Laserfiche WebLink
'. 02 April 1998 <br /> AGE-NC Project No 95-0105 <br /> Page 2 of 3 <br /> sample preservative and into one 1-liter amber bottle After collection, the samples were properly <br /> labeled, placed in a chilled container and transported under chain-of-custody to McCampbell <br /> Analytical, Inc (MAI) Each sample was analyzed for <br /> • Total petroleum hydrocarbons quantified as gasoline and as diesel (TPH-g and TPH-d) by <br /> EPA Method 8015m, <br /> ' • Volatile aromatic compounds (benzene, toluene, ethylbenzene and total xylenes BTE&X) <br /> by EPA Method 8020, and <br /> • Methyl tertiary-butyl ether(MTBE),tertiary butyl alcohol(TBA),di-isopropyl ether(DIPE), <br /> ethyl tertiary butyl ether (ETBE) and tertiary amyl methyl ether(TAME)by EPA Method <br /> ' 8260 <br /> 3.0. FINDINGS <br /> 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> t• The elevation of ground water in each well was calculated by subtracting the ground water depth <br /> from the surveyed casing elevation(Table 1) The casing elevation of each well had been previously <br /> ' surveyed relative to a City of Tracy bench mark <br /> Ground water elevations at the site ranged from 23 61 to 23 32 feet Between August 1997 and <br /> ' January 1998, ground water elevation Increased an average of 1 3 feet at the site <br /> The ground water flow direction in January 1998 rotates from due north on the southern portion of <br /> ' the site to a northwest direction between wells MW-3 and MW-4 The flow direction remains <br /> northwest away from well MW-4 Figure 3 -Relative Ground Water Elevation Contour Map depicts <br /> the ground water elevation contours at the site <br /> 3 2 PETROLEUM HYDROCARBON-IMPACTED GROUND WATER <br /> ' w t and water samples collected from MW-5 and <br /> None of analytes of interest were detected in he ground p <br /> ' MW-6, all the analytes of interest were detected in the ground water sample collected from MW-4 <br /> TPH-g and TPH-d were detected in monitoring well MW-4 at concentratioris of 8,500 parts per <br /> billion (ppb, reported as micrograms per liter) and 1,400 ppb, respectively Benzene, toluene, <br /> ethylbenzene and xylenes were detected in monitoring well MW-4 at concentrations of 100 ppb, 590 <br /> ppb,470 ppb and 1,300 ppb,respectively by EPA Method 8020 Oxygenated volatile organics were <br /> not detected in any of the three samples by EPA Method 8260 <br /> Advanced GeoEnwronmentai,Inc <br />