2020-08-20_REVISION - M2009053

• Permit No: M2009053
• IBM Index Class Name: Revision
• Doc Date: 8/20/2020
• Doc Name: Amendment to an Application
• From: Robins Construction LLLP
• To: DRMS
• Type & Sequence: CN1
• Email Name: LJW
• Media Type: D
• Archive: No

SUMMIT ENGINEERING C 0 1 ENGINEERS & LAND SURVEYORS
Mail: P.O. Box 1897 Alamosa, CO 81101 P: 719-589-6147 E: [e-mail]
Memo to Kate Pickford 2 December 19,2007
$lasting Vibration Control Plan File No.M-2007-080
DISTANCE—FT. MINIMUM Ds MAX.CHARGE WT./DELAY,LBS.
11000 55 330.6
000 55 1,322.3
4,224(Haberkon House 55 5,898.2
5,000 55 8,264.5
5,100 65 6,156.2
2. Reference to the table above shows that the Scaled Distance Equation is rather restrictive for
blasting in close proximity to potentially affected structures. The nearby(within 200 feet)
structures to the proposed blasting are barb wire fencing,irrigation pond and pump,Las Mesitas
Ditch,and a farm service road.. There is an irrigation pivot 750 feet form the blasting location,and,
as mentioned above,there is a house owned by Mr.William Haberkon located 0.8 miles from the
blasting. The Scaled Distance Equation is designed to limit blasting vibrations to a point where
preexisting cracks in plaster walls will not extend or separate as a result of the vibration level
imposed. Therefore,the types of structures that are closer to the blasting than the Haberkon House
are not the types of structures that are very sensitive to blasting vibration,and the Haberkon House
is the logical control structure for proposed blasting operations. Reference to the table in item no. 1
above shows that 5,898 pounds of explosive could be shot in the proposed pit and be protective of
the Haberkon House. This amount of explosive is orders of magnitude greater than that proposed in
the permit application.
3. The Merritt Report suggests that pre-blast surveys of all nearby structures out to the Haberkon
House be conducted. The DRMS will make it a permit requirement to conduct pre-blast surveys of
the fences,fans road,pond and irrigation pump,and sprinkler. The pre-blast survey must be
conducted prior to initiation of blasting in the pit,and the pre-blast survey reports must be provided
to the DRMS for inclusion into the permit file. The DRMS endorses the Merritt Report suggestion
to conduct a pre-blast survey of the Haberkon House,but will not make such a survey a requirement
of the permit since the house is outside that one half mile radius in which pre-blast surveys are
typically required.
4.The DRMS requires all Operators using explosives to complete ablating report for each shot. The
report must be retained by the Operator for at least 3 years and be available for inspection by the DRMS
on demand. The record shall contain the following data:
a. Location,date,and time of blast;
b. Name,signature,and license number of blaster-in-charge;
c. Identification,direction and distance,in feet,from the nearest blast hole to the nearest
potentially affected structure,such as any dwelling,school,church,or community or
institutional building either
i. not located in the permit area;or
ii. Not owned nor leased by the person who conducts the mining operations.
d. Weather conditions,including temperature,wind direction,and approximate velocity;
c. Type of material blasted;
f. Sketches of the blast pattern including number of holes,burden,spacing,and delay patter.
Sketches shall also show decking,if holes are decked to achieve different delay times within a
hole;
Job # 1200710MP - A Page 73of78