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Ki cm 0.001 sec– ft V = —= [(0.04 —)* ]* 2835 , 0.32ft/day ne sec 0.35 cm – day where: V=Groundwater flow velocity. K=Hydraulic conductivity of the water-bearing unit(0.04 cm/sec). i=Hydraulic gradient: i;z 0.001 for the site during the current the first quarter 2013. n,=Effective porosity(n,=0.35);an estimated value. The groundwater flow rate is calculated to be 0.32 feet/day (118 feet/year). Detection Monitoring Program Field and laboratory results for the Austin Unit DMP wells for the first quarter 2013 are summarized in Table 3-1. Non-Statistical Data Analysis The non-statistical VOC water analyses performed on the DMP well data indicates that there were three non-statistical exceedances for VOCs. The non-statistical exceedances were identified at well AMW-6 as a result of the detection of two VOCs (DCDFM and PCE) at estimated trace concentrations; at well AMW-13 as a result of the detection of DCDFM, PCE, and TCE at concentrations above the PQL and 1,1-dichloroethane (1,1- DCA), cis-1,2-dichloroethene (cis-1,2-13CE), and trichlorofluoromethane (TCFM) at estimated trace concentrations; and for well AMW-14 as a result of the detection of PCE above the PQL and TCE at an estimated trace concentration. Trend analyses indicate that statistically significant increasing temporal trends were calculated for PCE and TCE in well AMW-13. Trend analyses are included in Appendix D. These results are similar to previous results and it is recommended that wells AMW-6, AMW-13, and AMW-14 be re-designated as CAP wells since they have historically contained VOCs. Concentration Limit Thresholds As specified in RWQCB Order No. R5-2003-0049 the routine monitoring parameters obtained during the first quarter 2013 monitoring period were compared to interwell CLs established for the Austin Unit DMP wells. The CLs shown in Table 3-1 were calculated using Sanitas, a state-approved statistical software program. Details regarding the concentration limit calculations are discussed in Appendix D. Based on a comparison of the data obtained during the first quarter 2013 monitoring period, inorganic CLs were exceeded for barium in the samples collected from wells AMW-12, AMW-13, and AMW-14; chloride in wells AMW-12 and AMW-14; and for hexavalent chromium in well AMW-7. For any inorganic monitoring parameter that exceeded a CL, Mann- Kendall / Sen's Slope trend analyses was performed to determine if statistically significant increasing temporal trends were evident in the data. Trend analyses indicate statistically significant increasing temporal trends for barium and chloride concentrations C:\2013-0021\FA_iQ13.doe 10 Geo-Logic Associates