approximately half an order of magnitude in samples from MW6 and VW1, and increased more than an order of magnitude in the samples from MW4 and MW5 Advanced GeaEnvironmenial Inc I i I