2022-06-13_PERMIT FILE - C1980007 ‎(2)‎

• Permit No: C1980007
• IBM Index Class Name: Permit File
• Doc Date: 6/13/2022
• Doc Name: 2.04-115 Thru 2.04-125
• Section_Exhibit Name: 2.04.8 Climatological Information
• Media Type: D
• Archive: No

West Elk Mine

2.04-118 Rev. 08/94- TR71, 06/95- PR06, 03/06- PR10;05/22- MR462
have received over the years. April, May, September, November, and December always received at
least 0.1 inches precipitation on one or more days during the month. April, June, July, September,
October, November, and December have each had 1.0 inch or more precipitation on one day of that
month. Comparing this summary with the information on years before 1957 reveals no consistency
(Colorado Climatologist, Department of Atmospheric Sciences CSU).

Horse Creek Precipitation Station

A precipitation storage gage was installed near Horse Creek on the south of the mine site. Monthly
readings were recorded for several years at this station since June of 1977, weather permitting. The
gage was destroyed during floods in late May, 1983. A new gage was installed at a nearby location
on September 8, 1983. Monthly readings of precipitation for this station were reported in past
Quarterly Hydrology Reports for the West Elk Mine.

Site Specific Conditions

For purposes of this section, Spring is defined as March 1 through May 31 and Summer as June 1
through August 31. Analytical presentations and discussions are included to define the
meteorological characteristics of the West Elk Mine.

Site Description

The monitoring program for site specific information included three stations, identified as Site 1, 2,
and 3, located in the immediate area of the mine. Figure 12 shows the location of each monitoring
site. Site 1 was situated at an elevation of approximately 1,885 m (6,086 ft) above mean sea level
(MSL) immediately adjacent to the river and just east and upstream from the mine facilities
location. Site 2 was located approximately 260 m (853 ft) southwest of Site 1 at an elevation of
approximately 1,908 m (6,260 ft) above MSL. Site 3 was located approximately 945 m (3,100 ft)
southwest of Site 1 and further up the side of the river valley canyon at an elevation of
approximately 2,038 m (6,687 ft) above MSL.

Several parameters were measured at each site. Wind speed, wind direction, and ambient air
temperature were measured at all three sites. Equipment at Site 2 also recorded relative humidity
and precipitation. Recovered data were defined as data that passed quality assurance and review as
being valid reportable data. The following information summarizes the recovered and reported data
as percentages of total possible data quantities for the report period. Any missing data were
primarily due to instrument malfunctions.