GENERAL44216

• Permit No: C1981044
• IBM Index Class Name: General Documents
• Doc Date: 12/11/2001
• Doc Name: Page 33 through OSM Mine Plan Approval
• Permit Index Doc Type: Other Permits
• Media Type: D
• Archive: No

• the fault connections that previously allowed inflow from and an impact on the
quantity of water in the aquifer. The Middle sandstone, however, is not used•
for water supply in the area. The practical effects of these impacts are,
therefore, neglible.
No significant impacts are foreseen on any other bedrock aquifers by the Eagle
Mines. The adjacent Trapper Mine, however, does affect the quantity of water
available in the Twentymile sandstone which is used as a source of water for
that operation. This use does not impair the quality of water in the
aquifer. There is a potential impact of the Trapper Mine on the quality of
water in the lowest of the White sandstones by the eventually backfilling of
spoil material against the updip face of that sandstone. No lessening of
recharge to the White sandstone or of the quantity of water available results
from this practice.
The Eagle Mines have the potential to impact the quantity of water in the
Williams Fork alluvium. Discharge of degraded water into the alluvium from
the flooded No. 5 and No. 6 Mines following cessation of operations is
possible by means of the subcrops of the mined "E" and "F" seams in the
Williams Fork Valley. No impact of the Eagle Mines is anticipated on the
quantity of Williams Fork alluvial water or on either the quantity or quality
of water in the Yampa alluvium. There are no projected impacts of the Trapper
Mine on the water available from either the Williams Fork or Yampa alluvial
bodies.
• Such impacts as are made by the Eagle and Trapper Mines on the quantity and
quality of ground water in the basin are entirely separate. There are no
cumulative impacts on any individual bedrock or alluvial aquifer.
Cumulatively, however, the Eagle and Trapper Mines do reduce the overall
quantity of ground water available in the basin, and they cumulatively have
the potential to degrade the overall average quality of ground water in the
general area. The sum of the impacts of these mines, however, should not
significantly affect the use of ground water outside their permit areas. The
Division, therefore, finds that the proposed Eagle No. 5 and No. 6 Mines with
the stipultion made, have been designed to prevent material damage to the
hydrologic balance outside their permit area and to be in compliance with Rule
2.07.6(2)(C).
Surface Water
Permitted mines in the CHIS study area are listed in Table 1.
Salt loading predictions were calculated using surface water data from low
flow years and predictions of mining-related impacts: underground mine
inflows, spoils aquifer discharges, and outflows from flooded workings of
underground mines. It is difficult to classify the duration of these impacts
as many overlap. Mine inflows from Foidel Creek underground mine will
continue through 2015. (TABLE 2). Empire Energy's Eagle No. 5 and 6 Mine
will discharge until 2006. Backfilled spoils discharges take three to fifteen
years to develop and then are projected to discharge poor quality water for
several hundred years. Discharge from the flooded workings from Foidel Creek
• underground mine is not projected to begin until the year 2365. The discharge
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