Laserfiche WebLink
Ki cm 0.002 sec– ft <br /> V = —_ [(0.04 —)* ]*2835 ;ze 0.65 ft l 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-0.002 for the site during.the current the first quarter 2007. <br /> ne=Effective porosity(ne=0.35);an estimated value. <br /> The groundwater flow rate is calculated to be 0.65 feet/day(237 feet/year). <br /> 3.1.4 Detection Monitoring Program <br /> Field and laboratory results for the DMP wells for the first quarter 2007 are summarized <br /> in Table 3-1 and time-series plots are presented in Appendix D. As shown in Table 3-1, <br /> two VOCs were measured in DMP well AMW-13 including PCE measured above the <br /> PQL; and six VOCs were measured in DMP well AMW-14,with four measured above <br /> the PQL. For the DMP wells at the Austin Unit, CLs are used for the water quality <br /> protection standards(WQPS). The CLs shown in Table 3-1 were calculated by Herst& <br /> Associates using Sanitas®, a state-approved statistical software program. Based on a <br /> comparison of the data obtained during the first quarter 2007 monitoring period,the <br /> following analytes were found to equal or exceed a CL. The results of the statistical <br /> analyses performed by Herst&Associates are presented in Appendix D. <br /> CONSTITUENT Concentration DMP MONITORING WELL <br /> Limit AMW-2 AMW-6 I AMW-7 AMW-12 AMW-13 AMW-14 <br /> ONITORING PARAMETERS tm <br /> Barium 1 0.2491 1 1 0.270 <br /> hmmium,Hexavalent 1 0.00514 1 0.0057 1 0.0060 <br /> VOLATILE ORGANIC COMPOUNDS <br /> 1 -Dichloro ro ane 0.5 1 1 0.60 <br /> Dichlorodifluoromethane 0.5 0.73 <br /> etrachloroethene 0.5 1.9 12 <br /> Trichloroethene 0.5 1.1 <br /> NOTES: (B)-Background Well. <br /> DMP-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. The observed groundwater quality constituent trends were <br /> evaluated using Sen's Slope trend analyses to determine if significant increasing or <br /> decreasing trends were evident in the data. Trend analyses,performed by Herst& <br /> Associates, are presented in Appendix D and summarized below. Wells and analytes not <br /> discussed below either do not show significant trends (rising or falling) or have too few <br /> data points to establish meaningful trends. As shown in the following table, no <br /> increasing trends were noted for VOC constituents, and none of the constituents that <br /> exhibited an increasing trend exceeded a CL. In addition, decreasing trends were noted <br /> for PCE and TCE in DMP well AMW-14. <br /> D:12007 0043\ForwardAusttn wo7.doc <br /> 10 Geologic Associates <br />