Laserfiche WebLink
• <br />III IIIIIIIIIIIII III ~ <br />ROCKY MOUNTAIN CONSULTANTS, INC. <br />May 16, 2001 <br />Mr. Thomas A. Schreiner <br />Envirorunental Protection Specialist <br />Division of Minerals and Geology <br />1313 Sherman Street, Room 215 <br />Denver, Colorado 80203 <br />(first initial, <br />RECEIVED <br />MAY 18 ppp~ <br />Division of Minerals and Ceologp <br />Inc <br />Premiere Building <br />825 Delaware Ave.. Sulie 500 <br />Longmont, CO 80501 <br />(303) 772-5282 <br />Metro (303) 665-6283 <br />FAX (303) 665-6959 <br />last name)@long rmcco.com <br />RE: Aggregate Industries, Inc. Fredstrom Site -Regular 112 Adequacy Review #M-2001-016 <br />Dear Mr. Schreiner: <br />Following is our response to the questions you raised in your adequacy review. <br />6.4.4 EXHIBIT D - Minine Plan <br />Prior to mining the site, the applicant will obtain a Flood Hazard Development Permit (FHDP) with <br />Boulder County. The purpose of this permit is to ensure that permanent structures are safe from <br />flooding and that the proposal complies with the Boulder County code and Federal Emergency <br />Management Agency standards. RMC will provide the Division with a copy of this permit upon <br />request. <br />The sequence of proposed mining activities is generally downstream to upstream with previously <br />mined pods being reclaimed prior to full mining of the next pod. Reclamation of pods will include <br />establishing stable slopes (3:1 typical) with overburden materials. Reclaimed pods will 611 with <br />water providing energy dissipation and thereby erosion protection of the reclaimed pods. <br />Excavating each pod from downstream to upstream would further reduce the potential for erosional <br />damage outside the pods. Peak velocities will be calculated and erosion protection for structures <br />will be designed as part of the FHDP for this site. Flood control structures are not planned at this <br />time. <br />Flood water outside of the floodway typically rise gradually and would initially flow across the site <br />into the mining pods in a shallow sheet flow. Shallow sheet flow has law erosion potential. The <br />flow into each pod located outside the floodway would gradually increase with time and would <br />eventually become erosive. However, the initial sheet flow inflow would pool at the bottom of the <br />open pod helping to provide energy dissipation and thereby erosion protection at the embankment <br />toe. More detail in this regard will be available after the application for the FHDP is completed. <br />CIVIL AND ENVIRONMENTAL ENGINEERING PLANNING <br />