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Whirlwind Mine Groundwater Characterization Report <br /> Generally, this section discusses water chemistry types based on known or perceived source <br /> hydrostratigraphic units, e.g., water samples collected from the Brushy Basin are considered <br /> Brush Basin sources. This section also discusses the general concentrations of dissolved <br /> constituents from water sources of the Whirlwind Mine project area that have designated <br /> Colorado water quality standards under CDPHE Water Quality Control Division (WQCD) <br /> Regulation 41 —The Basic Standards for Groundwater(5 CCR 1002-41). Table 7 presents <br /> water chemistry data for constituents of concern that may exceed state water quality standards <br /> for the key water sources in the vicinity of the Whirlwind Mine. Appendix A presents a summary <br /> of all laboratory analytical results for the water sources monitored at and in the vicinity of the <br /> Whirlwind Mine. <br /> The Colorado groundwater quality standard for radium applies to the combined activity of <br /> radium-226 and radium-228, a standard of 5 picocuries per liter(pCi/L). Laboratory analysis <br /> may report radium-226 and radium-228 separately, therefore if any one isotope exceeds <br /> 5 pCi/L, then the standard is exceeded. The uranium Colorado groundwater standard as a metal <br /> is a range (standard of 0.0168 to 0.030 milligrams per liter[mg/L]). The Colorado standard for <br /> gross alpha is 15 pCi/L. However, it is not known if these results were corrected for alpha <br /> originating from radon and uranium. Most of the gross alpha count in the Whirlwind Mine <br /> monitored sources is attributable to uranium (EFR, 2022). Vanadium has a Colorado agricultural <br /> standard of 0.1 mg/L. <br /> 5.2.1 Burro Canyon Chemistry <br /> The chemistry of samples collected at DP Spring, Dolores Point well, and the two Cherokee <br /> wells are very similar and are considered Burro Canyon water sources. It is known that the <br /> Dolores Point well is completed in the Burro Canyon, and DP Spring emanates near the base of <br /> the formation. As shown in Figure 8, the common ion chemistry plots for these sources plot in a <br /> close group near the left corner of the plot, indicating a calcium-bicarbonate water type. This <br /> type of chemistry is more common in source rock such as dolomites and limestones but may be <br /> present in sandstones with calcium carbonate cement. Also, it was noted by EFR that a minor <br /> water-bearing zone was present in a five-foot thick limestone bed at the 75-to 80-foot depth in <br /> the Dolores Point well. <br /> Western Water& Land, Inc. 27 <br />