Laserfiche WebLink
7. Groundwater <br /> Groundwater is located approximately 4 feet below the surface of the ground onsite. No wells <br /> are located within 600 feet of the proposed pit5. <br /> 7.1 . Groundwater Handling — Mining <br /> Mining activity will expose groundwater from the very beginning of operations. Dewatering of the <br /> pit will take place to bring the groundwater table below the operating floor. This allows <br /> equipment to safely and effectively mine the alluvial deposit. The pit pump will be active <br /> continuously during the mining season, which typically is mid-April to early-November, <br /> depending on weather. The pit pump will not run during flood events or when temperatures drop <br /> below freezing. <br /> Pit dewatering will intercept groundwater from the alluvial aquifer of the Colorado River that is <br /> onsite and route it back towards the river via discharge outfalls. This process is common among <br /> sand and gravel pits along the rivers and waterways of Colorado. The layout of the dewatering <br /> process can be found on Exhibit C maps and Map G-1, including the typical location of the pit <br /> pump, its typical installation, and dewatering path to the Colorado River. The pit pump will be a <br /> mobile pump with and accompanying diesel generator. This generator will have an onboard fuel <br /> tank with secondary containment. The pump and generator will move as needed to ensure a <br /> properly dewatered mining pit. The pump will be located two feet below the active pit floor. It will <br /> also be surrounded by a gravel filter. Water will then discharge from the dewatering pump via a <br /> pipe or drainage channels to the Colorado River to the north. This system of dewatering is <br /> proven to move the water out of the way of mining operations while trapping sediment on site. <br /> 7.2. Groundwater Handling — Reclamation <br /> Once mining and reclamation are completed on site, the pit pumping will cease. Permanent <br /> groundwater lakes will form as shown on Map F-1. <br /> 7.3. Groundwater Exposure and Water Rights <br /> Prior to any groundwater exposure onsite, an approved permanent augmentation plan <br /> will be in place with approval from the Colorado Division of Water Resources and the <br /> applicable water courts A technical revision will be supplied to the Division containing <br /> this approved augmentation plan prior to any groundwater exposure onsite. This plan for <br /> augmentation will ensure that all water depletions are replaced in the system in time, kind, and <br /> location. No mining will take place that exposes groundwater without this plan for augmentation. <br /> Phase 1 water for dust control will be purchased and used onsite in accordance with an <br /> approved Substitute Water Supply Plan. <br /> https://gis.colorado.gov/dnrviewer/Index.html?viewer=dwrwellpermit <br /> North Hangs <br /> December 2024 G-4 Lewicki&Associates <br />