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MAY-01-06 11:25 AM DOUG CONGER 97B 565 <br />~J`~ ~ ~ Nx~e< 4. Canplx <br />711 I~YPIBOQ lNBd <br />Carttsr, GI X1391-M14f1 <br />May 1, 2006 <br />l j t Colorado Division ofMinerals lk Geology !// <br />r Durango Field Ofiice <br />701 Camino del Rio, Room 125 <br />Durango, Colorado 81301 <br />Attention: Wallace H. Erickso~ ~`'`~ <br />Subject: Perkins Sandstone -Application Adequacy Issues' <br />112 Application No. M 200ti-016- V~,~- - - <br />Dear Mr. Erickson: <br />8394 P,. 01 <br />dconaa[~p~bralnslgfm.nat <br />vt~: 19~0~ sas-aaa4 <br />(Vok• - F•x - MwN•p•1 <br />Re~~~ed <br />puran ~`~3 3s &G oto9Y <br />~Niston°t ~ <br />The following response to your Adeyuacy Issues has been prepared in consultation with the applicant, and <br />corresponds with the same numbers in your list. <br />~et~acv Item l+ 1 <br />7. The appllcatlon lndlcates that exp/os/vas will be utlllzed. Pursuant to Rule 6.4.4(1) and <br />8.6(4), please submft the appropriate ana/ysea which demonstrate that oM-site areas will not <br />be adtremely effected by blaaf/ny. OMG reeommenda that the analyses sddross al! structures <br />with/n one mile of the permk boundary. <br />M~ Stones n~ N 1; <br />The blasting contractor, Mr. Rusty Bauer of Bedroc Blasting, has extensive blasting experience within the <br />local area and especially with the subject Dakota Sandstone at this site, He utilizes the Bureau of <br />Reclamation blasting safety guidelines, are OSHA compliant, MSHA trained, and qualify as a licensed, <br />insured blaster. <br />Blast vibration data is available from published values of the explosives manufacturer. "When an exploshre k <br />detonated in the ground, three types of selsmk waves are generated: Compressive, shear and surface. These waves <br />can result in shuclure response and on rare occasions, shucture damage. Extensive research has provided for safe <br />blasting criteria based on peak parfide velotr7ymeasured hom the wave event"' Calculations using Dyno Nobel <br />data show that it is relative simple to limit the shock vibration (acceleration) to a structurally safe's:-inch per <br />second squared, out to a 10,000-foot radius within a continuous hard-rock bed. <br />The initial blasting plan for the project proposes 3'/i-inch drilled hole diameter for an S-foot center-to-center <br />pattern in 24- to 36-foot hole depths and 10- by IO-hole rows, Using the following ... <br />• 17milli-second /runkline & 25 milli-second lateral delays, <br />ANFO Dynomix explosive charge <br />Red-HB, li7-Dets non-electric (gas) initiation <br />A pmvder jactnr of 1.00 H1CY will fracture a volume of 56.89 CY per hole per delay (24-foot depths) with <br />56.89 pounds of explosive. <br />'plosives En~incer~' Guide. (Li 57 G4 ~ (~I o®as <br />