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<br /> 17 December 1999
<br /> ;WAGE-NC Project No 96-0235
<br /> '!Page 7 of 11
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<br /> �I "The'permeability of sample B 11-35 was measured at 6 ,x 10 3 cm/sec The permeability of the
<br />' remaining 5 samples analyzed ranged from 3 x 10'to 3 x 10-$ Porosity ranged from 33 48 percent
<br /> to 43 47 percent Specific gravity ranged from 2 67 to 2 75 Percent organics ranged from 0 3 to 2 9
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<br /> `Results of physical analyses arE summarized on Table 31 The laboratory report is included in
<br /> Appendix B
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<br /> 3 3 'GROUND WATER GRADIENT'AND FLOW DIRECTION
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<br /> * The casing elevation of each well was previously,,surveyed relative to a City of Stockton bench mark
<br /> 1' The elevation of ground water in each well was calculated by subtracting the depth to ground water
<br /> from the surveyed casing elevations (Table 4) Depths to ground water ranged from 17 21 feet to,,f ;
<br /> 19 72 feet below,the tops of the well casings Ground water elevations at the site ranged from -1123:,
<br />' feet in MW-6A to -12 97 feet mean sea level (MSL) in MW-2 Ground water elevation increased;
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<br /> '3 04 feet in MW-6B, countering the decrease observed during the previous monitoring event, ground,
<br /> Ywater elevation decreased an average of 196 feet in the remaining wells
<br /> 1 To infer ground water flow direction, the ground water elevation data was divided into two sets `
<br /> + based on the well screen intervals Ground water was between 20 3 and 22 8 feet above the screened,
<br /> intervals in monitoring wells MW-1, MW-2, MW-6B, MW-8B and MW-9, comprising the deeper
<br /> water data set Ground water was within the screened intervals'for monitoring wells MW-4,MW-6A,
<br />' MW-7, MW-8AIand MW-10 and approximately 12 3 feet above the screened interval in MW-3,
<br /> comprising the shallow water data set Figure 3 illustrates the ground water elevations based on the
<br /> two data sets Ground water-flow direction was calculated to be southwest using data from wells
<br />' screened,within the lower interval Ground water elevations',,bakd upon data from the shallow'wells r
<br /> indicate an apparent mound near•MW-6A, but a generally northerly flow direction with the
<br />' remaining wells ;
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<br /> 3 4 ANALYTICAL RESULTS OF WATER SAMPLES
<br /> TPH-g'and TPH-d were detected in the grab water sample collected from B9 at concentrations of,
<br />' 240,000 parts per billion`(ppb, reported as micrograms per liter) and 270,000 ppb; 'respectively ;
<br /> BTEX cmpo
<br /> ounds were detected'in the grab water sample at concentrations of 540 ppb; 28,000 ppb,,,
<br /> 7;100 jppb and' 38,000 ,ppb, respectively :MTBE was detected by"EPA Method 8260 at a"
<br /> h concentration of 230 ppb
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<br /> 1 M f ' ' ' h
<br /> TPH-g and TPH-d were detected in the samples collected from MW=f,=MW-2, MW-9 and MW-f0
<br />' at concentrations as high as 20,000 ppb BTEX compounds were detected ink these wells at
<br /> ,concentrations as high as 2,000 ppb, 1,400 ppb,'840 ppb'and,,3,200 ppb; respectively Toluene and
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<br /> Advanced GeoEnvironmental,Inc
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