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Lorenrira Cam•an Mine -Groundwater Technn:a! Reuort <br />• Ground Water Quality <br />Overview <br />Ground water quality in the area has been characterized in literature and by site specific studies. <br />Review of the study by Howard indicates general quality parameters for the Raton and Poison <br />Canyon Formations. These parameters indicate a highly mineralized ground water with specific <br />conductances in the Poison Canyon and Raton Formations of 1 ]99 and 1884 µmhos/cm, <br />respectively. From the samples collected within the formations comprising the Colorado Raton <br />Basin, the mean TDS value was 1026 mg/l. Within the samples obtained by Howard, pH, calcium <br />(Ca), sodium (Na), potassium (K), chloride (CI), sulfate (50,="), nitrate (NO; as N), fluoride (F), <br />total iron (Fe), and manganese (Mn) were elevated within some samples. Statistical parameters <br />from this study are present on Table GW-5. <br />In addition to collection of ground water samples and subsequent analyses of these samples, <br />Howard also determined water types for the major formations in the Raton Basin. These <br />deterrninations were made based upon analyses of the cation and anion percentages on trilinear <br />diagrams (Piper, 1942) (Figure GW-2). Following the identification of the chemical characteristic <br />of each sampling point a map was constructed of the dominant water types in the Raton Basin. <br />• This map is presented as Figure GW-3. Examination of the map indicates the dominant water <br />type in the area of the proposed Lorencito Mine to be of a sodium bicarbonate (NaHCOr) type. <br />Howard further plotted samples from each formation on separate trilinear diagrams to determine <br />the water types from the individual formations. Water from the Poison Canyon Formation is <br />characterized as a calcium bicarbonate (CaHCO~) type, and waters from the Raton/Vermejo <br />Formations are classified as a NaHCO~ type (Figures GW-4 and GW-5). <br />Site Specific Results <br />lndmills <br />Windmills in the site area were surveyed in August 1996. Each windmill was surveyed for depth <br />to water (if possible), temperature, pH, specific conductance, and dissolved oxygen. Several of <br />the windmills were either non-operational, or were inaccessible. Table GW-6 summarizes the <br />data collected from the wells, and Map 2.04.7-1 illustrates the location of the windmills. <br />Conductivity data from these windmill sites indicates a fairly high degree of mineralization. <br />Comparison of the dissolved oxygen readings and pH values from WMBC2 and WMCWC2 <br />indicate the water in the stock tank may not be representative of the water pumped from the wells. <br />Several of the wells are set in the alluvium; however, depths of many of the wells would indicate <br />that these wells are not set within the alluvium, but within more competent rock. <br />C1 <br />Groundwater 37SDecember 9, 1996 13 <br />