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�ssM � <br /> . Working To Restore Nature <br /> Groundwater samples were collected from monitoring wells MW 1, MW2, MW3, MW5 and <br /> MW6 on March 9, 1994 after stabilization of pH, electrical conductivity (EC) and <br /> temperature The monitoring wells were purged using an above-ground centrifugal pump <br /> with dedicated tubing Well purge logs are included in Attachment A Samples were <br /> analyzed for benzene, toluene, ethylbenzene, and xylenes (BTEX) and total petroleum <br /> hydrocarbons as gasoline (TPHg) by EPA methods 8020 and modified 8015, respectively. <br /> ANALYTICAL RESULTS <br /> No dissolved gasoline hydrocarbon constituents were reported at or above detection limits to <br /> monitoring wells MW 1, MW2, MW3, MW5 or MW6 Laboratory data are summarized in <br /> Table 2 <br /> Influent and effluent samples from the pumping well (MW4) were collected for analysis of <br /> BTEX and TPHg on March 9, 1994 Analytical results indicate a general decrease in TPHg <br /> and BTEX concentrations in the influent sample (INF) collected during this sampling round <br /> The sample collected from carbon filter 1 (EFF1C) did not contain any detectable analytes <br /> TPHg and xylenes were reported 1n the sample collected from carbon filter 2 (EFF2Q, <br /> however, laboratory personnel indicated that this was possibly due to instrument <br /> contamination from a previous sample Influent BTEX and TPHg concentrations over time <br /> are plotted on Figures 5 and 6 <br /> Laboratory analyses were performed by Sequoia Analytical Laboratory (ELAP No 1210) <br /> The analytical results are summanzed In Table 2, the laboratory reports and chain of custody <br /> documentation are presented in Attachment B <br /> REMEDIATION SYSTEM PERFORMANCE <br /> No down time was reported for the remediation system during the first quarter of 1994 The <br /> system operated at an average rate of approximately 2 liters per minute It is anticipated that <br /> a flow meter will be installed during the second quarter of 1994 <br /> Overall, analytical results support the effectiveness of the system Histoncal sampling results <br /> show fluctuating influent hydrocarbon concentrations which may be attributed to fluctuating <br /> water table elevations For the most part, laboratory results indicate that influent TPHg and <br /> BTEX concentrations have been significantly reduced since system start-up <br /> RESNA personnel will continue with the quarterly monitoring program which will include <br /> reports detailing system performance We will continue to monitor system performance and <br />• 1321021QRTLY1lQR-1994 FNL 2 <br />