REV104535

• Permit No: C1981010
• IBM Index Class Name: Revision
• Doc Date: 8/29/2002
• Doc Name: Adequacy letter
• From: DMG
• To: Trapper Mining Inc
• Type & Sequence: RN4
• Media Type: D
• Archive: No

4. Rule 4.08.4(1) requires all surface blasting to be conducted between sunrise and sunset. The
TMI pemut, on page 3-30, states this. Rule 4.08.4(1)(b) allows surface blasting to be conducted
between sunset and sunrise under the conditions described in Rules 4.08.4(1)(b)(i), (ii}, and (iii).
Please update the TMI permit to include a sentence that states that if TMI conducts any surface
blasting between sunset and sunrise, the requirements of Rules 4.08.4(1)(b)(i), (ii), and (iii) will
be complied with.
5. With regazd to the requirement of Rule 4.08.4(1) to conduct blasting between sunrise and sunset,
the Division recently encountered a situation at another coal training operation in Colorado where
the times associated with "sunrise" and "sunset" became an enforcement issue. To resolve this
issue, the Division agreed that the operation would utilize the sunriselsunset times provided by
an independent third-party reference source.
We would like to suggest that TMI also consider utilizing such a reference, for the purposes of
demonstrating compliance with the sunrise/sunset provisions of the Rule 4.08.4(1), should such a
demonstration ever be necessary in the future.
We suggest TMI consider referencing the sunriselsunset times provided on the Colorado
Division of Wildlife's website, found on Page 9 of the 2002 DOW Big Game brochure. This
publication maybe found on the Internet at www.wildlife.state.co.us/Brochuresl
BigGame/02generalinfo_tablecontents.pdf. Another potential source of independent third-party
sunrise/sunset times is the website www.sunrise/sunset.com. Adjustments for the Trapper
Mine's geographic location, as described in the DOW reference, would need to be made when
using either reference source.
Should TMI wish to utilize an independent source of sunriselsunset times for the purpose of
demonstrating compliance with Rule 4.08.4(1), the TMI permit would need to be updated to
reflect this.
Please be aware that utilizing athird-party reference source of sunrise/sunset times is not a
regulatory requirement. The Division, however, may, at times, refer to these sources of
information in order to verify TMI's compliance with the requirements of blasting between
sunrise and sunset.
b. The TMI Permit, with regard to compliance with ground vibration limits resulting from surface
coal mining operations, states on TMI permit page 3-32 that,
"The following calculations will be used when situations arise wherein
possible adverse impacts from blasting operations maybe present. The
equation to be used to calculate the pounds of explosive that can be
detonated in any eight millisecond (MS) period = M = (D/60)z where
M =Maximum charge weight per $ ms period. This is the standard
formula used by the Bureau of Mines (USBM) to limit vibration levels
to one inch per second peak particle velocity."
These sentences require updating to reflect the State of Colorado's current limits for ground
vibration at certain structures as described in Rule 4.08.4(10). To reflect the requirements of
C-1981-010 RN04/PROS 3 08/29/02