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Pagel 3 <br />State Adequacy Review Response Letter.doc <br />Comment: Please demonstrate the proposed size of the sediment ponds will be adequate to <br />handle surface inflows during peak: rainfall events. In addition, all water must be <br />able to infiltrate within 72 hours or a well permit and substitute water supply plan <br />roust be obtained from the Office of the State Engineer. Please demonstrate that <br />water will be able to infiltrate into the substrate within 72 hours. <br />Response: The Drainage Letter and Calculations provided to Weld County have been <br />attached to Exhibit D for reference. The sediment ponds will have pumps <br />rated at 150 gpm with floating suctions lines. This will drain the ponds in <br />less than 72 hours. <br />Comment: The Mining Plan Map shows the topsoil stockpiles, stormwater ditches and <br />sediment ponds will be located within 8 feet of the permit boundary. Will the <br />Operator have enough room to install and reclaim these structures without <br />affecting land outside of the permit boundary? Please be aware that any <br />disturbance which occurs outside of the permit boundary could result in a <br />possible violation of the conditions of 'the permit and the Construction Material <br />Rules and Regulations. <br />Response: The topsoil stockpile berms will need to be kept a minimum of 8 feet from the <br />pit boundary to allow for vehicle access for temporary seed application. A <br />note to this affect has been added to the Mining Plan Map and Exhibit D <br />item (b). Reclamation of all structures can and will be performed from <br />within the pit boundary. <br />Exhibit E - Reclamation Plan <br />Comment: Please specify the amount of wood fiber mulch to be applied per acre. Also, <br />indicate iffertilizer will be used. <br />Response: This Exhibit has been revised to clarify the approach to seeding and <br />mulching. Wood fiber mulch will not be used for reclamation. Fertilizer will <br />not be used. <br />Exhibit G - Water Information <br />Comment: The Applicant has stated water will only be used for dust control. As required by <br />Rule 64.7(3) and (4), please provide an estimate of the project water <br />requirements on an annual basis and indicate the source of water to supply the <br />project water requirements. <br />Response: The estimated project water for dust control will be 6.2 acre-feet per year. <br />The source of water to supply the project water requirements is a well <br />located in the general area and permitted for this use. The well permit <br />number is 69713-F and is located in the NE t/4 of Section 4, T10N, R61.W, of <br />the 6th P.M., Weld County, CO. <br />Comment: The Applicant has stated a National Pollutant Discharge Elimination System <br />(NPDES) permit will be obtained. However, the Applicant has stated all <br />stormwater will be retained onsite. Please explain why an NPDES permit would <br />be obtained. <br />Response: The mining plan has been revised and the temporary sediment ponds will <br />have a pumped discharge. A Stormwater Discharge Permit Associated with <br />Sand & Gravel Mining and Processing will be required.