2013-10-02_PERMIT FILE - C1981019A ‎(2)‎

• Permit No: C1981019A
• IBM Index Class Name: Permit File
• Doc Date: 10/2/2013
• Section_Exhibit Name: 2.06 Requirements for Permits for Special Categories
• Media Type: D
• Archive: Yes

RULE 2 PERMITS
STIPULATION No. 7
"The Permittee will accomplish inspections of the Streeter Canyon Fill and
submit Certified Inspection Reports to the Division in accordance with the
requirements of the plan designed in accordance with Rule 2.06. These
inspections and Certified Inspection Reports will include specific examination
and discussion of the facial conditions of the fill, in order to determine whether
the development of perched water tables within the fill is affecting its surficial
slope stability. Further, if the required engineering inspections determine that
surficial slope failure conditions are imminent, or if surficial slope failure
manifests itself within Streeter Canyon Fill, the Permittee will prepare and
submit to the Division detailed engineering plans to abate any imminent or
manifested slope stability problem. Any appropriate remedial activity shall
commence immediately following the approval of the detailed engineering plans
by the Division."
For information regarding these monitoring requirements, refer to the 1983 - 1989 Annual Reclamation
Reports.
The following is the original narrative from the original application under Section 2.06.2, Experimental
Practices Mining for the Streeter Fill to be permitted as an Experimental Practice.
On September 4, 1979, Colowyo applied for a permit allowing the company to engage in an experimental
practice for the construction of a spoil fill area within the permit boundaries. A copy of this application is
set forth in Exhibit 12, Experimental Practice Information. The information contained in this section
summarizes the need for an experimental practice and the ability to achieve environmental protection that
is equal to or greater than that required by the performance standards of Section 4.09 for excess spoil.
Spoil from the initial box cut for mining south of Streeter Draw will not be required to achieve the
approximate original contour within the area where overburden has been and will be removed. The
location of the fill (Streeter Fill) is shown on the Existing Structures - South Map (Map 12). The planned
final topography following mining is shown on the Post-mining Topography Map (Map 19), with the area
on the map that comprises the Streeter Fill being that area to the north and east of the line on the map that
outlines the area to be mined. The fill design is shown on the Fill Design - Experimental Practice Map
(Map 30).
Background - Streeter Fill
Prior to the startup of mining operations at Colowyo, several geotechnical engineering studies concerning
the spoil material were undertaken for the mine site. This work was used to evaluate and ensure stability
of the backfilled material and fill areas. Exhibit 23, Experimental Practice Information, contains the
following studies developed for spoil stability prior to mining: Report on Preliminary Design of Open Pit
Slopes (April, 1975), and Report on Preliminary Design of Waste Dumps (November, 1975).
The construction of the fill in Streeter Draw began in January, 1977. Streeter Fill had been approved as
part of an interim mine plan to produce 250,000 tons/year from the "X seam" only, both by the United
States Geological Survey (USGS) in an approved federal mining plan pursuant to the regulations at 30
CFR Section 211.10 and by the Colorado Mined Land Reclamation Board (MLRD) in Extraction and
Development Permit Number 76-15 C/A.
Rule 2 Permits 2.06-2 Revision Date: 6/23/08
Revision No.: MR-91