2018-07-09_GENERAL DOCUMENTS - C1981019

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Proposed Decision and Findings of Compliance July 2018 Permit Renewal No. 7 P a g e | 55 Lower Taylor Creek, a tributary to Wilson Creek, contains small areas with alluvial deposits, but does not contain enough water to provide for sub-irrigation of croplands. Taylor Creek, which will be mined in its upper reaches, is therefore not considered an alluvial valley floor. The West Fork of Good Spring Creek was investigated in association with PR-02, and was determined not to be an alluvial valley floor due to the restricted width of the alluvial deposit along most of the reach, and the absence of sub-irrigated or flood irrigated agricultural activity (current or historic). Other Stream Valleys in the General Area Various other stream valleys with unconsolidated alluvial deposits in the mine vicinity may meet alluvial valley floor criteria, but have not been evaluated as a part of this review because th ey are located outside the proposed permit boundary or there is no proposed mine disturbance within their watersheds. These valleys include the East and West Forks of Wilson Creek, which are located upstream of any proposed mining, the East Fork of Good Spring Creek, located upstream of any proposed mining, and James Creek, located upstream of any proposed mining. B. Primary Impacts None of the four designated alluvial valley floors are within the area to be mined; therefore, mining operations will not cause direct disturbance to any alluvial valley floors. Any mining impact that might occur will be indirect in nature. C. Secondary Impacts It that the areas to be mined presently contribute relatively little water to alluvial valley floors. Any degraded water that might reach an alluvial valley floor would be diluted by other sources. In addition, alluvial valley floors are protected by both stream buffer zones and treatment of runoff from disturbed areas by sediment ponds. The Gossard Loadout is located near the confluence of Wilson and Taylor Creeks and the alluvial valley floor associated with Wilson Creek. There is a slight potential for waters of degraded quality to reach alluvial materials near the loadout. An alluvial well located near the loadout is monitoring this situation. Runoff from the surrounding areas above the loadout are diverted around the disturbance and waters from the disturbance itself are treated in sediment ponds and must meet CDPS standards before being released. Waters leaching salts from reclaimed spoils may eventually reach Taylor, Wilson and Good Spring Creeks. It is believed that these spoil waters will still meet CDPS standards and will not contribute salts in levels that would warrant changes in mining and reclamation plans. This situation will be monitored through alluvial wells located on Wilson Creek (near the Gossard Loadout) and on Good Spring Creek and West Fork Good Spring Creek, both above and below mining disturbances.