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RESULTS OF CERTIFIED ANALYSIS OF GROUNDWATER SAMPLES <br /> MONITOR WELLS <br /> Monitor wells MW2, MW3, MW4, and MW5 penetrated both the A and B zones <br /> Contaminants found in these wells would mix with the groundwater of both zones <br /> Figure 6A represents the hydrocarbon groundwater plume in the A zone and shows an <br /> elongated plume extending west of MW2 out to "Geoprobe" hole P9 were degradation <br /> has left only minor TPHg (470 ug/L), Toluene (0 65 ug/L) and tert-Butanol, the <br /> degradation byproduct of MTBE (I 1 ug/L) The newly installed temporary piezometers <br /> PZ1A and PZ2A contained the highest concentration of hydrocarbons with 140,000 ug/L <br /> and 62,000 ug/L TPHg respectively <br /> Figure 6B represents the hydrocarbon groundwater plume in the B zone and shows a <br /> similar elongated plume extending west from MW2 out to "Geoprobe" hole P9 where <br /> degradation has left only minor amounts of Toluene (0 81 ug/L), Xylenes (0 83 ug/L) <br /> and MTBE (1 6 ug/L) Again the highest concentrations are associated with the newly <br /> installed temporary piezometers PZ I B and PZ2B with 40,000 ug/L and 16,000 ug/L <br /> TPHg respectively <br /> Figure 7 illustrates the subsurface lithology and the extent of the A and B zones <br /> groundwater plumes within the A and B zones Also shown in cross section is the extent <br /> of the excavation as of February 28, 2003 <br /> Figure 4C illustrates the site conditions on March 10, 2003 and shows the contour <br /> elevations above surface of the excavated soil pile and the area that has been excavated <br /> and backfilled along with the placement of traffic boxes and laterals within the excavated <br /> area for future well access points <br /> PUMP TEST FINDINGS <br /> The pump test was conducted as four separate tests because of the existence of two <br /> distinct water bearing zones, see Appendix D, <br /> Step Drawdown Test RWIA <br /> Step Drawdown Test RW1B <br /> 24 Hour Constant Rate RW 1 A <br /> 24 Hour Constant Rate RW1B <br /> ZONE A <br /> The Step Drawdown tests were performed on the two separate water bearing zones to <br /> determine at what rate to conduct the 24 hours Constant Pump Rate tests Well RW I A is <br /> screened across the A zone and the step drawdown test was initiated at a pump rate of 0 5 <br /> gallons per minute (gpm) and was increased in 0 5 increments At 14 gpm the the pump <br /> 8 Update Status March 2003 <br />