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Rifle Gravel Pit#1 June 2023 <br /> control, and aggregate dewatering. This perimeter berm will essentially provide a zero <br /> discharge of water, sediment-laden water, off-site. <br /> Scott will comply with the State Engineer Office's (SEO) rules and regulations regarding any <br /> water depletions that may occur during mining operations from water lost with mined <br /> aggregate and water used for dust suppression. A copy of the SEO permit applications to <br /> address depletions is included in Attachment C. <br /> Any agricultural return flows in the tailwater ditch, which are estimated at <2 cubic feet per <br /> second (cfs) during peak irrigation season, will be incorporated into the pond, mixed with the <br /> alluvial aquifer, and eventually migrate laterally through the permeable gravels into the <br /> larger Colorado River water table. Given the minimal flows in the ditch, the large size of the <br /> pond (estimated at 6 acres within one year), and the highly permeable nature of the gravel, <br /> the agricultural return flows will have a negligible effect on water levels in the pond. As <br /> excavation proceeds, the tailwater ditch will be subsumed into the expanding pond <br /> boundaries, until under final conditions the discharge point will be where the ditch enters the <br /> eastern boundary of the property. <br /> 5.2.4 Explosives <br /> Explosives will not be used during mining or reclamation of the property. <br /> 5.2.5 Schedule of Operations <br /> Hours of operation shall be Monday through Saturday 7 a.m. to 7 p.m. (Mountain Daylight <br /> Time, MDT)with no operations on Sunday. During winter months from 11/1 to 3/21 hours of <br /> operation shall be Monday through Saturday 7 a.m. to 5 p.m. (Mountain Standard Time, <br /> MST). <br /> Excavation and processing would occur approximately 8 months of the year depending on <br /> the occurrence of freezing temperatures (roughly April — November) and material sales <br /> would occur year-round. Total recoverable volume is estimated at approximately 292,810 <br /> CY of aggregate, which is expected to support operations for between three and five years. <br /> Approximately 3 to 5 employees will be on site during this phase of the mining operations. <br /> No nighttime activities are anticipated. Occasional equipment repair, or maintenance may <br /> be conducted at night, but lighting will be kept to a minimum and directed inward; the site <br /> will not have ambient lighting. <br /> 5.2.6 Existing or Proposed Roads <br /> No existing nor proposed roads will be used for the mining operation on-site. Scott will <br /> designate temporary travelways on the operating surface of the mine on a flexible and as- <br /> needed basis, to account for the changing layout of the mine as excavation proceeds. These <br /> travelways would consist of the native gravel materials exposed after removal of the <br /> overburden, supplemented with a surface of roadbase approximately 3" thick to control mud. <br /> The travelways on the working surface of the mine would not be permanently compacted, <br /> surfaced, or otherwise constructed. A portion of CR-346 (1-70 Frontage Road) will be <br /> improved as described in the pending new CDOT Access Permit (Attachment B) and used <br /> for access to and from the site. <br /> 5.2.7 Drainage and Runoff Conveyance <br /> Previous sections of this application describe the water handling activities for this proposed <br /> project. <br /> 30 <br />