2024-04-08_PERMIT FILE - M2024015

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Recommendations for monitoring of slope stability, including, conducting a visual inspection of the excavated slopes on a weekly basis for the duration of mining, conducting a visual inspection after a major precipitation event that has saturated the ground using the same procedures, contacting qualified personnel to evaluate and recommend remediation work to stabilize the area in the event a visual inspection detects signs of potential slope failure, and if no visible signs of slope failure are detected during mining, reducing visual inspections to once every six months after mining completion, or after every major precipitation event. During reclamation activities, inlet and outlet facilities for the reservoir will be designed and installed once the operational criteria of the proposed reservoir have been identified by an end user. Reclamation Measures/Materials Handling Backfilling will be done to provide stabilized shorelines around the reservoir and to minimize erosion. The backfill material will consist of gravel and topsoil. There will not be known toxic or hazardous materials in the backfill material. Additionally, it is not likely that acid forming or toxic materials will be encountered during mining. The mining will not leave high walls on the property. In addition, there will be no auger holes, excavations, or shafts left on the property. The auger holes for the gravel investigation were backfilled with native gravel and soil cuttings from the drilling. The auger holes that were not backfilled were the four monitor wells that were constructed and permitted as permanent monitoring wells to monitor groundwater at the north, east, west, and south sides of the permit boundary. Monitor wells will remain on the property so the end user may continue to monitor levels of the groundwater elevations. Topsoil will be placed to finalize the grading such that seeding can occur. The topsoil will be placed at all disturbed areas and on the mining slope to an elevation matching the expected reservoir water level. Topsoilinq Approximately the top twelve inches of soil on the property is classified as topsoil. This layer includes the root zone of grasses and crops, which will be stripped and stockpiled separately. Topsoil will be re-handled as little as possible and a Technical Revision will be submitted prior to re-locating topsoil stockpiles. By using concurrent reclamation techniques, the topsoil is not expected to remain in stockpiles for more than one to five years. If the stockpile remains more than one growing season, it will be seeded with a fast-growing vegetative cover to prevent erosion. All topsoil will be retained on-site to reclaim the reservoir shoreline, and other areas disturbed by mining activities. Where required, topsoil will be replaced to a depth of twelve inches. Prior to placing topsoil uneven areas and low spots will be graded to subgrade elevation, in addition debris, roots, branches, stones, in excess of 2 inch in size will be removed. Scarify surface to depth of 8 inches where topsoil is to be placed for a roughened condition to assist in eliminating erosion. Scarify/cultivate in areas where equipment used for hauling and spreading topsoil has compacted subsoil. Place topsoil during dry weather and on dry unfrozen subgrade. Remove vegetable matter and foreign non-organic material from topsoil while spreading. Grade topsoil to eliminate rough, low or soft areas. Revegetation As mining operations are completed, areas for reclamation will be graded and shaped for revegetation. Runoff or excess water from adjacent areas will not be allowed to flow over slopes 111 JsT Consulting,Inc. Central Colorado Water Conservancy District I 1111 Sweet Valley Pit DRMS 112 Permit Application