1987-12-01_PERMIT FILE - C1981017 ‎(100)‎

• Permit No: C1981017
• IBM Index Class Name: PERMIT FILE
• Doc Date: 12/1/1987
• Doc Name: Operation Plan-Permit Area
• Section_Exhibit Name: Chapter IIB
• Media Type: D
• Archive: No

Chapter II
have been designated A, B, C, D, E, F and G and are depicted on maps
11-B-App.7-Att.2 Plate 1 a-b and 2-7, which were prepared by Morrison-Knudsen Co.
in development of the Drainage Control System. The segments are:
Road Plate No. Description
A 2 Main arterial road for all mines.
B 2 Collector road from Mines 1,2 & 4.
C 3 Lateral road from Mine 4
D 4 Lateral road from Mines 1 and 2
E 5 Collector road from Mines 3 and 5
F 6 Lateral road from Mine 3
G 7 Lateral road from Mine 5
As described in the Morrison-Knudsen haul road study:
— This road system traverses very steep mountainous
terrain from the lowest elevation at 8,050 feet up to a
maximum elevation of 10,200 feet within a horizontal
distance that is less than 2 miles. The average road
surface gradients range from 2 to 9 percent.
— Severe road construction conditions have been
encountered on Roads C, D, and F to Mine 4, Mine
1 and 2, and Mine 3, respectively. These roads
have several long stretches with steep fill slopes.
Mid-Continent retained Geo-Hydro Consulting, Inc. to do further mapping and study
of the road system. The Geo-Hydro report, submitted in 1983, is contained in App.
V-E-2.
Geo-Hydro's study included bedrock and surficial geology, landslides and
avalanches, methods of road and bench construction and slope angles. The report
notes that:
— All haul roads were constructed in the Mancos Shale
and the Mesaverde formations.
— The Mancos Shale, which is common in Western
Colorado, and is known for rapid disintegration, has
relatively more favorable physical properties in Coal
Basin; numerous rock cuts in Mancos Shale are
stable even when excavated at very steep slope
angles.
— Landslides are relatively infrequent in Coal Basin,and
it appears no significant landslides are found in the
area of the haul roads.
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