GENERAL41305

• Permit No: C1980007
• IBM Index Class Name: General Documents
• Doc Date: 4/11/1986
• Doc Name: Proposed Decision & Findings of Compliance for PR3
• From: Permanent Lower Waste Pile
• Permit Index Doc Type: FINDINGS
• Media Type: D
• Archive: No

-51-
Water rights held by Western Slope Carbon are adequate to cover the
consumptive use in their mine operations (pages 2.04-29 to -33 of the
Hawk's Nest permit application). Western Slope Carbon estimates that
the Hawk's Nest Mine will consume 215 acre-feet of water per year,
which amounts to 0.0528 of the mean annual yield of the North Fork of
the Gunnison.
For WECC's Mt. Gunnison No. 1 Mine, the worst-case scenario would be if
the 150 acre-feet per year of water used foe spraying the coal and for
the potable water supply were entirely removed from the basin. On the
average, this would amount to approximately 12.5 acre-feet of water
each month. From Table 9, it appears (from Column 5) that the months
of August and September will be the critical months for removal of
water from the watershed. In reality, most of the water used for
potable water will be returned to the North Fork of the Gunnison
River. WECC's water is diverted from the North Fork to a storage pond
adjacent to the river. The total estimated worst-case depletion (150
acre-feet per year) would amount to only 0.048 of the mean annual yield
of the North Fork. (See materials submitted by WECC Coal Company,
December 15, 1981, in response to permit Stipulation No. 7.)
U.S. Steel Corporation has not submitted an estimate of the total water
consumption in the Somerset Mine. The Division, therefore, has made
the assu~tion that water consumption at the Somerset Mine is similar
to the proposed maximum water consumption in the Mt. Gunnison No. 1
Mine. This assumption is based on the close proximity of the mines,
the similarity in mining methods, coal handling, manpowec requirements,
and total annual coal production. This estimated water consumption
would amount to 150 acre-feet per year, or 0.048 of the mean annual
yield in the North Fork of the Gunnison.
The total estimated water consumed by all of the mines presently
operating in the North Fork Drainage Basin is 544 acre-feet per year.
This is approximately 0.13$ of the mean annual yield of the river.
This indicates that the total coal mining activities within the North
Fork of the Gunnison Drainage Basin have a very minor impact on the
quantity of water available in the Basin.
Cumulative Impacts of the Blue Ribbon and Somerset Mines
Since all previous mining at the Blue Ribbon Mine was within the
Hubbard Creek drainage basin, the most Significant cumulative impacts
of all mining will be the combined impacts of the Blue Ribbon Mine and
Somerset Mine on Hubbard Creek and on the downstream water users.
Data collected for the Somerset Mine estimates the annual yield in
Hubbard Creek to be 29,700 acre-feet per year (88 of the mean annual
yield of the North Fork of the Gunnison - 340,000 acre-feet per year).
The total depletion of the flow in Hubbard Creek due to the Somerset
Mine may be 0.07 cfs (31 gpm or 44,640 gpd) coming from inflow measured
in the Somerset Mine adjacent to or under Hubbard Creek. No further