ARCHIVED REPORTS_2011_17 - Laserfiche WebLink

Home Browse Search

dichloroethene at AMW-1 and AMW-10; dichlorodifluoromethane at AMW-19BR; tetrachloroethene at AMW-19; and trichloroethene at AMW-19. Mann -Kendall / Sen's Slope analysis identified significant decreasing statistical trends in the following VOCs: 1,1-dichloroethene at AMW-4, AMW-10, and AMW-11; 1,2 -dichlorobenzene at AMW-1; 1,4 -dichlorobenzene at AMW-4; benzene at AMW-4; cis-1,2-dichloroethene at AMW-4 and AMW-11; dichlorodifluoromethane at AMW-1, AMW-4, AMW-10, and AMW-I 1; tetrachloroethene at AMW-4, AMW-10, and AMW-11; trans-1,2-dichloroethene at AMW-4; and trichloroethene at AMW-4, AMW-10, and AMW-11. The second quarter 2011 concentration of arsenic at AMW-10 (0.0052 mg/L) is within the range of concentrations observed at that well since April 1995 (0.0016 to 0.0061 mg/L), and is below the National Primary Drinking Water Standard of 0.01 mg/L. The increasing trend for arsenic at AMW-10 is not observed when the data are limited to the period of February 2006 to May 2011, indicating that concentrations have stabilized in the past five years. The second quarter 2011 concentration of barium at AMW-I (0.49 mg/L) is below the National Primary Drinking Water Standard of 2 mg/L. The increasing trend for dissolved barium at AMW-1 is not observed when the data are limited to the period of August 2005 to May 2011, indicating that concentrations have stabilized in the past six years. The second quarter 2011 concentration of bicarbonate alkalinity at AMW-1 (920 mg/L) is within the range of concentrations observed at that well since June 1994 (264 to 1,300 mg/L). The increasing trend for bicarbonate at AMW-1 is not observed when the data are limited to the period of December 1994 to May 2011, indicating that concentrations have stabilized in the past seventeen years. The second quarter 2011 concentration of bicarbonate alkalinity at AMW-5R (380 mg/L) is within the range of concentrations observed at that well since March 1994 (148 to 550 mg/L). The increasing trend for bicarbonate at AMW-5R is not observed when the data are limited to the period of December 1994 to May 2011, indicating that concentrations have stabilized in the past seventeen years. The second quarter 2011 concentration of chloride at AMW-5R (76 mg/L) is within the range of concentrations observed at that well since March 1994 (1.24 to 130 mg/L), and is below the National Secondary Drinking Water Standard of 250 mg/L. The increasing trend for chloride at AMW-5R is not observed when the data are limited to the period of May 2000 to May 2011, indicating that concentrations have stabilized in the past eleven years. The second quarter 2011 concentration of nitrate at AMW-4 (2.1 mg/L) is within the range of concentrations observed at that well since March 1996 (<0.012 to 5.7 mg/L), and is below the National Primary Drinking Water Standard of 10 mg/L. The increasing trend for nitrate at AMW-4 is not observed when the data are limited to the period of April 2002 to May 2011, indicating that concentrations have stabilized in the past nine years. The second quarter 2011 concentration of nitrate at AMW-5R (14 mg/L) is within the range of concentrations observed at that well since March 1994 (<0.012 to 32 mg/L), but is above the National Primary Drinking Water Standard of 10 mg/L. However, the increasing trend for nitrate at AMW-5R is not observed when the data are limited to the period of February 2004 to May 2011, indicating that concentrations have stabilized in the past seven years. The second quarter 2011 field pH value at AMW-4 (7.49 s.u.) is within the range of values observed at that well since March 1996 (6.05 to 8.41 s.u.), and is within the National Secondary Drinking Water Standard range of 6.5 to 8.5 s.u. The increasing trend for field pH at AMW-4 is