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Ki cm 0.001 sec – ft <br />V = — = [(0.04 —) * ] * 2835 � 0.32 ft / day <br />ne sec 0.35 cm – day <br />where: V= Groundwater flow velocity. <br />K = Hydraulic conductivity of the water -bearing unit (0.04 cm/sec). <br />i = Hydraulic gradient: i � 0.001 for the site during the current the third quarter 2012. <br />n, = Effective porosity (n, = 0.35); an estimated value. <br />The groundwater flow rate is calculated to be 0.32 feet/day (118 feet/year). <br />I1 i 1 1 1, i - . 1; <br />Field and laboratory results for the Austin Unit DMP wells for the third quarter 2012 are <br />summarized in Table 3-1. <br />Volatile Organic Compounds <br />As shown in Table 3-1, PCE was measured above the PQL in the samples collected from <br />wells AMW-13 and AMW-14; and trichloroethene (TCE) was measured above the PQL <br />in the sample collected from well AMW-13. In addition, three or more VOCs were <br />measured at trace concentrations in the samples collected from wells AMW-6 and <br />AMW-13. <br />is Concentration Limit Comparison <br />For the DMP wells at the Austin Unit, CLs are calculated for the water quality protection <br />standards (WQPS). The CLs shown in Table 3-1 were calculated by Herst & Associates <br />using Sanitas®, a state -approved statistical software program; the results of the statistical <br />analyses performed by Herst & Associates are presented in Appendix D. Based on a <br />comparison of the data obtained during the third quarter 2012 monitoring period, the <br />following analytes were found to exceed a CL. <br />CONSTITUENT <br />I Concentration <br />Limit <br />DMP MONITORING WELL <br />AMW-2g AMW-6 AMW-7 I AMW-12 I AMW-13 <br />I AMW-14 <br />MONITORING PARAMETERS (m fl) <br />Barium 0.2214 <br />1 0.280 <br />1 0.280_t <br />0.290 <br />Chloride 74.36 <br />1 88 <br />1 <br />100 <br />Chromium (Hexavalent) 0.004896 <br />0.0049 <br />Potassium 10.88 11 <br />VOLATILE ORGANIC COMPOUNDS /I <br />etrachloroethene <br />1 0.5 1 <br />6.2 <br />1 0.86 <br />Trichloroethene <br />1 0.5 1 <br />1.8 <br />NOTES: (a) - Background Well. <br />Trend Analyses <br />In order to evaluate changes in water quality in DMP wells at the Austin Unit, historical <br />trends in groundwater were evaluated beginning in 1994 when the groundwater treatment <br />facility began operation. For constituents whose historical data consists primarily of non- <br />CA2012-0025TA3Q12.doc 9 Geo -Logic Associates <br />