_GENERAL DOCUMENTS - C1981017 ‎(128)‎

• Permit No: C1981017
• IBM Index Class Name: GENERAL DOCUMENTS
• Doc Name: Bid Documents ‎(IMP)‎
• Permit Index Doc Type: General Correspondence
• Media Type: D
• Archive: No

C.c �0 DEPARTMENT OF NATURAL RESOURCES
�Q O David H. Getches, Executive Director
° MINED LAND RECLAMATION DIVISION
DAVID C.SHELTON,Director
1876
Richard D Lamm
Governor
September 20, 1983
r--
T0: Jim Herron
3 _
FROM: Jim Pendleton \
RE: Mid-Continent Resources' Request for Revision of Subsidence Monitoring
Provi sio►fs for Permit No. C-017-81
Pursuant to your request, I have reviewed the subsidence monitoring report
submitted by Mid-Continent Resources for their Coal Basin Mines. I have also
reviewed the letter requesting a revision of their subsidence monitoring
program in effect at the Coal Basin Mines, as contained in Permit No. C-017-81 .
In response to market and mining plan changes at the Coal Basin Mines,
Mid-Continent Resources requests amendment of their monitoring plan. The
DOE/USBM monitoring program above the No. 3 mine has been terminated and the
monuments removed without prior notice by the United Stated Bureau of Mines'
contractor. Subsidence monitoring to date has determined that subsidence
response has been relatively rapid above the longwall mine workings.
Insufficient data exists to date to determine site-specific subsidence
parameters, such as the angle of draw. A maximum vertical subsidence of
1.27 feet has been observed with no reported discreet surface artifacts
observed by the operator.
The operator expresses the opinion that "A determination of 'angle of draw' or
the position of the U.S. Forest Service concerning adjacent lands" are not of
first-order importance, because it will be several years before the
underground mining operations approach the permit boundary, and the operator
hopes that the U.S. Forest Service can be prevailed upon to reconsider its
denial of "surface subsidence releases" for Forest Service adjacent lands. I
concur with Mr. Bowman's opinion, but offer three observations for the
operator's benefit:
(1 ) The stipulation placed upon the original permit remains in force and
states; . . THE EXTRACTION OF COAL SHALL BE LIMITED TO THOSE AREAS DEFINED
BY THE PROJECTION OF THE LEASE PERIMETERS TO THE DEPTH OF THE COAL SEAM BEING
EXTRACTED, ALONG AN ANGLE OF DRAW OF 20.50 FROM VERTICAL. THIS LIMITATION
SHALL REMAIN IN EFFECT UNTIL THE COMPANY HAS VERIFIED, TO THE DIVISION'S
SATISFACTION, THAT THE ACTUAL SITE-SPECIFIC ANGLE OF DRAW VARIES FROM 20.50,
THROUGH IMPLEMENTATION OF THE PROPOSED SUBSIDENCE MONITORING PROGRAM."
(2) The operator is encouraged not to procrastinate in the determination of
the angle of draw, because the requirements of that stipulation will be
enforced.
423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203 Tel. [phone]