GENERAL31627

• Permit No: C1981033
• IBM Index Class Name: General Documents
• Doc Date: 12/11/2001
• Doc Name: FEDERAL LEASE COC-42481 PART 5 OF 8
• Permit Index Doc Type: Other Permits
• Media Type: D
• Archive: No

•
A. General Setting
CHAPTER III
THE AFFECTED ENVIRONMENT
The Bear No. 3 Mine is located at the southwestern extremity
of the Piceance Creek Basin in the Paonia Coal Field. The
coal is mined from the Upper Cretaceous Mesa Verde
Formation. The formation is overlain by the Ohio Creek
Conglomerate, then the Wasatch Formation of early Tertiary
age and Quartz Monzonite porphyry of Tertiary age. The Mesa
Verde Formation is underlain by a 2000 to 3000 foot sequence
of Mancos shale, a result of the Cretaceous Mancos seas.
The coal is mined from the C and B seams of the lower coal
member or "Paonia Member" of the Mesa Verde Formation. The
lower coal member averages some 270 feet thick and bears
three minable coal seams. The strata in the mine area dips
from 3 to 5 degrees in a north-northeast direction. The C
seam ranges from 4 feet to 9 feet in thickness while the B
seam averages around 25 feet thick. The coal is a low
sulfur, low ash, moderate BTU, and is classified as a
bituminous coal considered excellent for steam and domestic
uses.
The area is characterized by deeply dissected terrain with
steep slopes in the drainage of the North fork of the
• Gunnison River. Much of the area is overlain with colluvial
sand deposits from various types of mass wasting, including
a large landslide in Section 17. The facilities area is on
a 500 year flood plain terrace of the North fork of the
Gunnison.
Climatic conditions in West-Central Colorado are variable
due to the extreme topographic changes in the region;
consequently, many extremes are prevalent. The mine site
area has a semi-continental climate that receives about 15
inches of precipitation yearly mainly occurring in the fall
and winter months. The mean annual temperature for Paonia
the nearest meteorological station for which data is
available is about 49°F, the climate is generally favorable
for fruit growing (apples and cherries). Winds generally
are channelized by the North Fork Valley that runs
east/west.
Particulate air quality in the study area ranges from 20 to
132 micrograms per cubic meter (ug/m') annual geometric mean
as recorded at sixteen state, municipal, and private
operated particulate sampling sites. In undeveloped
sections, particulate concentrations range for 20 to 40
ug/m~. There has been no measurement of carbon monoxide,
Hydrocarbon, nitrogen oxides, sulfur dioxide, or other