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Memo to Berhan Keffelew 2 August 12, 2008 <br />Mine Pit and Blasting Vibration Review Permit No. M-1980-244, AM-09 <br />4. Although largely redundant to previous revision and amendment approvals for the Cresson Project permit, <br />the following is included here for the purpose of AM-09 conciseness. The Operator shall prepare a blasting <br />report for each shot. These reports must be retained by the Operator for at least three years and be available <br />for inspection by the DRMS on demand. The reports shall contain the following data: <br />a. Location, date, and time of blast; <br />b. Name, signature, and license number of blaster-in-charge; <br />c. Identification, direction and distance, in feet, from the nearest blast hole to the nearest potentially <br />affected structure not owned or controlled by the Operator; <br />d. Type of material blasted; <br />e. Sketches of the blast pattern including number of holes, burden, spacing, and delay pattern. <br />Sketches shall also show decking, if holes are decked to achieve different delay times within a hole; <br />f. Diameter and depth of holes; <br />g. Types of explosives used; <br />h. Total weight of explosives used per hole and maximum weight of explosives used per 8- <br />millisecond period; <br />i. Initiation system; <br />j. Type and length of stemming; <br />k. Mats or other protections used; <br />1. Type of delay detonator and delay periods used; <br />m. Number of persons in the blasting crew; and <br />n. Seismographic records, where required, including: <br />i. Type of instrument, sensitivity, and the calibration signal of the gain setting or certification <br />of annual calibration; <br />ii. Exact location of instrument and the date, time and its distance from the blast; <br />iii. Name of the person and firm taking the reading; <br />iv. Name of the person and firm analyzing the seismographic record; <br />v. The vibration level recorded <br />5. The Operator will conduct pre-blast surveys of potentially affected structures not owned or controlled by <br />the Operator that have not previously been surveyed, with survey results on file with DRMS. Pre-blast <br />surveys must be conducted at all structures located within one-half mile of the proposed blasting unless <br />persons in ownership or control deny access to the structures. Written requests to conduct pre-blast surveys <br />must be sent to owners of all structures a minimum of 30-days prior to initiation of blasting within one-half <br />mile. The Applicant must provide a plan for DRMS review and approval for the conduct of the surveys. <br />6. The Applicant proposes the installation at least one additional seismograph, in addition to those already <br />required by the permit, to be installed between areas of proposed blasting and potentially affected structures <br />in Cripple Creek. The DRMS will require that the location for the new seismograph(s) be established prior <br />to a decision on AM-09, and that the location for one of the seismographs be at the closest structure (to <br />include the underground workings of the Molly Kathleen), to proposed blasting areas at the north and west <br />extremities to be mined or be between the closest structure and the mine. <br />DRMS also has the geotechnical stability aspects of the valley leach facility and the overburden storage areas under <br />current review, but will withhold written comments on those aspects of AM-09 until the report of the third party <br />reviewer, Dirk Van Zyl, PhD has been completed and reviewed by DRMS. <br />cAacs files\My Documents 4-19-06 thru\cresson am9 mine slope review.doc