2016-08-01_PERMIT FILE - C1981010A (14)

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are designed and located to prevent an excessive buildup of road water runoff and 16 yet divert the runoff at locations that minimize dumping channelized flow from the road onto slopes that are not geomorphically adapted to channelized flow. in conjunction with this endeavor, culverts or other suitable structures are provided to intercept flow of runoff before reaching a switchback. Culverts used for road water runoff only are placed at an angle of 30° or less to the road downgrade when practicable. Riprap or other suitable material may be used to protect areas where erosion is anticipated or demonstrated. Cut-outs through the road berm may also protected with riprap or culvert pipe. Additionally, Trapper may riprap the culvert out- fall or use other suitable material where necessary to prevent erosion. Culvert inlets have not been subject to erosion due to road base material around the inlet. Therefore, riprap or headwall protection is not necessary. Culvert entrances are protected where necessary with two fence posts which mark the end and sides of the culvert. This system provides adequate identification of cul- verts during sediment trap cleaning. • Maintenance of Ditches and Culverts: • Culverts and ditches are maintained on a routine and regular basis. Road ditches are cleaned regularly with a road grader or similar equipment. Culverts are inspected regularly and cleaned as necessary. Debris in trash racks and culverts is removed as it occurs to prevent interference with the drainage. The Trapper Mine's Environmental Quality Department inspects the road drainage system and identifies any problem areas on a regular basis. The problem areas are then corrected. 3.7.2.4 Surfacing Haulroads at the Trapper Mine are surfaced with various materials such as local pit run gravel, scoria and occasionally spoil. Asphalt and other types of sur- facing may be used in the future. All the materials that are presently 3-169 REVISED FEB) 13 '87