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Mr Chuck Carmel Apnl 22, 1993 Page 2 i� Results The general groundwater flow across the site is to the south-southwest with an average hydraulic gradient of 0 003 Water level data are listed in Table 1 Table 2 shows past and present hydraulic gradients and groundwater flow directions. Figure 1 illustrates groundwater contours and the groundwater flow direction Well W-2B was not used for contouring, as this well is completed in a deeper zone than the other wells Current and historical analytical results are summarized in Table 3 The November 1992 analytical results are shown on Figure 2 The complete laboratory report for the November 1992 sampling is presented in Exhibit A BETX and TPH-G were not detected in any of the samples, the detection limits for the BETX constituents and TPH-G are 0 5 and 50 pg/l, respectively A summary of the remediation system operations for the first quarter is provided in Table 4 for soil and Table 5 for groundwater Figures 3 and 4 summarize the cumulative amount of TPH-G removed from the soil and groundwater since the soil vapor and groundwater treatment systems were started in July 1991 and October 1992, respectively Discussion The direction of groundwater flow at this site ranges from southeast to southwest under a gradient ranging from 0 035 to 0 002. The current south-southwest flow direction and gradient of 0 003 are within the ranges previously reported. On February 22, 1993, the depth to water ranged from 62 57 feet to 65 43 feet. Water levels in the monitoring wells increased an average of 2 38 feet between November 17, 1992 and February 22, 1993 BETX and TPH-G constituents were not detected in groundwater samples collected from any of the monitoring wells for the first time since monitoring began in 1987. Status of Site Remediation A soil vapor extraction and treatment system has been operating at this site since July 1991. As of March 1, 1993, approximately 39,900 pounds of hydrocarbons had been extracted and treated from site soils A groundwater extraction and treatment system has been in operation at the site since October 1992 As of March 1, 1993, a total of approximately 154,400 gallons of groundwater had been extracted and treated. In an effort to increase tnfluent concentrations to the groundwater treatment system,groundwater extraction is being pulsed on a weekly basis (on for a week, off for a week) 0 Brown and Caldwell 748"tEP0RTS�FEH93QTR RPT Consui ants