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CONCLUSIONS <br />Results of the first quarter 2012 groundwater sampling performed at the GCC Rio Grande <br />Cement Plant during March 2012 are presented herein. All analyses required were <br />performed as requested. <br />The Colorado DRMS has provided NPL standards for the GCC groundwater monitoring <br />project for four constituents of concern (sulfate, TDS, Radium 226 and Radium 228). The <br />TDS and Radium 228 numeric standards were exceeded during this sampling event. The <br />radium 228 exceedence appears to be an isolated event, and no trend is present. <br />TDS concentrations exceed DRMS NPL in two of the three compliance monitoring wells. <br />The exceedences mark the second consecutive events where TDS has exceeded NPLs at <br />wells MW -03 and MW-04. Two data points is the minimum possible data set than can be <br />represented as a trend. As such, GCC will continue to sample TDS on a quarterly basis to <br />determine if the trend continues. <br />GCC believes that elevated TDS concentrations are likely related to falling water levels in <br />the vicinity of the St Charles River compliance wells, and subsequent concentration of <br />dissolved constituents in the shallow aquifer. Dry conditions at the facility also minimize <br />the potential for any groundwater to reach the compliance wells from the cement plant, as <br />continuous saturated conditions between the plant and the compliance wells are unlikely to <br />exist (as shown by well MW -05) when water levels drop. <br />6 <br />