Laserfiche WebLink
MW-5: <br /> MW-5 is an impacted well. Trend analysis is performed on MW-5 data for all constituents,rather <br /> than establishing concentration limits. Data analysis shows increasing trends in Chloride,TDS, <br /> Sulfate,Electrical Conductivity,Bicarbonate Alkalinity as CaCO3 and Total Alkalinity as CaCO3- <br /> Analysis indicates a decreasing trend in pH. The concentration trend for Calcium,Potassium, <br /> Magnesium and Sodium could not be determined due to insufficient data. <br /> Six VOCs (see Table 1)were reported this quarter from MW-5. One VOC (Methylene Chloride) <br /> was also found in quality control blanks and is a "false positive" result. Minus the false positive, <br /> only five confirmed VOCs were reported this quarter. This number is less than the seven VOCs <br /> reported the previous quarter. <br /> The trend analysis for VOC data indicates a decreasing trend for three and an increasing trend for <br /> 1 four. The trend analysis method will continue to be used quarterly-to evaluate concentrations of <br /> VOCs in MW-5. <br /> The LFG Collection System continues to effectively reduce the concentration of LFG (and <br /> associated VOCs) in the soil beneath the landfill. The trend in the number of VOCs ("false <br /> positives" ignored) verifies this finding. <br /> Year VOCs Reported in MW-5 <br /> 2001 42 <br /> 2002 29 <br /> 2003 24 <br /> Also,the mean of the VOCs reported per sampling event for the last six quarters (including this <br /> fourth quarter test results) is 7.5. The mean number of the VOCs reported per sampling event for the <br /> four quarters that preceded the installation of gas extraction system (July 2000 to April 2001) is 13 <br /> (Appendix E,Tabular Summary of Historical Monitoring Data). <br /> ' Deep Aquifer <br /> MW-6: <br /> Well MW-6 was sampled in October for the second time. Initial water samples were taken during <br /> the third quarter's monitoring event in August. <br /> Inorganic constituent concentrations are within expected ranges (Table 1), with the exception of pH <br /> (9.96). As mentioned in the previous report,the pH is much higher than the average pH(7.9) <br /> reported for monitoring well MW-3 before that well"went dry", in the third quarter of 1990. The <br /> pH level may be caused by the grout seal used to construct the well. The pH will be monitored <br /> closely. <br /> Corral Hollow Landfill 5 Department of Public Works/Solid Waste <br /> 4'Qtr/Annual 2003 Groundwater Monitoring County of San Joaquin-January 28,2004 <br />