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SUNDAY MINE COMPLEX-HYDROGEOLOGIC REPORT <br /> of a sodium-potassium sulfate type, MW-SUN2 groundwater is of a sodium-potassium <br /> bicarbonate type, and MW-SUN3 groundwater is of sodium-potassium bicarbonate-sulfate type. <br /> For a conceptual groundwater flow path in the downdip direction within the Top Rim Sandstone, <br /> the water chemistry results support the common occurrence of increasing salinity in the <br /> downgradient direction. Water quality in well MW-SUN3, at the upgradient location, has the <br /> lowest TDS concentrations, whereas well MW-SUN1, at the downgradient location has the <br /> highest TDS concentrations. The Piper Plots indicate an evolution in water chemistry along the <br /> flow path from a more bicarbonate water type to a sulfate water type. Chloride does not attain <br /> significant concentrations to affect water type. <br /> Common ion concentrations of samples collected from mine underground locations fall within <br /> the chemical trends of the monitoring well data. These samples are expected to show <br /> anomalous concentrations because they were collected from the mineralized zone of the Top <br /> Rim aquitard; mining of the mineralized rock may also generate fine materials that when <br /> exposed to groundwater leach minerals more readily. The exposure to oxygen may also effect <br /> leached concentrations of chemical constituents in the mine and vent shaft samples. <br /> Total alkalinity concentrations and the prevalence of high proportions of sodium within the <br /> groundwater of the three monitoring wells are similar, but well MW-SUN1 has a distinctly high <br /> proportion and concentration of sulfate. The source of the sulfate is of some interest. The <br /> concern as to whether the foam additive used during drilling may have influenced the well water <br /> chemistry was considered. The drilling additive used at well MW-SUN1 and presumably at well <br /> MW-SUN2 was a product called Platinum Foam Plus. This product is National Sanitation <br /> Foundation (NSF) and ANSI 60 certified. A key compound in this product is sodium (C14-C16) <br /> olefin sulfonate, which is a surfactant also used in commercial hair shampoos. No information <br /> was found that demonstrated that this sulfur-containing compound would degrade to sulfate. <br /> The presence of sodium in this compound could possibly affect sodium concentrations in the <br /> well water as well. However, sodium is prevalent in all the groundwater sampled in the Salt <br /> Wash Member. In addition, the initial and follow-up well development conducted at well MW- <br /> SUN1 and the multiple sampling events that have occurred over time should have greatly <br /> diminished any remaining drilling chemicals. <br /> Sources of sulfate in natural groundwater systems are usually related to the presence of pyrite <br /> (FeS2), gypsum (CaSO4.2H20), and anhydrite (CaSO4). Sources of sodium may include halite <br /> (NaCl) and nahcolite (NaHCO3). The influence of mineral dissolution and precipitation of <br /> Western Water& Land, Inc. 46 <br />