2018-05-30_PERMIT FILE - M2018028

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Environmental Effects Proposed Action Direct and Indirect Impacts: The Proposed Action would essentially remove the topsoil (approximately 12 inches)from 0.6 acres and process the material underneath by hydraulically sorting the gold out of the alluvium. This process totally destroys the soil structure and disrupts the soil organisms and processes. Due to the nature of the action it is imperative that both interim reclamation and final reclamation be done properly in order to return the site to its pre- disturbed condition. In order to preserve the functionality of the soils,the topsoil needs to be separated and stockpiled until it is used for reclamation. Then at the time of reclamation the soil would need to be placed back in the order it was removed,thereby keeping the original A, B, and C horizons. In order to do this,more than one soil stockpile would be needed, i.e. one for the A and one for the B horizons. Due to the sorting process that the C horizon would undergo,replicating the same manner of sorting in this horizon would be extremely difficult. In the C horizon, the fine material would likely be difficult to recover in the same manner as the larger material. This could leave voids and a different density of material under the topsoil resulting in changed water holding capacity and root growth medium. Overall, the Proposed Action would impact up to 0.6 acres of soils until reclamation is considered complete. In the long term, after reclamation is considered complete, the soils would be essentially similar to their current condition. Protective/Mitigation Measures: • Performance expectations for the established vegetation will be based on an optimum ground cover of 40%for the native seed mixture suggested in section 3.3.3 Vegetation(not including annuals),understanding that this is an ideal situation given that current vegetation conditions are not meeting these specifications. In addition, successful reclamation will include stable soil conditions at natural background erosional rates. • On any slopes that are greater than 3:1, excelsior matting is suggested to be installed following the manufacturer's installation instructions to reduce erosion rates on disturbed soils. • In order to maintain as much topsoil as possible and in addition to the upgradient Stormwater controls to be installed as described in the Plan of Operations modification, it is suggested that downhill portions of the soil stockpiles have controls installed also, such as straw wattles or silt fencing to prevent soil from leaving the disturbed area. Cumulative Impacts: At the larger watershed scale along the Arkansas River,the Proposed Action would add an additional 0.6 acres of disturbance spread out over several years. Along the river there are many other existing soil disturbances such as highways,recreation sites, and home sites. The addition of this disturbance with mitigation would not appreciably add to the overall area. No Action Alternative Direct and Indirect Impacts: