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4.0 SOIL-PORE GAS MONITORING Soil-pore gas monitoring at the French Camp Landfill is monitored under a separate contract and reported under separate cover. 5.0 WATER QUALITY MONITORING 5.1 SAMPLING AND LABORATORY ANALYSES All of the groundwater monitoring wells and surface water monitoring points were ' sampled on May 24, 2006. Prior to collection of samples, depth-to-water measurements were recorded for all groundwater monitoring wells. A single sample set was collected from each sampling point (groundwater,leachate, and surface water) and analyzed for the parameters stipulated in RWQCB Order No.R5- 2004-0159, and are summarized in Table 1. Water quality samples were also analyzed in ' the field for dissolved oxygen,turbidity, temperature, specific conductance, and pH and the field measurements were recorded on well data sheets. The groundwater monitoring wells and surface water monitoring points were sampled in accordance with the sampling and analysis procedures detailed in Appendix B. Well data sheets,raw laboratory data, certificates of analyses, and chain-of-custody records for the sampling program are included in Appendix C. The laboratory analyses and field results for groundwater wells and surface water sampling stations are summarized in Tables 2 through 5. 5.2 QA/QC RESULTS The quality assurance/quality control (QA/QC)program completed for the secondq uarter 2006 water quality monitoring event included analyses of one duplicate sample, one field (ambient)blank, one trip blank, and one laboratory method blank. The trip, field, and equipment were analyzed for volatile organic compounds (VOCs)by EPA Method 8260. Method blanks were analyzed for all of the monitoring parameters along with the primary ' samples. Low-level VOCs including benzene, ethylbenzene, toluene, and total xylenes were detected in QA/QC ambient and trip blank samples during the second quarter 2006 monitoring period. However,with the exception of surface water sample SW-2 and the leachate sample collected from well MW-lA, these suspected field contaminants were not detected in the primary samples collected. Historically, these VOCs have been detected in the sample collected from well MW-lA, so these detections were not flagged as suspected field contaminants. The trace level concentration of toluene in surface water sample SW-2 was flagged as a suspected field contaminant. ' A duplicate groundwater sample was collected from well MW-9B. Duplicate groundwater test results are presented along with the primary data in Table 2. Comparison of the primary sample with the duplicate sample indicates good agreement (less than 10%) for the water quality constituents. D:\2003_021\FC_9p06.doc 2 GeoLogic Associates