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First Quarter,2002 Quarterly Groundwater Monitoring Report Eckert Cold Storage,Manteca,California Page 3 ft./ft. to the northwest, as shown. Groundwater elevation data for February 27, 2002 using prior and • current elevation data for the monitor wells is in presented in Table 1, below. Table 1 -Groundwater Elevation Data (February 27,2002) Monitoring Screened Depth to Prior TOC Groundwater Current TOC Groundwater Well Interval Groundwater Elevation' Elevation2 Elevation Elevations (bgs) MW-1 I3 -28 16.49 35.80 19.31 38.09 21.60 MW-2 15-30 16,22 35.61 19.39 37.90 21.68 MW-3 I5_-3 0 16.69 36.02 19.33 38.31 21.62 MW-4 12-27 16.41 35.50 19.09 37.84 21.43 MW-5 14-334 19.59 38.70 19.11 41.22 21.63 MW-6 13 -33 16.00 35.37 I9.37 37.65 21.65 MW-7 13 -33 16.55 35.94 1939 38.22 21.67 MW-$ 1 17 - 37 16.46 35.66 19.20 37.95* 21.49 Prior TQC Elevation:Elevation data provided by others Groundwater elevation based on prior TOC elevation data provided by others 'Current TOC Elevation:Elevations are measured from the top of the well casing and are referenced to NGS Benchmark HS4486,elevation 35.03 feet using NAVD 88 datum. 'Groundwater elevation based on TOC elevation data provided by Condor. *Condor surveyed the well casing at 37.95 feet prior to lowering the well casing on February 27,2002 to allow the well to be properly locked and secured in the Christy box.After lowering,Condor surveyed the casing at 37.76 feet. All measurements are in feet.. LABORATORY ANALYTICAL RESULTS The groundwater samples collected from the monitor wells were analyzed for BTEX, TPH-G, and • selected gasoline oxygenates/additives including MTBE by Excelchem Laboratories, Inc, of Roseville, California. Upon initial review of the laboratory results, Condor requested that Exelchem further evaluate the sample result chromatograms. Condor did not believe that the BTEX results for the sample collected from MW-1 using the EPA Method 8260 analysis were consistent with the TPH-G result for the same sample using EPA Method 8015M. The BTEX results for MW-I were also inconsistent with historical laboratory data for that monitor well. Upon further review by Exelchem of the sample chromatograms, they indicated that there was difficulty with the analysis of the MW-1 sample. They subsequently re- analyzed the MW-1 sample using EPA Method 8020 and again using EPA Method 8260 and reported revised BTEX results from the re-analysis. The current laboratory analytical results (Table 2, on the following page) indicate petroleum hydrocarbon concentrations detected in the sample collected from MW-1 generally increased with respect to the previous sampling event conducted on December 17, 2001. BTEX concentrations detected in the samples collected from MW-3 and MW-5 generally decreased with respect to the previous sampling event, while the concentrations of oxygenates/additives generally increased. BTEX constituents were not detected at or above the laboratory reported detection limits in the sample collected from MW-4. This was the first time that some or all of the BTEX constituents were not detected in MW-4 since the June 2000 monitoring event. Concentrations of TPH-G and 1,2-DCA in the sample from MW-4 were consistent with previous monitoring events. Petroleum hydrocarbons were not detected at or above the laboratory reported detection limits in the samples collected from MW-6 and MW-7. Petroleum hydrocarbon concentrations detected in the sample collected from MW-8 generally decreased with respect to the previous sampling event. Historical groundwater monitoring data is included in Attachment C. Laboratory certificates of analyses and the chain-of-custody record are included in Attachment D. �.M1 CONDOR