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<br />-~- <br />• Probable Hydrologic Consequences <br /> <br />The anticipated impacts of the Munger Canyon operation on the quality and <br />quantity of groundwater and surface water in the area are minimal. This is <br />due mainly to the small area of surface disturbance related to the mine as <br />well as the characteristics of the groundwater environment. <br />Very Title groundwater was encountered during exploratory drilling in and <br />around the permit area. SCMC does not expect to have to discharge mine water <br />as a result of consistent inflow into the mine. No wells or springs were <br />identified in Munger Canyon, and no groundwater rights have been adjudicated <br />within a three mile radius of the Munger Canyon Mine. Due to lack of major <br />aquifers in the proposed permit a-ea, the chances for the diminution of the <br />quality and quantity of groundwater is very slight. <br />The very low amount of surface water runoff is concentrated in periods of <br />snowmelt and thunderstorm events. These events produce short duration, high <br />volume runoffs whicfi, when coupled with the steep topography, greatly favors <br />surface water runoff over the infiltration of water. Some depletion of <br />surface water by infiltration into the mine workings through natural and mine <br />induced fractures may occur. The amount of depletion would be minor due to <br />the steep local topography (slopes varying from 2v:lh to 6v:lh) and low <br />precipitation (8.8 inches per year). <br />There is a slight potential for the operation to deplete the quantity of flow <br />• in Munger Creek. Water stored in the two impoundments will always be less <br />than two acre-feet per structure. The ponds will also be dewatered to the <br />required storage capacity following any major storm event. Additionally, <br />precipitation in the area is so low (8.8 inches annually) that it is expected <br />that very little or no water will be stored in either impoundments most of the <br />time. <br />The disturbance related to the operation will encompass approximately 35 acres <br />in Munger Canyon. Compared to the total drainage area in Munger Canyon (5085 <br />acres) approximately 0.1% of the Munger Canyon drainage will be impacted by <br />the operation. Increases in concentrations of total dissolved solids (TOS) <br />and total suspended solids (TSS) are expected to result from the operation. <br />The areal comparison indicates that the significance of the increases in TDS <br />would be diminished due to dilution; TSS will be controlled by sediment ponds. <br />Furthermore, once the runoff from the Munger watershed reaches the East Salt <br />Creek Valley, the impact would be further diminished. The disturbance due to <br />the operation accounts for only 0.05% of a percent of the total drainage area <br />of East Salt CReek above the confluence with Munger Canyon (67,228 acres). <br /> <br />