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Date. July 27,2005 <br /> Quarter* 20d Quarter,2005 <br /> . • The reported results for ethanol in samples MW-1, MW-2, MW-3, MW-4, MW-5, MW-G, MW-7, <br /> VW-1, and VW-2 may be biased low because the associated continuing calibration standard was <br /> outside of acceptance criteria <br /> • The reported result for gasoline range organics (GRO) in sample MW-6 is due to chromatographic <br /> peaks present in the gasoline quantitation range,however,the peaks present do not resemble the pattern <br /> for gasoline <br /> • The elevated reporting lirnits were the result of dilutions performed by the laboratory in order to <br /> quantitate a target analyte <br /> DISCUSSION: <br /> GRO, benzene, toluene, ethylbenzene, total xylenes (BTEX), MtBE, tert-butyl alcohol (TBA), di-isopropyl ether <br /> (DIPE), and 1,2-dichlorothane (1,2-DCA) were detected above laboratory reporting hrmts in groundwater samples <br /> collected from site wells this quarter GRO, benzene, and MtBE concentrations in the monitoring wells(MW) were <br /> generally consistent with historical data Low-level concentrations of Mtl3E in MW-I and benzene in MW-3 were <br /> detected above laboratory reporting limits for the first time since December 2001 and June 1999,respectively MtBE <br /> was not detected in MW-4 this quarter GRO,benzene, and MtBE concentrations in the vapor extraction wells(VW) <br /> were generally consistent with historical data with a few exceptions GRO concentrations in VW-I decreased relative <br /> to previous quarters In VW-8, GRO concentrations increased relative to the previous quarter but, per the previous <br /> section, this result should be considered estimated Additionally in VW-8, benzene concentrations decreased GRO <br /> and benzene concentrations in VW-10 and benzene concentrations in VW-12 decreased GRO, benzene, and MtBE <br /> concentrations in the nucrosparge (MS) wells were generally consistent with historical data In MS-lA and MS-113, <br /> GRO and benzene concentrations increased but are generally consistent with concentrations reported during first <br /> quarter 2004 In MS-2A, benzene was not detected In MS-3A, GRO and benzene concentrations decreased relative <br /> • to the previous quarter and MtBE increased from 18 pg/L,reported during first quarter 2004,to 71 jig/1-this quarter, <br /> the highest concentration reported since sampling began in December 2002 <br /> The average depth to water at the site was approximately 42 feet bgs during this quarter Groundwater elevations <br /> generally decreased less than one foot relative to the previous sampling event The inferred direction of groundwater <br /> flow across the site ranged from the northeast to southeast with an average hydraulic gradient that ranged from 0 001 <br /> to 0 002 ft/ft <br /> This report is based on data,site conditions, and other information that are generally applicable as of the date of the <br /> report,and the conclusions and recommendations herein are therefore applicable only to that time frame <br /> TABLES <br /> Table I Groundwater Monitoring and Analytical Data <br /> Table 2 Fuel Oxygenates Analytical Data <br /> Table 3 Groundwater Gradient Data <br /> FIGURES <br /> Figure I Groundwater Elevation Contours <br /> Figure 2 Groundwater Analytical Summary <br /> • <br /> K 1Wprocess135 BP ARC0502 MQaaner[y1200512 QTR 05\2130 GWMR 2"doe Page 2 <br />