Laserfiche WebLink
(YVATC <br /> . A S S O C I A T E S I N C <br /> groundwater was first encountered Groundwater samples indicated the presence of petroleum <br /> hydrocarbons Results are summarized in ATC's Summary Report of Additional Subsurface <br /> Investigation, dated September 9, 1998 <br /> On February 18, 1999, a geologist from ATC Associates supervised the installation of three <br /> groundwater morutonng wells from 39 to 41 feet bgs Soil bonngs MW 1, MW2, and MW3 were <br /> completed as two-inch monitoring wells One soil sample from each boring was collected and <br /> after the groundwater monitonng wells were developed on groundwater sample was collected <br /> from each well Soil and groundwater samples contained detectable concentrations of petroleum <br /> hydrocarbons Results are summarized in ATC's Summary Report of Additional Subsurface <br /> Investigation, dated June 1, 1999 <br /> SAMPLING ACTIVITIES <br /> On September 12, 2000, ATC Associates personnel collected groundwater samples from <br /> monitoring wells MW 1 through MW3 The locations of the monitoring wells are shown on <br /> Figure 2 Prior to collection of groundwater samples, the depth to water, pH, electrical <br /> conductivity, and temperature were measured in the monitoring wells and recorded A muumum <br /> of three well casing volumes was purged from each well prior to sampling The wells were <br /> allowed to recover and samples were collected from each well using dedicated disposable bailers <br /> The groundwater samples collected from each well were submitted to State-certified Sequoia <br /> Analytical (FLAP Cert No 1624) for chemical analysis of total petroleum hydrocarbons as <br /> gasoline (TPHg) utilizing EPA method 8015 modified, and benzene, toluene, ethylbenzene, and <br /> xylenes (BTEX) utilizing EPA method 8020 Groundwater well purge and sample logs are <br /> contained in Attachment 1 <br /> ANALYTICAL RESULTS <br /> The groundwater sample collected from well MW 1 contained detectable concentrations of TPHg, <br /> ethyl benzene, and xylenes The TPHg concentration was 8,200 parts per billion (ppb) and the <br /> chromatogram pattern indicated a weathered gasoline result Ethyl benzene and xylenes <br /> concentrations were 409 and 44 7 ppb, respectively <br /> The groundwater sample collected from well MW2 contained detectable concentrations of TPHg <br /> and benzene of 200 and 2 04 ppb, respectively Toluene, ethyl benzene, and xylenes were also <br /> detected at very low concentrations, ranging from 0 550 to 1 88 ppb The chromatogram pattern <br /> for TPHg indicated a weathered gasoline result <br /> The groundwater collected from well MW3 contained TPHg at a concentration of 2,060 ppb and <br /> the chromatogram pattern indicated a weathered gasoline result Benzene, ethyl benzene, and <br /> xylenes were detected at concentrations of 141, 34 7, and 12 6 ppb, respectively <br /> w 0498 Vquar l}r3g 2000 doe 2 <br />