Laserfiche WebLink
.y <br />YOABT MINE PERMIT APPLICATION C-94-082 <br />Response to Division of Minerals and Geology <br />1/20/95 Adequacy Letter <br />March 29, 1995 <br />Tab 13 - Facilities <br />3b. The designs for the diversion ditches in Tab 13 and the <br />reclaimed drainage in Tab 20 are based on vegetated channel <br />conditions. The Division is requesting a plan for temporary <br />stabilization of these structures until vegetation is <br />established. Seneca has provided, in various sections of the <br />permit application, temporary stabilization practices which <br />address the concerns of the Division. <br />In Tab 13, Page 3, Seneca states appropriate sediment control <br />measures for the constructed diversion ditches may include, <br />but not be limited to, maintenance of appropriate gradients, <br />channel linings, revegetation, roughness structures, and <br />detention basins. For reclaimed drainages on Page 10, Tab 7, <br />it states diversion ditches will be inspected for stability <br />according to the Rill and Gully Plan in Tab 22, Page 31. <br />Maintenance or monitoring that may be necessary as a result of <br />the inspections will be submitted to CDMG for review and, if <br />necessary, approval. The methods used to stabilize the <br />channels could include installation of approved check dams and <br />livestock ponds, erosion control matting, riprap, and straw <br />dikes. <br />Seneca personnel will analyze and decide which sediment <br />control measure or combination of measures listed above would <br />provide the best solution for stabilizing the channel should <br />a particular structure undergo erosion. we will then discuss <br />each site-specific problem with the Division for approval <br />prior to implementation of a particular stabilization plan. <br />Seneca has not provided an individual stabilization plan with <br />a particular drainage because what may work in one situation <br />may not in another. <br />59. Tab 17, Probable Hydrologic Consequences, has been revised and <br />new Attachments 17-2, 17-3, 17-4, and 17-5 added to <br />incorporate the projected life-of-mine impact analysis. <br />28 <br />