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Page 2 March 20,2020 <br /> wells were submitted to DRMS on December 18, 2018. The groundwater study presented in the Report shows the <br /> following key findings: <br /> • The Top Rim Sandstone is of very low permeability as indicated by slug test results and slow well recovery <br /> after pumping;the Top Rim is an aquitard. <br /> • The hydraulic gradient in the vicinity of the SMC and the Dolores River is likely very small, and almost flat, <br /> indicating near stagnant conditions in groundwater movement. <br /> • Groundwater velocities are estimated to be very low,of the order of 0.019 feet per day or lower. <br /> • If groundwater flow were to occur from the SMC to the Dolores River, the travel time is conservatively <br /> estimated to be 2,740 years. <br /> • There is no existing use of Salt Wash groundwater in the region;potential future use is unlikely. <br /> • Water levels in well MW-SUN2 are influenced by other water-bearing units at higher elevations in the well. <br /> • The local groundwater gradient in the SMC area is toward the workings at this time. <br /> • Water quality data show increasing salinity and degrading water quality in the interpreted downgradient <br /> direction,i.e.from MW-SUN3 to MW-SUN1. <br /> • Constituent concentrations in well MW-SUN1 are the result of thousands of years of residence time of the <br /> groundwater in the Top Rim unit. <br /> • Water levels in wells MW-SUN1,MW-SUN3 and the flooded mine workings are rising and are likely gradually <br /> attaining the local potentiometric head for the Top Rim unit. <br /> These findings support a proposed groundwater monitoring program where semi-annual water quality sampling is <br /> implemented at the SMC concurrent with water level monitoring of the wells and mine workings through a period where <br /> water levels stabilize. It is also proposed that annual monitoring will commence once groundwater elevations become <br /> somewhat stable during mining operations.Monitoring during post-mining operations will be decided at that time. I am <br /> available by phone or in person,as appropriate,to discuss the Report.You may contact me at(970)242-0170. <br /> Sincerely, <br /> Bruce D.Smith <br /> Principal Hydrogeologist <br /> WESTERN WATER&LAND,INC. <br /> cc: James Blair,USBLM Tres Rios Field Office <br /> George Glasier,PRM <br /> Mike Rutter,PRM <br /> Frank Filas,Filas Engineering <br /> enclosure <br /> LWest032020.doc <br />