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subject: Steven G. Vick's Planning, Design, and Analysis of Tailings Dams, 1990 and the US Army Corps of <br />Engineers (USACE) Slope Stability, EM 1110-2-1902. <br />Your email also is requiring us now to change our impoundment outslope angle to 2H:1 V for <br />reclamation/revegetation purposes. The assertion that vegetation will not become established on slopes steeper than <br />2H:1 V can be readily disproved by simply observing the natural mountain environment and the revegetation of <br />embankments all along our highway system done by CDOT. Again, where does this "requirement" come from? <br />Rule 3.1.5(9) states: Maximum slopes and slope combinations shall be compatible with the <br />configuration of the surrounding conditions and selected land use. In all cases where a lake or <br />pond is produced as a portion of the Reclamation Plan, all slopes, ..., shall be no steeper than a <br />ratio of 2: L.. " <br />Rule 6.3.4 (b) Exhibit D - Reclamation Plan states: "spec6 the maximum gradient of reclaimed <br />slopes ... If the applicant proposes slopes steeper than 3:1, the Operator/Applicant must include a <br />justification that supports steeper slopes for the proposed post mining land use, and demonstrates <br />compliance with the-applicable performance standards of Section 3.1. " - <br />Our reading of Rule 3.1.5(9) and 6.3.4(b) does not preclude slopes steeper than 2:1 for the reclamation of a pond or <br />3:1 for other reclamation. No pond is proposed for final site reclamation. No excavated slopes are proposed other <br />than for construction of the tailing dam. These areas will have tailings deposited. <br />The geotechnical evaluation shows the slopes will be stable. The proposed reclamation plan will result in a site <br />resistant to wind and water erosion. The only comment from the NRCS was to the seed mix for the site and did not <br />question the reclaimability of the site based on the proposed plan or its long term erosional stability. Given the small <br />area to be reclaimed on an annual basis (the largest face area to be reclaimed in a phase, is Bench 44 at over 74 <br />months ... consisting of approximately .84 acres.) reclamation will not preclude hand and/or small equipment <br />reclamation. It will not be necessary for large reclamation equipment to have access to the site and operate on steep <br />slopes. <br />We are confused because we asked in numerous letters and meetings for the DRMS to recommend an acceptable <br />outslope angle and in your letter of October 4a' you, after "careful consideration", stated that the earlier position <br />taken in the DRMS Second Adequacy Review would stand. It is very difficult to prepare a design with ever varying <br />positions and "requirements". We request the DRMS affirmatively state, given Venture Resources' commitment to <br />use Synteen Technical Fabric and other associated documentation, that an outslope angle of 1.5H:1 V will be <br />acceptable for stability and reclamation. <br />A Compromise Condition: <br />If we are able to meet the requirements you now prescribe, you suggest a conditional approval may be granted for <br />tailings disposal to the top of the dam, referred to as the Barrier Bench level in our permit work. This area would <br />only take 2-3 months of operation, in effect denying Venture Resources the ability to operate. This is unacceptable <br />and is a mockery of the engineering analysis we have done. With a physical concrete structure acting as a barrier, the <br />tailings have nowhere to go. The DRMS wants us to demonstrate an unsaturated tailings condition throughout the <br />entire Barrier Bench level profile. To do so would require Venture Resources to expend a huge capital investment <br />with little assurance of the ability to proceed forward. <br />A more appropriate, and acceptable, conditional approval would be allowing us to buildout through Bench #2 <br />incorporating the geogrid as we have suggested. At this stage, the factors of safety are well within the requirements <br />of the September 8`h Second Adequacy Review. Our permit work is also structured in this fashion to incrementally <br />address the reclamation bond in two stages. Risk is limited and there is a meaningful period of time to demonstrate <br />consolidation and drying. Even if there is failure, the Sedimentation Collection Pond would act as a secondary <br />"trap" containing most, if not all, of the tailings to our property. Given the varying requirements already asked of us, <br />we would request the DRMS to EXACTLY prescribe the approval conditions to allow us proceed to the next <br />benches, Bench #3 - #5. <br />Page 2 of 3