ARCHIVED REPORTS_2008_22 - Laserfiche WebLink

Home Browse Search

corrective action monitoring well AMW-3 has been abandoned. The field results provided by ATC Associates, Inc.and laboratory results provided by BC Laboratories,Inc. for the first quarter 2008 corrective action sampling are summarized on Table 2.3. VOCs have been consistently detected in samples from corrective action monitoring wells AMW- 1, AMW-4, AMW-10, and AMW-11. AMW-5/5R, AMW-18, and AMW-19 have previously exhibited sporadic VOC detections. The historical groundwater data for the corrective action monitoring wells are presented in Appendix F. The data are graphed on time series concentration plots, included in Appendix G. For VOCs, only those VOCs that exhibited detections for the first quarter 2008 monitoring event were plotted. Historical data from the corrective action monitoring wells from March 1994 to the present were analyzed for temporal trend using Sen's Slope trend analysis. Graphs of the Sen's Slope analyses for corrective action monitoring wells are included in Appendix G. Table 2.4 summarizes the results of the corrective action monitoring well trend analysis. The following inorganic constituents exhibited an increasing trend according to the Sen's Slope analysis:barium at AMW- 1, AMW-5R, and AMW-18, bicarbonate at AMW-1, AMW-5R, and AMW-18, chloride at AMW-5R, nitrate at AMW-5R, field pH at AMW-5R, sodium at AMW-11, field specific conductance at AMW-1 and AMW-5R, sulfate at AMW-5R and AMW-10,TDS at AMR-5R,and field turbidity at AMW-10 and AMW-19. The first quarter 2008 concentration of barium at AMW-1 (0.31 mg/L) is comparable to concentrations observed at that well intermittently since May 2004, and is well below the National Primary Drinking Water Standard (2 mg/L). The first quarter 2008 concentration of barium at AMW-5R (0.34 mg/L) is comparable to concentrations observed at that well since August 2003, and is well below the National Primary Drinking Water Standard (2 mg/L). The first quarter 2008 concentration of barium at AMW-18 (0.15) is comparable to concentrations observed at that well intermittently since August 2005, and is well below the National Primary Drinking Water Standard(2 mg/L). The first quarter 2008 concentration of bicarbonate at AMW-1 (740 mg/L) is comparable to concentrations observed at that well intermittently since August 2003. The first quarter 2008 concentration of bicarbonate at AMW-5R (480 mg/L) is comparable to concentrations observed at that well intermittently since July 1995. The first quarter 2008 concentration of bicarbonate at AMW-18 (370 mg/L) is comparable to concentrations observed at that well consistently since February 2005. The first quarter 2008 concentration of chloride at AMW-5R (110 mg/L) is comparable to concentrations previously observed at AMW-5, and is below the National Secondary Drinking Water Standard (250 mg/L). The first quarter 2008 concentration of nitrate at AMW-5R(23 mg/L) is comparable to concentrations observed at AMW-5 during the past two monitoring events, and is above the National Primary Drinking Water Standard(10 mg/L). The field pH value observed at AMW-5R during the first quarter 2008 (7.18 s.u.) is comparable to pH values observed at AMR-5 intermittently since April 1999, and is within the National Secondary Drinking Water Standard range(6.5 -8.5 s.u.). The first quarter 2008 concentration of sodium at AMW-11 (71 mg/L) is comparable to concentrations observed at that well since August 2006. The first quarter 2008 field specific conductance value at AMW-1 (1,320 umhos/cm) is comparable to values observed at that well consistently since August 2005. The first quarter 2008 field specific conductance value at AMW-5R(1,390 umhos/cm) is comparable to values observed at AMW-5 intermittently since November 2003. 4