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Mr. Al Amundson <br />Mr. Anthony J. Waldron <br />Environmental Protection Specialist <br />State of Colorado <br />Department of Natural Resources <br />Division of Minerals and Geology <br />July 8, 2002 <br />Page 5 <br />E. 6.4.7 EXHIBIT G — WATER INFORMATION <br />{80600:1} <br />1. (Page 9)- New Exhibit C -7 illustrates the stratigraphic column from the Fort Hays <br />Limestone down to the Dakota Sandstone, the first confined aquifer. Surface <br />water will not enter the confined aquifer system due to its depth and the <br />impervious shale formations overlying the aquifer. Discussion of the path of <br />meteoric water into confined and unconfined aquifers, as well as the Saint Charles <br />River is included in the attached revised pages G -1 and G -2. <br />2. (Page 9) - The water quality impacts of residual nitrates, nitrites and ammonia <br />have been considered as part of the mine plan. GCC Rio Grande proposes a <br />monitoring program to address the minimal possibility of nitrate, nitrite and <br />ammonia effects from blasting That monitoring proposal includes establishing <br />baseline ambient conditions in the St. Charles River, sampling of stormwater <br />mine discharges, and monitoring wells for groundwater which may be present at <br />the contact point between the Codell Sandstone layer and the underlying <br />impermeable shale. The monitoring plan is included as an amendment to Exhibit <br />G, at page G2. GCC has also committed to best management practices in the <br />handling of blasting materials to avoid nitrate spills. See revised Page G2. <br />3. (Page 9) - Process water discharges will range from approximately 6 gpm during <br />warmer periods to 3 gpm for colder periods when cooling water demands are less. <br />Process water will be piped to a lined pond for storage and evaporation. A pond <br />with a surface area of approximately 3 acres and a depth of approximately 3.5 feet <br />will provide up to 10 acre feet of storage to account for periods of low <br />evaporation rates or high precipitation. <br />4. (Page 9) - Domestic wastewater from the plant area will be disposed using a <br />septic tank(s) and leach field located north west of the plant area. The anticipated <br />flow rates are 7,000 gal/day, which will require a leach field area up to 4 acres in <br />size. <br />5. (Page 10) — As previously indicated, storm water will not be used for dust <br />suppression. GCC Rio Grande is negotiating a lease agreement with the Pueblo <br />Board of Water Works for 250 acre feet of water per year. The Pueblo Board of <br />Water Works approved the lease of water to GCC Rio Grande in June 2000. See <br />attached Appendix I. GCC Rio Grande is also designing its own deep well <br />system on the property to supply its water requirements. See, attached Appendix <br />E. Amended Exhibit G discusses the water supply plan for the project in more <br />detail. <br />