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<br />_z;_ <br /> <br />3J and 2.07. <br />and Cumulative ?mva cts Assessment - <br />The Munger Canyon operation will potentially affect surface water and ground <br />water. Cumulative impacts to the hydrologically adjacent area would result <br />from the Munger Canyon operation impacts combined with the hydrologic impacts <br />produced by other operations (namely the Dorchester Fruita Mines and the <br />~tcCZane Canyon Mine) within the same hydrologic system(s). An assessment of <br />these impacts is presented here. <br />Probable Hydrologic Consequences <br />The anticipated impacts of the Munger Canyon operation on *he quality and quantity <br />of ground water and surface water in the area are rtinimal. This is due mainly <br />to the small area of surface disturbance related to the mine, as we 11 as the <br />characteristics of the ground water environment. <br />The disturbance related to the operation will encompass approximately 35 acres <br />in Munger Canyon. Compared to the total drainage area in Plunger Canyon (5085 <br />acres), approximately seven-tenths of a percent of the Munger Canyon drainage <br />will be impacted by the operation. Although increases in concentrations of <br />total dissolved solids (TD51 and total suspended solids (TSS) are expected to <br />result from the disturbance, the areal comparison indicates that the significance <br />of the increases in TAS would be diminished due to dilution, and TSS will be <br />controlled by sediment ponds. Furthermore, once the rvnoff From the ~~tunger <br />watershed reaches the East Salt Creek YaZ1ey, the _moact would be diminished <br />further. The disturbance due to the ocera ti on only accounts for five- <br />. hundredths of a percent of the total drainage area of cast Salt Creek above <br />the confluence with Munger Cannon (67,228 acres). <br />There is a potential for the operation to deplete the quantity of flow in :danger <br />Creek. :his potential is slight. water stored in impoundments will always be <br />less than t:+o acre-feet per structure and there are onlu two structures. The <br />ponds will also be dewatered to the required storage capacity following any ma;'or <br />storm event. Additionally, precipitation in the area is so Iow (8.8 inches <br />annually) that it is expected that very little to no water will be stored in <br />either impoundment most of the time. <br />Very little ground water :+as encountered during exploratory drilling in and <br />around the permit area. Salt Creek :fining Company does not expect to .have to <br />discharge mine :+a ter as a r=salt of consistent inflow into the mine. Some <br />depletion of surface water by infiltration into the ,nine :+orkinos through natural <br />and .nine-induced fractures may occur. The amount of depletion would be minor <br />due to the steep local topography and low precipitation. The slope varies from <br />?~;:lh to ov:lh, and the precipitation is d.8 lnches per near. <br />The veru Zow amount of surface :+a ter runof_` that does occur is concentrated i^ <br />periods or snowmen and thunderstorm =vents.These events produce short duration, <br />nigh volume runoffs wni ch, :+hen coupled with the steep topography, area by <br />favors sur_'ace :+a ter runof.` over t.`.e infiltration r_' :+ate_^. <br />• <br />