2023-07-19_REVISION - M2021052 (16)

Home Browse Search

RECEIVED Rifle Gravel Pit#1 July 2023 II II 1 �M91 Colorado Division of Reclamation, 5.0 Exhibit D — Mining Plan Mining and Saftey Rule 6.4.4 outlines the requirements for Exhibit D as described below. This section is organized to recognize the mining methods, earthmoving, and size of the areas associated with the unique phases and stages of mining. 6.1 Project Location and Information The proposed Rifle Gravel Pit#1 parcel located along CR 346 (1-70 North Frontage Road) which begins at Mamm Creek Road on the west and ends in a cul-de-sac approximately 2.1 miles east of Mamm Creek Road. Approximately 0.5 miles east of Mamm Creek Road, CR 346 turns from a paved 2-lane roadway to a gravel two-lane roadway and remains gravel to the cul-de-sac at its east terminus. The proposed access driveway to the site is located 1.1 miles east of Mamm Creek Road on the north side of CR 346 (Figure 1, Exhibit A and Figure 2, Exhibit B). The address for the property is 5127 N CR 346, Rifle, Colorado 81650. 6.2 Mine Facilities and Operation The proposed development would be a continuous wet mining operation (NOT intermittent) where the topsoil and mineral overburden would be removed and used to construct and revegetate the perimeter berm. The excess overburden (30,423 cubic yards [CY]) will be temporarily stored during Phase 1 and retained as mining progresses to provide fill in the instance mining ceases. This material will be sold as a secondary commodity, to allow for the expansion of mining during the 60% to the 100% mining stages during Phase 3. The excess topsoil (9,539 CY)will also be stored and stabilized with an upland seed mix. The topsoil (9,006 CY) will be sold as a secondary commodity during the 60%to 100% mining stages during Phase 3, to allow for mining expansion, except for the reclamation topsoil material. Approximately 533 CY of the excess topsoil will be needed to reclaim the greenbelt areas during final reclamation during Phase 3 and Phase 4. The underlying saturated alluvial gravels would be excavated in their saturated state. Excavation would be accomplished using a long-reach excavator located on the upper rim of the excavated pit. No dewatering nor groundwater pumping would occur with this proposed mining development, and the excavated pit would fill with groundwater to become a pond as mining progresses through the site. Figure 9, Exhibit C4 depicts the proposed mining operations at the Phase 1, Phase 2 and Phase 3 30% development stage. Figure 10, Exhibit C5 depicts the proposed mining operations at the Phase 3 60% development stage. Figure 11, Exhibit C6 depicts the mining conditions at Phase 3 100% development, i.e., final conditions. Please note that these sheets extracted from the drawing set in Attachment A and have callouts and leaders on the drawing that define specific features. These drawings are also part of other permit applications that require features to be called out differently than DRMS yet serve multiple purposes across permitting agencies. The mining phases are as follows: • Site development and grading (Phase 1) • Mining preparation (Phase 2) • Mining extraction and Greenbelt Reclamation (Phase 3) 21