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Mr. Tom Schreiner, Division of Minerals and Geology ~~ March 23, 2005 Page4 crvir aES~uRCes,uc before exposing or pumping any groundwater. The approximate evaporative and operational losses were estimated using information from the miner and standard engineering practices. The applicant will lease reuseable effluent or some other source of replacement water to offset mining depletions at the site. See Comment 18 for the appropriate Tables. 6.4.7 EXHIBITG-Waterln/onnation 7. The existing water features on the Existing Conditions Map, 2 of 7 are difficult to discern. fn conformance with Rule 6.4.7(2)(a), please provide a separate "Water Features Map" that clearly shows the locations of a!! surface water and groundwater features in the affected land and surrounding area that may potentially be affected by the proposed mining operation. Such map should include the location of al! springs, wetlands, stock ponds, irrigation canals, Jateral irrigation ditches, registered domestic wells, and registered irrigation wells. Please note that the potential exists for adverse impacts to registered groundwater users in excess of 600 feet from the proposed excavation(s). Also, registered wells within the affected land and surrounding area should be identified as to ownership, well type and size, well pumping capacity, well depth, and volume of water assured by the owner's water right. Please respond. Refer to the attached Well Location and Hydrologic Features Map. This map includes wells and approximate locations of surrounding water features. 8. In conformance with Rule 6.4.7/2)(b), please clarify the aquifer characteristics of the Broadway alluvium to be affected by the proposed mining and reclamation operation. Specifically, describe the direction of groundwater movement in this shallow alluvial aquifer in and surrounding the area to 6e excavated; the saturated thickness, hydraulic conductivity, transmissivity, effective radius, and storage coeKcient of the aquifer in the area of excavation; whether the aquifer is confined a unconfined; any interaction between surface and groundwater throughout the year; the quality of water produced by registered wells in the affected land and surrounding area; the natural elevation of groundwater in the affected land and surrounding areas; and the range of depth for groundwater in the affected land and surrounding area throughout the year; and the expected depth of groundwater in the affected land and surrounding area during the peak of irrigation season or other such time when the demand for groundwater resources by a variety of domestic water users and/or irrigation water users in the surrounding area is at a maximum. Please respond. The requested information was discussed in the Groundwater Model Report, however we will restate here. The groundwater movement {gradient) is approximately north to northwest towards the South Platte River. The saturated thickness ranges from 20 to 25 feet, the hydraulic conductivity per a pump test performed in September of 2004 {see Appendix A of the groundwater model) is 165 feet per day and a storage coefficient of 0.2 was applied per general hydrologic practices. The transmissivity is defined as the hydraulic conductivity times the saturated thickness of the aquifer as presented in the Section 3.5 and Section 3.9 of the Groundwater Model. The aquifer in question is an unconfined aquifer bounded by an impermeable claystone floor and a permeable overburden surface as discussed in Section 2.1. The aquifer receives recharge from precipitation and receives irrigation recharge for approximately 5 to 6 months. No water quality sampling has been performed to date but a plan is being produced. The natural elevation of the groundwater is approximately 20 to 25 feet below existing ground surface and the average site elevation is 4940 feet above mean sea level, therefore the average site groundwater elevation is 4915 feet above