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For VOCs, only those compounds that exhibited detections at corrective action monitoring wells
<br /> during the first quarter 2012 monitoring event were plotted.
<br /> During the first quarter 2012, there were no VOCs detected above the laboratory RL in wells
<br /> AMW-4, AMW-5R, AMW-11, AMW-18, or AMW-19. 1,1-Dichloroethane, 1,4-
<br /> dichlorobenzene, benzene, chlorobenzene, cis-1,2-dichlorobenzene, tetracholorethene,
<br /> trichloroethene, and vinyl chloride were detected at AMW-1 above the laboratory RL.
<br /> Trichloroethene was detected at AMW-10 above the laboratory RL. Dichlorodifluoromethane,
<br /> tetrachloroethene, and trichloroethene were detected at AMW-19BR above the laboratory RL.
<br /> Historical data from the corrective action monitoring wells from March 1994 to the present were
<br /> analyzed for temporal trends using Mann-Kendall / Sen's Slope trend analysis. Graphs and
<br /> summary tables of the Mann-Kendall / Sen's Slope analyses for corrective action monitoring
<br /> wells are presented in Appendix G. For constituents whose historical data consist primarily of
<br /> non-detects (carbonate alkalinity, oil and grease, volatile petroleum hydrocarbons, and VOCs),
<br /> trend evaluation was performed on data from the earliest detection through the present. Wells
<br /> with no historical detections for a constituent were not evaluated for trends.
<br /> Table 2.3 summarizes the results of the corrective action monitoring well trend analysis. Mann-
<br /> Kendall / Sen's Slope analysis identified significant increasing statistical trends in the following
<br /> inorganic constituents: barium at AMW-1 and AMW-19; bicarbonate alkalinity at AMW-1,
<br /> AMW-5R, and AMW-18; chloride at AMW-5R and AMW-19BR; nitrate at AMW-4 and AMW-
<br /> 5R; field pH at AMW-4, AMW-5R, AMW-11, and AMW-19BR; field specific conductance at
<br /> AMW-1 and AMW-5R; sulfate at AMW-5R and AMW-10; TDS at AMW-5R; and field turbidity
<br /> at AMW-5R and AMW-10. Carbonate at AMW-5R exhibited an apparent increasing trend
<br /> according to the Mann-Kendall/Sen's Slope analysis,but this trend is due to a historical increase
<br /> in the laboratory RL.
<br /> Mann-Kendall / Sen's Slope analysis identified significant decreasing statistical trends in the
<br /> following inorganic constituents: barium at AMW-10 and AMW-11; bicarbonate alkalinity at
<br /> AMW-4 and AMW-10; calcium at AMW-4 and AMW-10; carbonate alkalinity at AMW-11 and
<br /> AMW-18; chloride at AMW-4, AMW-10, AMW-11, and AMW-18; hexavalent chromium at
<br /> AMW-19 and AMW-19BR; magnesium at AMW-4, AMW-5R, AMW-10, and AMW-11; nitrate
<br /> at AMW-1, AMW-10, AMW-18, AMW-19, and AMW-19BR; field pH at AMW-1; potassium at
<br /> AMW-4, AMW-10, AMW-11, AMW-18, and AMW-19BR; sodium at AMW-10, AMW-18,
<br /> AMW-19, and AMW-19BR; field specific conductance at AMW-4, AMW-10, and AMW-11;
<br /> strontium at AMW-4 and AMW-10; sulfate at AMW-1, AMW-18, AMW-19, and AMW-19BR;
<br /> field temperature at AMW-4 and AMW-11; TDS at AMW-4, AMW-10, AMW-11, and AMW-
<br /> 18; and field turbidity at AMW-4.
<br /> Mann-Kendall / Sen's Slope analysis identified significant increasing statistical trends in the
<br /> following VOCs: 1,1-dichloroethane at AMW-1; chlorobenzene at AMW-1; and cis-1,2-
<br /> dichloroethene at AMW-1.
<br /> Mann-Kendall / Sen's Slope analysis identified significant decreasing statistical trends in the
<br /> following VOCs: 1,1-dichloroethane at AMW-4, AMW-10, and AMW-11; 1,2-dichloropropane
<br /> at AMW-4 and AMW-11; 1,3-dichlorobenzene at AMW-1; 1,4-dichlorobenzene at AMW-4; cis-
<br /> 1,2-dichloroethene at AMW-4, AMW-11, and AMW-19BR; dichlorodifluoromethane at AMW-1,
<br /> AMW-4, AMW-10, and AMW-11; tetrachloroethene at AMW-4, AMW-5R, AMW-10, and
<br /> AMWA 1;trans-1,2-dichloroethene at AMW-4 and AMW-11; trichloroethene at AMW-4,AMW-
<br /> 10, and AMW-11; and vinyl chloride at AMW-4.
<br /> 5
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