PERMFILE120021

• Permit No: M2006016
• IBM Index Class Name: Permit File
• Doc Date: 5/1/2006
• Doc Name: Application Adequacy Issues
• From: Douglas L. Cooper
• To: DMG
• Media Type: D
• Archive: No

,,/~.~ N~ v Doa~las L. G~n~er
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May 1, 2006
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Colorado Division of Minerals & Geology
Durango Field Office
701 Camino del Rio, Room 125
Durango, Colorado 81301
Attention: Wallace H. Erickson
Subject: Perkins Sandstone-- Application Adequacy Issues ~'
112 Application No. M 2006-016 ,~
Deaz Mr. Erickson:
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The following response to your Adequacy Issues has been prepared in consultation with the applicant, and
corresponds with the same numbers in your list.
Adeauacv Item #1)
i. The application indicates that explosives will be utilized. Pursuant to Rule 6.4.40) and
5.5(4), please submit the appropriate analyses which demonsbate that offsite areas will not
be adversely affected by blasting. DMG recommends that the analyses address all svuctures
within one mile of ti-e permit boundary.
Mc Stone Response #1:
The blasting contractor, Mr. Rusty Bauer of Bedroc Blasting, has extensive blasting experience within the
local area and especially with the subject Dakota Sandstone at this site. He utilizes the Bureau of
Reclamation blasting safety guidelines, are OSHA compliant, MSHA trained, and qualify as a licensed,
insured blaster.
Blast vibration data is available from published values of the explosives manufacturer. "When an explosive is
detonated in the ground, three types of seismic waves are generated. Compressive, shear and surface. These waves
can result in stucture response and on rare occasions, structure damage. Extensive research has provided for safe
blasting criteria based on peak pa-ticle velocity measured from the wave event" ' Calculations using Dyno Nobel
data show that it is relative simple to limit the shock vibration (acceleration) to a structurally safe %2-inch per
second squazed, out to a 10,000.foot radius within a continuous hazd-rock bed.
The initial blasting plan for the project proposes 3Y:-inch drilled hole diameter for an 8-foot center-to-center
pattern in 24- to 36-foot hole depths and 10- by 10-hole rows, Using the following ...
• 17 milli-second trunkline & 25 milli-second lateral delays,
• ANFO Dynomix explosive charge
• Red-HB, EZ-Detsnnn-electric (gas) initiation
A powder factor of 1.00 #/CY will frachue a volume of 56.89 CY per hole per delay (24-foot depths) with
56.89 pounds of explosive.
'Explosives Etu>;neers' Guide, ®~! G9 ® try o ®¢ a