PERMFILE67333

• Permit No: C1981053
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: 4.0 PERFORMANCE STANDARDS
• Media Type: D
• Archive: No

Herein is the response to the attached memorandum fn-~n Steve Renner pertaining to
subsidence control:
1. Blue Flame Coal Mine will adopt the 21 degree angle of draw and a maximun
overburden thickness figure of 300 feet proposed by the Division. It may
be expected that subsidence features will be expressed on the surface up to
115 feet away from the barrier pillar after mining is cor~leted. The permit
boundary, i.e., the areal placement of the barriers, has been modified to
ensure a 115 foot subsidence buffer.
2. Blue Flame Coal Mline has identified the Huntington ditch as the only renew-
able resource existing on the surface above the permit area. Blue Flame Coal
Mine has sutrnitted a detailed map which overlies the mine plan. This map ac-
curately depicts topography, existing roads, the Huntington ditch, ephemoral
drainages, any existing structures and the subsidence monitoring points as
described in 3 and 4 below.
3. The proposed subsidence monitoring stations have been modified to accurately
quantify movement. 1'he proposed Southernmost point, point number 2, has been
rPoved 200 feet West so it will not be affected by the inactive workings of
the old mine. A fourth monitoring point, point number one, has been estab-
lished 250 feet Fast of the West permit boundary line and 110 feet North of
the South permit boundary line. The Northernmost monitoring point, point
number 4, has been moved 350 feet West of its proposed location. Point 3, the
tJOrthwesternmost point has not been changed fmn the proposed location.
4. One reference point has been established off any areas potentially affected
by subsidence. Blue Fleune Coal Mine has adopted the Division's recommenda-
• tion that this monument be established at least 130 Eeet South of the face of
- the South barrier pillar and 150 feet West of the Westernmost extent of the
old mine workings.
5. Monitoring of the subsidence rmnument network will take place at least twice
prior to any undergzbund development work in order to establish a base line
data. This monitoring will take place after the Mined Lind Reclamation Div-
ision permit has been obtained and previous to approaching within 115 feet in
any direction of any subsidence monument.
6. Blue Flame Coal Mine crnmits to a quarterly annual monitoring filing the first
}'ear and will continue monitoring on a quarterly basis throughout the life of
the mine.
7. For purposes of reporting subsidence monitoring data, the following informa-
tion will be provided on a semi-annual basis:
a. Survey data which has been tabulated and reduced stwll be sutxnitt~l by
the engineer.
b. Five (5) subsidence profiles ~~~ill be sutrnitted. Thr;e profiles, which
will be adequ~~Cely deta.ileci ~~.nd certified by a registered professional
engineer, shell exrend bet~oe_•n points 1 and 2, 1 and 3, 2 and 3, 2 and 4,
and 3 and 4. rah point ha_ been nur~~::r.red as per the r_cxnnent number 3
• above.