GENERAL47111

• Permit No: C1981048
• IBM Index Class Name: General Documents
• Doc Date: 4/5/1983
• Doc Name: REVIEW OF TBMS RESPONSE TO STIPULATION 14 PN C-048-81
• From: MLRD
• To: MIKE SAVAGE
• Permit Index Doc Type: STIPULATIONS
• Media Type: D
• Archive: No

* III IIIIIIIIIIIII III
DEPARTMENT OF NATURAL RESOURCES
MorVe Pascoe. Executive Duector
•
MINED LAND RECLAMATION DIVISION
DAVID C. SHELTON Director
Ric hartl D Lamm
Governor
MEMURANUUM
5 it 1983
T0: Mike Savage ~~_
FROM: Jim Pendleton "
RE: Review of TBM' es nse to Stipulation #14, Permit #C-048-81
Pursuant to your request, I have reviewed Trinidad Basin Mining's
response to Stipulation No. 14 of their current permanent program
permit. The company basically reiterates the information which was
presented in its original permit application. This is inadequate to
satisfy the stipulation placed upon permit approval.
The company presents calculations for total excavated pit volumes,
coal volumes extracted and the resultant excavated overburden volume
(total pit volume minus the extracted coal). The implicit assumptions
made by the company are, (1) that the post-mining topography achieved is
essentially identical to that of the original pre-mining topography, and
(2) that all materials originally within the pits have been returned
during backfilling. The applicant has failed, however, to demonstrate
the validity of these basic assumptions.
The stipulation's third sentence reads; "This information shall
include discussion of previous pit volumes, pre- and post-mining
topography of previously mined areas, including proposed and existing
road configurations, ..." The purpose of this statement was to cause the
applicant to demonstrate the validity of their implict material balance
assumptions.
The applicant should complete a survey of the existing topographic
configuration of representative previously mined areas. By comparing
pre-mining and post-mining topographic mapping, the applicant should
demonstrate that all material movements have been taken into
consideration. Significant quantities of overburden which were
originally within the pits may now be residing in road embankments,
sediment pond embankments, stockpiles, etc. Until this uncertainty is
resolved, the applicant's implicit assumption (1) that the pre-mining and
post-mining topographies are identical, and (2) that all materials
originally within the pits have been backfilled cannot be verified.
cc: Brian Munson
Document No. 2140E
423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203 Tel. [phone]