2011-06-20_REVISION - C1981019 ‎(5)‎

• Permit No: C1981019
• IBM Index Class Name: Revision
• Doc Date: 6/20/2011
• Doc Name: Revised 5/23/2011 Rule 2
• Type & Sequence: PR3
• Media Type: D
• Archive: No

RULE 2 PERMITS
lines within the Colowyo existing permit area is included in Volume 8, Map 22A. Proposed power lines
for the Collom permit expansion area are shown on the Structures and Facilities map (Map 22B). One
power line is planned to bring power to Collom area, as shown on Map 22B.
Electrical power lines located in the permit area will be constructed in accordance with requirement of
Section 4.18 to minimize potential electrical hazards to large raptors.
The major piece of equipment that will be powered by electricity in the Collom area is the shovel.
Therefore, during the life of the mine it is necessary to periodically move the existing power line loop to
accommodate the advancement of the pit.
Haul and Access Roads
A haul road will be constructed to facilitate mine traffic from the primary crusher to the Gossard load out
facility located northeast of the proposed pits. This approximate 6 mile long haul road will be constructed
to meet the specifications and standards set forth in Rule 4.03.1 (See Map 25E, Sheets 1 -9). The
proposed haul road will be constructed a crown, and constructed upon the most stable available slope
to minimize erosion. Overall grade of the road will not exceed l OH: l V with a horizontal alignment
consistent with the existing topography. Ditches, erosion controls, and culverts will be used to minimize
impacts to surrounding areas, and will be designed in such a manner to safely pass peak runoff from a 10
year, 24 hour precipitation event (Please see Exhibit 24, Item 1 — Collom Haul Road Culverts).
Additional design information for the Collom Haul Road is listed in the Construction Notes section of
Sheet 3 of 9, on Map 25E. This road is specifically designed to meet the applicable haul road regulations
as well as Rio Tinto internal road design guidelines while minimizing additional disturbed area and
preventing environmental damage. As shown on Map 25E, the maximum sustained road grade is about
5.1 %. Cross fall slopes between centerline and road shoulders shall be between 1 and 2 percent as
directed by the field engineer. The road shall have an overall width of 100 feet, with a 24 foot paved
running surface as shown on the cross - sections. The road length is about 29,000 feet.
Asphalt pavement specifications shall be based on a 30 year design life with a 15" thick base course
(gravel) and 8.5" asphalt thickness. The pavement design is based on 50 ton coal haul trucks with axle
loads of about 81 psi. This specification assumes an R -20 silty sand subgrade material. Base course shall
be CDOT Class 6 aggregate. A 6 foot high berm shall be used at all locations where the roadway is
elevated. Cut slopes shall be 0.5H: IV or less when completed in competent rock. Elsewhere, cut slopes
in unconsolidated materials shall be laid back at 2H:IV or less as directed by the field engineer.
Requirements for fill placement shall be as specifically described in Rule 4.03.1 Haul Roads (3) (e) `Road
embankments ". A ditch shall be installed at toe of all cut slopes. If needed, temporary erosion control
measures shall be implemented during construction to minimize sedimentation and erosion until
permanent control measures can be established.
There are three main haul roads that will be built to haul overburden materials from the pit to the
temporary overburden stockpile. These are shown on Map 25D and are designated as the West, Central,
and East Haul Roads. The East Haul Road will also be used from the pit to haul coal to the truck dump.
This road configuration is needed given the valley configuration, the planned depth of the pit, and the
spoilpile design. These three roads have been designed to meet the applicable portions of Colorado
DRMS Rule 4.03.1 for Haul Roads.
All three roads are designed with an overall width of 120 feet as shown on the cross - sections. The West
Haul Road has a design length of about 5,300 feet and a maximum sustained slope of about 3.0 percent.
The Central Haul Road is the lowest in elevation and will eventually tie into the floor of the pit. It is
Collom — Rule 2, Page 96 Revision Date: 5/20/11
Revision No.: PR -03