2023-07-19_REVISION - M2021052 (12)

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Rifle Gravel Pit#1 July 2023 6.1.1.1 Materials Handling Scott will set forth the following materials handling measures: • All grading will be done in a manner to control erosion and siltation of the Affected Lands, and to protect areas outside the Affected Lands from sedimentation derived from the Affected Lands. • Reclamation of the perimeter berm will occur during Phase 1. Reclamation of the greenbelt area will occur during Phase 3, in concert with mining and the expansion of the pit. Final Reclamation will occur during Phase 4. • All refuse and acid-forming or toxin-producing materials, if found, will be handled and disposed of in a manner that will control unsightliness and protect the pond from pollution. No such materials are expected to be encountered. • Any drill or auger holes that are part of the mining operation will be plugged with non- combustible material. There will not be any adits nor shafts at this location. • The maximum slopes are depicted on Figure 11, Exhibit C6. This detail depicts a 5:1 slope for the upper portion of the reclaimed pond and was informed by the CPW staff concern for avoiding entrapment of wildlife in the pond, as well as Garfield County LUC standards (LUC Section 7-1002.H.2). • No inert structural fill generated outside of the approved permit area will be backfilled into the mining pit. • All mined material that will be disposed of within the Affected Lands will be handled in such a manner so as to prevent any unauthorized release of pollutants to the surface drainage system. • No unauthorized release of pollutants to groundwater shall occur from any materials mined, handled or disposed of within the Affected Lands. 6.1.1.2 Topsoiling The extent(area and volume) of the topsoil and overburden storage/stockpile areas was calculated assuming that all overburden material and topsoil that are not used for the construction and reclamation of the perimeter berms will be stockpiled on site. The excess overburden (30,423 cubic yards [CY])will be temporarily stored 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. 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 location of the stockpile areas is depicted on Figure 9, Exhibit C4 and located to provide physical separation between the stockpiles, mining activity, and any wetland or tailwater channel buffer areas and intended to prevent inadvertent sediment discharges off-site. Earthwork volume calculations are provided in Figure 14, Exhibit E1. The following management practices and standards will be applied to the stockpiles: 37