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2.2 Groundwater Elevation and Well Depth Data Free product was not, nor ever has been observed among the wells, based on the measurements obtained utilizing the oil/water interface probe and the visual observations Groundwater elevations remained relevant among the wells, but decreased approximately 2 76 feet from the previous event performed in June 2004 The elevations ranged from -31 50' to –32 43' mean sea level (MSL) The groundwater flow direction is easterly to southeasterly at a gradient of approximately 2 94 x 10-3 feet per linearTaoi ' The well depth measurements at the air sparging locations SP-1, SP-5, and SP-6 indicated an appreciable amount of fill material has entered the wells The sparging wells were never intended to be used for monitoring purposes and were never developed as such Furthermore, the screen placements of these air-sparging points were selected to facilitate the injection of air into the subsurface and not the collection of representative groundwater samples The tops of the screens in the air sparging points are approximately 20 feet below the groundwater table If further sampling or remediation activities are to be ' conducted at these locations, the air sparge points will need to be developed— 2.3 BTEX and TPH-G Analytical Results Typical petroleum hydrocarbons (BTEX and TPH-G) were detected in the groundwater samples from the following wells MW-1, MW-7, MW-11, MW- 12, SP-1, SP-2, SP-4, SP-6, PZ-1, and PZ-2 There were no detectable BTEX or TPH-G concentrations measured in the samples collected from wells MW- 5, MW-8, MW-10, SP-3, and SP-5 _1/ The benzene concentrations increased in wells MW-1, MW-7, MW-11, MW- 12, SP-1, SP-4, SP-6, and PZ-2 The detectable benzene concentrations ranged from 19 µg/L at well MW-12 to 1,800 gg/L at well PZ-1 The remaining analytes varied between the wells Some analytes increased, while 1 others decreased among the wells The TPH-G concentrations increased in wells MW-11, MW-12, SP-1, SP-4, and PZ-1 The remaining wells remained stable or decreased in concentration The detectable TPH-G concentrations ranged from 160 µg/L at well MW-12 to 20,000 µg/L at well SP-1 The current BTEX concentrations were evaluated against the California Drinking Water Maximum Contaminant Levels (MCL)s The MCLs for benzene, toluene, ethylbenzene, and xylenes in groundwater are 1 µg/L, 150�h\ 9 ' Quarterly Groundwater Monitoring Report October 2004 The Earthgrams Company Facility 26-11 South Airport Way-Stockton,California Prepared for SARA LEE BAKERY GROUP Prepared by Philip Services Corp H%W624001321121382EG1Stockton Airport Way\investigation and Quarterly ReporislQuarterly Report 10_2004 doe December 09,2004