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STATE OF COLORADO <br />DIVISION OF RECLAMATION, MINING AND SAFETY <br />Department of Natural Resources <br />1313 Sherman St., Room 215 <br />Denver, Colorado 80203 <br />Phone: (303) 866-3567 <br />FAX: (303) 832-8106 <br />February 10, 2010 <br />Mr. Mac Schafer <br />Vice President <br />Castle Concrete Company <br />444 E. Costilla Avenue, <br />Colorado Springs, CO 80903. <br />Re: Technical Revision 14, Pike View Quarry, M-1977-211 <br />Dear. Mr. Schafer. <br />COLORADO <br />D I V I S I ON OF <br />RECLAMATION <br />MINING <br />- Si- <br />SAFETY <br />Bill Ritter, Jr. <br />Governor <br />James B. Martin <br />Executive Director <br />The Division has reviewed your request to allow Castle Concrete to use explosive charges, <br />placed in the existing scarps located in the southwest portion of the Pike View Quarry, to help <br />remove unstable materials within the current permit area. The main purpose of the requested <br />blast is to allow Castle Concrete's engineering staff safe access to the failure surface area, so <br />they can conduct their investigation and submit their recommendation on how to properly <br />establish a more stable post mining reclamation slope. The engineer's recommendations will be <br />submitted as part of reclamation permit amendment to the permit, to satisfy the Mined Land <br />Reclamation's Board Order that requires Castle Concrete, to submit a detailed reclamation plan <br />that will establish a safe and stable post mining slope no later than August 28, 2010. <br />In addition to the Division's review, the Colorado Geological Survey's staff reviewed the <br />submittal, and their comments and recommendations are attached to this letter. The Division is <br />requesting that Castle Concrete submit additional information as follows to clarify the submittal <br />with respect to the proposed blasting plan. <br />1) Please provide the detailed blasting plan and blast monitoring plan that will <br />implemented to protect off site impact to manmade structures from the proposed <br />blast. This plan must in compliance with Rule 6.5(4) and contain information sufficient <br />to evaluate its potential effectiveness and safety including the location, placement <br />and amount of each of the proposed charges. The blast monitoring plan must also <br />verify that the peak particle velocity that will be generated from the requested blast <br />will not exceed the calculated Velocity of 0.069 inches per second. <br />2) Agree to implement the Colorado Geological Survey's recommendations that are <br />listed on page three and four of their assessment of the technical revision that is <br />attached to this letter. <br />Office of Office of <br />M)ned Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines