ARCHIVED REPORTS_2011_1 - Laserfiche WebLink

Home Browse Search

3.0 SOLID WASTE MONITORING The French Camp Landfill has been formally closed and no longer receives waste (Appendix A). .0 WATER QUALITY MONITORING .1 SAMPLING AND LABORATORY ANALYSES All of the groundwater monitoring wells were sampled on February 22, 2011 and surface water monitoring points were sampled on February 28, 2011. Quarterly depth-to-water measurements and stream gauging was performed on February 22, and May 22,2011. 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- 2007-0046, as summarized in Table 1. Water quality samples were also analyzed in the field for oxygen reduction potential, turbidity,temperature, specific conductance, and pH and these 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, surface water sampling stations, and soil-pore gas sampling stations are summarized in Tables 2 through 6. 4.2QA/QC RESULTS The quality assurance/quality control (QA/QC)program completed for the monitoring event included analyses of one duplicate sample, one field (ambient)blank, one trip blank, and laboratory method blanks. The trip and field blanks were analyzed for volatile organic compounds (VOCs)by EPA Method 8260,while the laboratory method blanks were analyzed for all of the analytes included in the monitoring program. During the monitoring period, toluene was detected at a trace concentration in the trip blank. However,no VOCs were detected in any of the primary samples collected during the monitoring period. In addition, chloride was detected in the method blank at a concentration greater than 10%of the reported values in surface water samples SW-1, SW-2, and SW-3. These chloride results were flagged as suspected laboratory contaminants. A duplicate groundwater sample was collected from well MW-8A and was labeled MW-8A-DUP. Duplicate groundwater test results are presented along with the primary data in Table 2. Comparison of the primary and duplicate sample results, when both results are measurable concentrations above the PQL, indicates good agreement (within 3%). Review of the semiannual sampling dates and laboratory analytical certificates indicates that all of the laboratory analyses were completed within required holding times. Based on the results of the laboratory QA/QC analyses, it is concluded that the ®:\2011-0051ec_esnu.aocx 2 GeoLoglc Associates