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W W RESOURCE <br />L./ HYDROGEOLOGIC <br />V SERVICES <br />BEDROCK GROUNDWATER <br />In December 2015, a seep was discovered in the gully overlying the King II Mine lease, at the base of <br />the Cliff House Sandstone. The location of the seep (Seep -1) is shown in Figure 1. Its location almost <br />certainly indicates it is sourced by the sandstone, which overlies the coal formation (Menefee siltstone, <br />shale and coal). This is the only substantial seep known in the King II area, and although it has a flow <br />less than a gallon per hour, it is subject to abundant wildlife use, and based on observed tracks and <br />animal hair is a wallow for deer, elk and bear. This seep has been sampled a total of five times for the <br />GCC S&S Baseline suite for full laboratory analysis and eleven times for the TR -26 approved field <br />parameter list, and remains on the GCC hydrologic monitoring location list. <br />Major ion composition of the seep water is shown in Figure 8. Given the wildlife traffic the water <br />analyses are bound to show a water quality imprinted by that wildlife use, and in fact in the summer <br />nitrate is reported on the order of 1 mg/L. <br />Seep -1 major ions are dominated by sulfate, likely derived from sandstone pyrite and contact with the <br />underlying Menefee formation. Bicarbonate is a small component because there is relatively little <br />carbonate cement in this barrier sand (deposited by beach and dunes invading the coal -forming <br />swamps). Concentrations of TDS and sulfate are both greater than the recommended standard for <br />stock use high for stock use (250 mg/L for sulfate). <br />Concentrations of nitrate and nitrite in Seep -1 were less than the drinking water standard of 10 mg/L. <br />Similar to the alluvial groundwater samples, iron and manganese were detected in Seep -1 samples. <br />The distributions (that is, the range of concentrations reported) of the concentrations of these two <br />metals are shown in Figures 5 and 6. Increased iron and manganese concentrations were reported in <br />September and December samples from Seep -1, on the order of 1 mg/L, where previously they were <br />not detected. These values could suggest some variation in flowpath of infiltrating water, however <br />additional monitoring is needed to confirm the apparent trend. All other trace metals (aluminum, <br />arsenic, cadmium, lead, mercury, molybdenum, selenium, uranium and zinc) were reported to be at <br />concentrations below drinking water standards. Concentrations of total organic carbon, an indicator <br />parameter of wastewater, disinfection or fertilizer impacts, were reported to be up to 6 mg/L in seep -1 <br />samples, which is a low -flow environment with abundant wildlife activity. <br />RECOMMENDATIONS <br />With comprehensive review of the expanded baseline parameter list results and increased frequency of <br />monitoring for the one-year period during 2016 for the existing compliance Hay Gulch Ditch location, <br />added Hay Gulch Ditch Upgradient location, alluvial wells and added Seep -1 location, no trace metals <br />or minor constituents to be significant with respect to water quality have been observed. This considers <br />drinking water standards, although naturally occurring major ion concentrations (specifically TDS, <br />sulfate) disqualify the alluvial aquifer as a primary drinking water source. Given the spatial variation in <br />water quality does not suggest any contamination of the alluvial aquifer by mining activity; it is proposed <br />GCC ENERGY, LLC <br />2016 ANNUAL HYDROLOGY REPORT <br />8 <br />