Laserfiche WebLink
concentrations observed at that well for the past three monitoring events, and is well below the <br /> National Primary Drinking Water Standard(70 ug/L). <br /> The third quarter 2009 concentration of tetrachloroethene at AMW-19 (1.9 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 third quarter 2009 concentration of trichloroethene at <br /> AMW-19 (0.98 ug/L) is comparable to concentrations observed at that well since November <br /> 2006, and is below the National Primary Drinking Water Standard (5 ug/L). The third quarter <br /> 2009 concentration of trichloroethene at AMW-19BR (5.2 ug/L) is comparable to concentrations <br /> observed at the well for the past three monitoring events, and is slightly above the National <br /> Primary Drinking Water Standard (5 ug/L). The third quarter 2009 concentration of vinyl <br /> chloride at AMW-1 (0.62) is comparable to concentrations observed at that well intermittently <br /> since October 2001, and is below the National Primary Drinking Water Standard(2 ug/L). <br /> Sen's Slope analysis identified decreasing trends in the following VOCs: 1,1- <br /> dichlorochloroethane at AMW-4, AMW-10, and AMW-11, 1,4-dichlorobenzene at AMW-4, <br /> benzene at AMW-4, cis-1,2-dichloroethene at AMW-4 and AMW-11, dichlorofluoromethane at <br /> AMW-1,AMW-4, AMW-10, and AMW-11,tetrachloroethene at AMW-4,AMW-10, and AMW- <br /> 11, trans-1,2-dichloroethene at AMW-4, trichloroethene at AMW-4 and AMW-11, and vinyl <br /> chloride at AMW-4. The following organic constituents exhibited an apparent decreasing trend <br /> according to the Sen's Slope analysis, but this trend is due to a historical decrease in the <br /> laboratory PQL: 1,3-dichlorobenzene at AMW-1, 1,4-dichlorobenzene at AMW-1, benzene at <br /> AMW-1,tetrachloroethene at AMW-5R, and trichloroethene at AMW-5R. <br /> 6 <br />