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Grand River Park Project, M-2006-046 Response to Adequacy Letter of August 1, 2006 6 September 2006 Page 15 the maximum anticipated rate over the life of the mine. To provide a water quality effect, the basin design will incorporate the appropriate water quality control volume (WQCV) below the outlet elevation. This design and additional BMPs will be subject to review as part of the CDPS/NPDES permit for the site. It should be noted that a substantial amount of the site will runoff into the active mining areas and reclaimed groundwater lakes. These topographic features have abuilt-in water quality effect, by capturing and slowing water, to release sediments. Opportunities for infiltration will also keep sediments within basins, where they can be excavated, dredged, or simply integrated into natural soil- building processes on the site, Other than sediment - to be controlled as described above -pollutants are not generally used or encountered in a sand and gravel mining operation. Any pollutants and all water quality standards identified in the CDPS/NPDES process will be appropriately controlled in accordance with the regulations of the Water Quality Control Division. 23. In accordance with Rule 6.4.7(5), please affirmatively state that the applicant has acquired (or has applied for) a National Pollution Discharge Elimination System (NPDES) permit from the Water Quality Control Division at the Colorado Department of Health. The NPDES program is implemented in Colorado through the Colorado Discharge Permit System (CDPS) administered by the Water Quality Control Division. The applicant is aware of the relevant regulations and commits to applying for a CDPS permit when necessary. State and federal regulations are both triggered by the presence of an actual discharge, and both sets of regulations state that 180 days is the intended length of time to review individual discharge applications. See 5 CCR 1002 § 61.4(1)(c); 40 CFR 122.21(c)(1). Moreover, a General Permit (COG-500000) is the relevant regulation in Colorado for the purposes of a sand and gravel mine discharging only stormwater that is incidentally exposed to soil and sediment. This permit requires application for a CDPS permit 30 days prior to commencement of a discharge. COG-500000, paragraph I(A)(4). There will not be any discharge from the subject site for at least 180 days. The applicant prefers to wait until closer to the time of expected disturbance, and after approval of the DMG permit, before applying for a discharge permit. This approach is consistent with the DMG regulation (Rule 6.4.7(5)) that requires an operator to apply for a discharge permit when "necessary." The Division has previously acknowledged that this commitment is acceptable; please see the Rationale for Approval of Construction Materials Permit M-2004-067 ("This Office and the MLRB have consistently interpreted this rule to require the