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NTUs) is comparable to historical values observed at that well, and is the lowest turbidity value
<br /> since November 2005. The first quarter 2010 field turbidity value at AMW-10 (170 NTUs) is
<br /> comparable to historical values observed at that well. The first quarter 2010 field turbidity value
<br /> at AMW-19 (5 NTUs) is comparable to historical values observed at that well, and is the lowest
<br /> turbidity value since November 2005.
<br /> Mann-Kendall / Sen's Slope analysis identified decreasing trends in the following inorganic
<br /> parameters: barium at AMW-10, bicarbonate at AMW-10, calcium at AMW-10 and AMW-11,
<br /> chloride at AMW-10, AMW-11, AMW-18, and AMW-19, hexavalent chromium at AMW-19,
<br /> magnesium at AMW-10 and AMW-11, nitrate at AMW-1, AMW-10, AMW-18, and AMW-
<br /> 1913R, field pH at AMW-1, AMW-18, and AMW-19, potassium at AMW-10, AMW-11, AMW-
<br /> 18, and AMW-1913R, sodium at AMW-10, AMW-18, and AMW-19, field specific conductance
<br /> at AMW-11, strontium at AMW-10, sulfate at AMW-1, AMW-18, AMW-19, and AMW-19BR,
<br /> field temperature at AMW-11, TDS at AMW-11, AMW-18, and AMW-19, and field turbidity at
<br /> AMW-1 and AMW-18. Carbonate at AMW-18 and hexavalent chromium at AMW-11 exhibited
<br /> apparent decreasing trends according to the Mann-Kendall / Sen's Slope analysis, but this trends
<br /> are due to historical decreases in the laboratory RL.
<br /> The field pH value observed at AMW-1 during the first quarter 2010 (6.7 s.u.) is comparable to
<br /> historical pH values observed at that well, and is within the National Secondary Drinking Water
<br /> Standard range (6.5 - 8.5 s.u.). The field pH value observed at AMW-18 during the first quarter
<br /> 2010 (7.56 s.u.) is comparable to historical pH values observed at that well, and is within the
<br /> National Secondary Drinking Water Standard range (6.5 - 8.5 s.u.). The field pH value observed
<br /> at AMW-19 during the first quarter 2010 (7.67 s.u.) is comparable to historical pH values
<br /> observed at that well, is the highest pH value since monitoring was initiated, and is within the
<br /> National Secondary Drinking Water Standard range(6.5 - 8.5 s.u.).
<br /> The following VOCs exhibited an increasing trend according to the Mann-Kendall / Sen's Slope
<br /> analysis: 1,1-dichloroethane at AMW-1 and AMW-19BR, cis-1,2-dichloroethene at AMW-1 and
<br /> AMW-10, tetrachloroethene at AMW-19, trichloroethene at AMW-1 and AMW-19, and vinyl
<br /> chloride at AMW-1.
<br /> The first quarter 2010 concentration of 1,1-dichloroethane at AMW-1 (2.6 ug/L) is comparable to
<br /> historical concentrations observed at that well. The first quarter 2010 concentration of 1,1-
<br /> dichloroethane at AMW-19BR (0.45 ug/L) is comparable to concentrations observed at that well
<br /> for the past six monitoring events. The first quarter 2010 concentration of cis-1,2-dichloroethene
<br /> at AMW-1 (3.6 ug/L) is comparable to historical concentrations observed at that well, and is well
<br /> below the National Primary Drinking Water Standard (70 ug/L). The first quarter 2010
<br /> concentration of cis-1,2-dichloroethene at AMW-10 (0.11 ug/L) is the lowest concentration
<br /> observed at that well since May 2008, and is well below the National Primary Drinking Water
<br /> Standard(70 ug/L).
<br /> The first quarter 2010 concentration of tetrachloroethene at AMW-19 (1.7 ug/L) is comparable to
<br /> concentrations observed at that well since November 2006, and is below the National Primary
<br /> Drinking Water Standard (5 ug/L). The first quarter 2010 concentration of trichloroethene at
<br /> AMW-1 (3.6 ug/L) is comparable to historical concentrations observed at that well, and is below
<br /> the National Primary Drinking Water Standard (5 ug/L). The first quarter 2010 concentration of
<br /> trichloroethene at AMW-19 (0.99 ug/L) is comparable to concentrations observed at that well
<br /> since August 2006, and is below the National Primary Drinking Water Standard (5 ug/L). The
<br /> first quarter 2010 concentration of vinyl chloride at AMW-1 (0.82 ug/L) is comparable to
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