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Wattenberg Lakes Amendment, Exhibit E—Reclamation Plan May 2023 <br /> The mining and backfilling operations will create the rough topography for the Pond 1 reservoir shoreline. The <br /> backfilling will be done to provide stabilized shorelines around the reservoir and to minimize erosion.As shown in <br /> Exhibit F (Map F-1), backfilling of two existing unnamed ponded areas (from previous mining)will take place for <br /> final reclamation use for wetlands or cottonwood replacement; these areas are in the northwest and southeast <br /> corners of the permit area. Minor grading to reclamation grades will take place in all areas subject to reclamation. <br /> The backfill material will consist of native bedrock claystone and overburden and will be obtained from mining of <br /> Area 1 and Area 2 as well as fill material from previous mining that, for example, remains in the area immediately <br /> west of the mining area. Scrapers will be used to place the backfilled material. For Pond 1, using scrapers to layer <br /> the lifts at a maximum 3:1 slope ensures a stable configuration. <br /> Growth medium will be spread to a depth of approximately 6 inches over the surface of all areas to be <br /> revegetated as uplands or wetlands. <br /> 5.0 WATER STORAGE RESERVOIRS <br /> As noted above, the reclamation includes construction of the slurry wall and perimeter drain around the perimeter <br /> of the final footprint of Pond 1. Design specifications for the slurry walls and quality control procedures used <br /> during construction will ensure that the reservoirs meet State Engineer's Office (SEO) performance standards. <br /> Specific specifications and quality control procedures will be provided to the Division for review prior to <br /> construction of the slurry walls. <br /> The bottom of Pond 1 will coincide with the existing, relatively impermeable claystone bedrock. The slurry wall will <br /> also separate the pond from the surrounding alluvial aquifer. The slurry wall will be keyed into the bedrock <br /> material and extend upward through the entire length of the saturated alluvium. <br /> All reservoir slopes left by the mining operation will be reclaimed to at least 3H:1 V final grade; slopes above the <br /> post-mine high water level will be 3-1 and slopes below the post-mine high water level will be no steeper than 3:1. <br /> Reclamation of the side slopes will take place concurrent with mining of Area 1 and Area 2. Scrapers will be used <br /> to place bedrock claystone and overburden material along the reservoir perimeters to achieve the final grade. Final <br /> reclamation by capping with growth medium and re-vegetating above the expected reservoir water level will follow <br /> backfilling operations closely to minimize the amount of disturbance at any one time. <br /> During reclamation activities,inlet and outlet works for Pond 1 will be installed. The inlet works will be constructed to <br /> provide water from the Brighton Ditch along the west side of the site. Outlet works will be designed and <br /> constructed by the City of Westminster, the user of the reservoir for water storage. The design specifications and <br /> plans for the facilities will be provided to the Division prior to construction. <br /> 6.0 REPLACEMENT WETLAND AND RIPARIAN AREAS <br /> Specific areas identified in Exhibit F (Map F-1)will be reclaimed fbrwetland mitigation (36.7 acres)or cottonwood <br /> replacement(10.0 acres). Reclamation will begin after backfilling and minor grading and placement of growth <br /> media are completed in a reclamation area. Depending on groundwater elevations,the final surface elevation of <br /> the backfilled wetland mitigation areas may be below the existing and surrounding ground elevation. Any slopes <br /> remaining will be reclaimed to a minimum 3H:1 V grade. In the northwest part of the permit area, a 20-ft setback will <br /> be included from County Road 23'/2 to the top of the 4H:1V slope that is graded down to the wetland area. <br /> All areas disturbed by mining and site reclamation activities will be revegetated as appropriate with a seed mix, <br /> depending on the type of reclamation to be completed—wetland or upland. The planned seed mixes are <br /> presented below. <br /> 7.0 SURFACE WATER AND GROUNDWATER <br /> Overburden and mine materials will be inert and impacts to local surface water or groundwater quality are not <br /> anticipated to occur because of mining activities. Holcim will comply with all applicable Colorado water laws and all <br /> OTETRA TECH Page 3 1 6 <br />