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INTRODUCTION <br />Contour Consulting Engineering, LLC, (Contour) collected groundwater samples at the <br />GCC Rio Grande Limestone Mine on July 10, 2008. The samples were collected to <br />satisfy quarterly monitoring permit requirements, as stipulated by the Colorado Division <br />of Minerals and Geology (DMG). <br />WORK PERFORMED <br />Contour collected groundwater samples from three shallow alluvial monitoring wells <br />(MW002, MW003, and MW004) in the vicinity of the St. Charles River. <br />Production/drinking water wells (DW001 and DW002) that were sampled during the first <br />quarter 2008, did not require sampling during the second quarter. The alluvial wells <br />represent downgradient conditions with respect to the Cement Plant operations. Newly <br />installed well MWOOIA is completed in the Codell Sandstone. This well was determined <br />to be dry during the first quarter 2008. Approximately 4 feet of water was measured in <br />this well during the second quarter. One full bailer of very clear water was removed <br />from the well, and then the well went dry. It is likely that the water produced in the well <br />was a result of formation condensation. Samples were not collected from MWOO IA. <br />The locations of all wells are provided in Figure 1. <br />Depth-to-groundwater measurements were performed at each alluvial well prior to <br />sampling. Wells were also sounded to determine total depth. The volume of standing <br />water in each well was determined. Each of the alluvial wells were purged using a new <br />disposable poly bailer. A minimum of three casing volumes was purged from each well <br />prior to sampling. <br />All groundwater samples were submitted to Evergreen Analytical Laboratory, located in <br />Wheat Ridge Colorado, for analysis. Evergreen subcontracted analyses for radiochemical <br />parameters to Hazen Research, located in Golden, Colorado. <br />During the second quarter 2008, GCC installed an additional shallow groundwater <br />monitoring well at a location between the mine plant operations and the St. Charles <br />River. The new well location was selected with input for the Division of Reclamation, <br />Mining, and Safety (DRMS). Groundwater was not encountered in the shallow aquifer at <br />the time the well was installed, and no sample was collected. <br />RESULTS AND DISCUSSION <br />Results of the groundwater sampling are provided in Table 1. Analytical results provided <br />by the contract laboratories are presented in Appendix A in PDF format. <br />1