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~ 826 21 '/~ Road <br />/ Grand Junction, CO 81505 <br />~ r`'~~ ~~ <br />C O R D I L L E RA N T: 970.263.7800 <br />F: 970.263.7456 <br />Exposure of groundwater will not occur during or after mining operations. <br />Stormwater will be released to the stream within 72-hours of impoundment, per conditions presented by <br />the Colorado Division of Water Resources. <br />8. Per Rule 6.3.3(1), please describe any sediment control and/or Stormwater runoff controls that will <br />be installed to prevent off-site impact. <br />A diversion ditch will be installed up-gradient of the proposed mining activities to prevent run-on to the <br />site. The flat staging area will be graveled with clean gravel from the materials mine on site. A temporary <br />water impoundment, measuring approximately 30 feet by 30 feet, will be installed down gradient of the <br />activity area to divert surface run-off from leaving the site. Any additional impoundments or alterations will <br />be assessed and addressed as mining progresses southward. Per the request of the Division of Water <br />Resources, water will be released to the stream within 72 hours of impoundment. The access road <br />bordedng the west boundary of the site has a bar ditch in place to divert surface run-on and run-off. <br />Another diversion ditch will be installed parallel to the access road bar ditch to ensure that water running <br />off of the pad surface passes through the impoundment for sediment settling before being released into <br />the access road bar ditch. Upon reclamation of the site, a third diversion ditch will be placed along the <br />base of the high wall to prevent water from running on to the flat pad surface. This site will be managed <br />according to the Stormwater Management Plan that has been created specifically for this site. The most <br />current version of the Stormwater Management Plan is located in Attachment 10. <br />9. Per Rule 6.3.3(1), please describe what measures will be taken to minimize disturbance to the <br />hydrologic balance, prevent off-site damage, and provide for a stable configuration for the <br />proposed future land use. <br />The top high wall will be maintained on a 1h to 1v slope during mining activities to prevent raveling. <br />Mining and surface activities will not extend to the up-gradient boundary of the permitted area; therefore, <br />a buffer will exist to further ensure that off-site impact does not occur. <br />A diversion ditch will be installed up-gradient of the proposed mining activities to prevent run-on to the <br />site. The flat staging area will be graveled with clean gravel from the materials mine on site. A temporary <br />water impoundment, measuring approximately 30 feet by 30 feet, will be installed down gradient of the <br />activity area to divert surface run-off from leaving the site. Any additional impoundments or alterations will <br />be assessed and addressed as mining progresses southward. Per the request of the Division of Water <br />Resources, water will be released to the stream within 72 hours of impoundment. The access road <br />bordedng the west boundary of the site has a bar ditch in place to divert surface run-on and run-off. <br />Another diversion ditch will be installed parallel to the access road bar ditch to ensure that water running <br />off of the pad surtace passes through the impoundment for sediment settling before being released into <br />the access road bar ditch. Upon reclamation of the site, a third diversion ditch will be placed along the <br />base of the high wall to prevent water from running on to the flat pad surtace. This site will be managed <br />according to the Stormwater Management Plan that has been created specifically for this site. The most <br />current version of the Stormwater Management Plan is attached. <br />The newly created slopes on this site will be reclaimed by bringing the slope to 1h to 1 v. A track hoe will <br />be used to create pockets in the soil. These pockets will provide a collection point for fine materials that <br />will produce a more favorable seed bed and will also increase the retention of water on the slopes. <br />Landscape materials salvaged during initial excavation of the site will be mechanically and/or hand- <br />placed to reinforce these pockets. Stockpiled salvaged topsoil will be distributed across the pockets at a <br />depth of approximately 2 to 6 inches. The size and frequency of the pockets will be dependent upon the <br />size and type of equipment used to create them. The pocketed slopes will be revegetated in the fall <br />immediately following the commencement of all mining activities, following the NRCS-recommended <br />revised seed mix found in the revised Exhibit 8. <br />Cordilleran Compliance Services, Inc. <br />Grand Junction, CO • Denver, CO • Casper, WY • Laramie, WY • Lander, WY <br />Environmental Consulting Engineers and Scientists <br />