GENERAL34381

• Permit No: C1981037
• IBM Index Class Name: General Documents
• Doc Date: 2/19/1981
• Doc Name: GEC MINERALS INCS AMENDMENT TO DETAILED BLASTING PLAN
• From: MLR
• To: JIM PENDLETON
• Permit Index Doc Type: GENERAL CORRESPONDENCE
• Media Type: D
• Archive: No

STnTE OF COLORADO RIC H.~Rn D. ~nMM. Gavc~n nr III IIIIII IIIIIII III
999
DEPARTMENT OF NATURAL RESOURCES
D. Monte Pascoe, Executive Director
MINED LAND RECLAMA'T'ION
423 Centennial Building, 1313 Sherman Street
Denver, Colorado 80203 Tel. [phone]
David C. Shelton
Director
February 19, 1981
TO: Pete Evans
FROM: Jim Pendleton ~~
RE: GEC Minerals, tic's. mendment to 'Detailed Blasting Plan "'
Pursuant to your request I have reviewed GEC Mineral's "Amendment
to Detailed Blasting Plan", in order to determine whether it
satisfied my concerns regarding the original "Detailed Blasting Plan"
submitted by that operator for blasting to be performed within 550'
of the fuel storage facilities at the neighboring Dorchester Mine.
The amendment does appear to satisfy my earlier concerns:
1. The amendment by VME Nitro-Consult, Inc., includes additional
data collected during additional test monitored blasts at the
site. This additional data allowed them to improve the
confidence of their regression analysis of projected peak
particle ground velocities. Using this improved projection
they can now justify the utilization of charge/delay which
are roughly 2.16 times that allowed by the equation contained
in Regulation Section 4.08.4(10)(b).
2. The labeling deficiencies noted on the original report review
have been rectified to my satisfaction. It is now clear what
load and delay the first curve was prepared for and for what
peak particle velocity (1 in/second) the second figure is
projected.
3. GEC Mineral's cover letter states that they will continue
to monitor future blasts to assure conformance.
With these amendmets I can now recommend you approve GEC Mineral's
Blasting Plan, as a variance from the normal constraints of Rule
9.08.9 (10) (b) .