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Rule 6.4.5 Exhibit E -Reclamation Plan 5. Section (a) of Exhibit E states that the Reclamation Plan shall include a description of the types(s) of reclamation the Operator/Applicant proposes to achieve in the reclamation of the affected land, why each was chosen, the amount of acreage accorded to each, and a general discussion of methods of reclamation as related to the mechanics of earthmoving. The applicant states that the post mining land use will be a combination of water storage and future development. Please state the acreage associated with each proposed land use. Additionally the Applicant/Operator has submitted multiple seed mixes to be used in reclamation, based on the azeas where the seed will be planted. Please state the acreage associated with each of the seed mixes presented in the reclamation plan. 6. The applicant proposes to reclaim portions of the site as water storage with ponds surrounded by shiny walls. Enclosed, please find a copy of the Division's guideline titled, "Guide to Specification Preparation for Slurry Walls and Clay Liners as a Component of a Colorado Mined Land Reclamation Permit." As noted in this guideline, operators may choose the option to bond for 100% installation or replacement cost of a slurry wall or pit liner or may select a regulated construction option and become eligible fora 20% installation or replacement bond. The guideline contains information that must be submitted by the applicant to be eligible for the 20% bonding option. Please inform the Division if the applicant intends to bond for 100% of the slurry walls, or will provide the necessary information for the 20% bonding option. Rule 6.4.7 Exhibit G -Water Information 7. Section (5) of Water Information requires the Operator/Applicant to affirmatively state that the Operator/Applicant has acquired (or has applied for) a National Pollutant Dischazge Elimination System (NPDES) permit from the Water Quality Control Division at the Colorado Department of Health. The application indicates that this permit has not yet been applied for. Please be awaze that tfie Operator/Applicant must acquire this permit prior to the discharge of any water from the site. 8. The applicant should be awaze that 3.1.6 (I) of the Construction Material Rules and Regulations requires that disturbances to the prevailing hydrologic balance of the affected land and to the surrounding azea and to the quantity and quality of water in surface and groundwater systems both during and after the mining operation and during reclamation shall be minimized. In that the proposed operation includes dewatering of the pits and installation of slurry walls, the potential for impacts to groundwater exists. Please indicate how the hydrologic balance of groundwater in and azound the permit site will be monitored. 9. In accordance with Rule 6.4.7(2)(b), the Division requests that the applicant identify and chazacterize the aquifer to be mined in or through. The Division also requests that the applicant define or predict the cone of depression expected for any azeas to be dewatered and dry mined during the life of the operation. The cone of depression assessment should define, at a minimum, the horizontal and vertical extent of drawdown expected. If during the assessment, the applicant determines that a drawdown will occur offsite that may impact a current groundwater user, the applicant should explain any mitigation measures to be implemented and trigger points that would put mitigation measures into effect. 10. Please describe how the drawdown of the pit will impact the stmctuml integrity of the surrounding wells and surface water drainages. 11. Based on the information provided in the application and information obtained from Poood Insurance Rate Maps, much of the site lies within the 100-yeaz floodplain (and possibly within the 10, Z5, & 50-yeaz floodplains) of the Big Thompson River. In the event of a significant flood event (10-yeaz flood or greater) it is likely that the existing pits and/or reclaimed lakes will be captured by the Big Thompson River. Please refer to the enclosed memo from Allen Sorenson, DMG, addressing this issue. Rule 6.4.12 Exhibit L -Reclamation Costs 12. The Division will estimate the cost to reclaim the site once the applicant addresses the concerns noted in this letter. 13. The 5 percent administration cost element required under §34-32.5-117(4)(b)(I) must be applied to the sum of the direct costs (total disturbance costs) and the indirect costs (mobilization plus overhead); in the Applicant's Table for Reclamation Cos[ Estimate the 5 percent administration cost had only been applied to the direct cost.