GENERAL32961

• Permit No: M1999002
• IBM Index Class Name: General Documents
• Doc Date: 8/18/1998
• Doc Name: COMMERCIAL MINE PLAN SUBMITTED TO BLM SECTION 7
• Media Type: D
• Archive: No

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Table 7-5 Project Vicinity Climatic Conditions.

Location Elevation
(feet
MSL) Maximum
Temperature
(°F) Minimum
Temperature
(°F) Normal
Temperature
{°F) Growing
Season
(Da s)
Precipitation
(inches)
Grand
Junction
4,855
102
-8
52.7
204
8.41
Ran el 5,216 98 -16 43.8 77 8.24
Rifle 5,400 92 -27 47.8 129 11.24
Glenwood
S rin s
5,823
97
-14
48.1
75
18.03
Little Hills 6,140 92 -30 43.5 68 10.62
Meeker 6,347 108 -25 42.6 60 11.09
Source: U.S. Department of Commerce 1968, cited in USGS 1981
year with temperatures below 32°F. However, of the latter, only 24 days a year stay
below freezing all day.
An inversion, a stable atmospheric condition common to the Piceance Creek Basin
and Parachute Creek valley, occurs where air temperature increases with altitude,
holding surface air, along with the pollutants it contains, down.
Grand Junction 700 millibar wind data at approximately 10,000 feet are believed to
closely represent the 700 millibar winds over the project area. The data show that
the wind direction varies from the west to southwest. These winds, when exhibited
near the surface, turn to the left and blow from a more southerly direction due to
effects related to friction with the surface. The Piceance Creek valley is oriented
along the northeast (down-valley) and southwest (up-valley) axis in the vicinity of
the Piceance Site. Thus, the prevailing synoptic-level wind direction is from the
southwest, with locally driven up-valley and down-valley flows also influencing
observed wind directions. Wind data taken at the Cb oil shale tract Site 023 and
presented as wind roses in Figure 7-16 show that the greatest frequency of wind, 100
feet from the surface on top of a plateau, is from the south southwest.
7.5.2 Air Quality
The Piceance Creek Basin and Parachute Creek valley are Class II air quality area, as
are most regions of the state. Class II areas have specified allowable increases
(increments) of pollutants that may never exceed a given standard (ambient
standard). Class I areas, which have more stringent air quality standards, are located
in the region. These include the Flat Tops and Mount Zirkel Wilderness Areas
(closest at 41 miles and 89 miles, respectively, and downwind relative to
predominant wind directions) and the Maroon Bells, West Elk, and Ragged
Wilderness Areas (more distant and less downwind).
American Soda, L.L.P. '7_2C~
Commercial Mine Plan
August 18, 19918