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Rifle '-Iravel Pit #1 august 2021 <br /> Although not included as part of the Permitted (Affected)Area, Scott Contracting, Inc. <br /> obtained a Colorado Department of Transportation (CDOT) Access Permit (Permit No. <br /> 320024, Attachment B) to improve CR 346 with a hard surface from mile post 94.50 to <br /> 95.14 at the access to Rifle Pit#1. <br /> Equipment <br /> This phase will use conventional earth moving equipment to grade, remove vegetation and <br /> stockpile topsoil, but not limited to a bulldozer, track-hoe, and a 35-ton haul truck. <br /> Dewatering pumps will also be used at each well. <br /> See Exhibit D1, Figure 10 and Exhibit D3, Figure 12 for a cross-section of the typical mine <br /> strata and additional information regarding the topsoil and overburden handling locations. <br /> Note overburden materials across the site vary. The boring holes indicate the overburden <br /> depth can vary from 5.5 feet to 6 feet. Attachment C includes the typical cross-sections at <br /> the boring holes. <br /> 5.2.1.2 Water Diversions and Impoundments <br /> Scott Contracting, Inc. will install a low-water crossing at the existing tailwater culvert <br /> crossing or collect the water in a pipe. Scott Contracting, Inc. will not disturb the tailwater <br /> channel in its existing location and implement BMPs to prevent mining operations from <br /> discharging into or comingling with these waters. <br /> 6.2.1.3 Water Handling, Dewatering, and Permits <br /> Stormwater Management <br /> Scott Contracting, Inc. will apply for coverage under Permit No. COR400000, Colorado <br /> Discharge Permit System (CDPS) General Permit (for) Stormwater Discharges Associated <br /> with Construction Activity at least 10 days prior to the commencement of construction <br /> activities disturbing greater than or equal to 1 acre. This permit has requirements that <br /> address water quality and stormwater management, including monitoring and reporting, and <br /> the development and implementation of a Stormwater Management Plan (SWMP). <br /> Scott Contracting, Inc. will not disturb the tailwater channel in its existing location and <br /> implement BMPs to prevent mining operations and will install a low-water crossing at the <br /> existing tailwater channel crossing or collect the channel in a pipe. See Attachment A for a <br /> copy of the erosion control BMPs. <br /> Pit Mining—Dewatering Wells <br /> Scott Contracting, Inc. will support the mining dewatering needs using 3 wells (plus <br /> temporary drains and pumps to capture incidental inflows). The rate of groundwater <br /> discharge (pumping) associated with dewatering is expected to approach about 7 cfs. Mr. <br /> Bill Hahn (Hahn Water Resources, LLC) predicted the anticipated dewatering operations <br /> (through modeling); however, this is an estimate based upon borings and groundwater level <br /> data. Mr. Hahn presented one possible dewatering configuration that might be employed for <br /> dewatering associated with the initial stages of mining. Figure 14Figure 14 shows the <br /> estimated drawdown following one-year of dewatering using 3 wells in the vicinity of the <br /> Stage 1 and Stage 2 mining limits and the approximate locations of the dewatering wells. <br /> 19 <br />