GENERAL53077

• Permit No: C1981041
• IBM Index Class Name: General Documents
• Doc Date: 12/1/1982
• Doc Name: Proposed Decision and Findings of Compliance
• Permit Index Doc Type: FINDINGS
• Media Type: D
• Archive: No

-IS-
•
VI. Ground Water Rydrology (cont'd)
or fractures and faults. However; it is evident that the mine is having an
insignificant effect on the quantity of water in the Colorado River system as
long as mine inflows are-pumped out of the mine.
The major effect of mining on the quality of water is through an increase in soluble
salt levels. There is a slight increase in the pH of the inflow water over that of
the Colorado River water, but this effect is insignificant. Because of the pH of
the water, heavy metals would be relatively insoluble. Thus, they should pose no
significant problem to water quality.
The mine discharge water has a higher rnntent of soluble salts than the Colorado
River. Discharge from the mine is diluted by receiving waters, which results
in a total increase in the soluble salt level of the Colorado River by an average
of 0.1~. This is the current estimate but will be revised as new information becomes
available as a result of NPDES requirements.
The underground disposal of coal processing waste at the Roadside mine should have
an insignificant effect on ground water. The material being backstowed in the mine
is similar to material presently exposed in the mine. Although no pre-mining ground
water quality data is available, there should be little change in the water quality
attributable to the coal processing waste disposal. The water used to transport
the waste into the abandoned underground workings will be drained and reused. Thus,
this water will not affect any surface or ground water. A minimum of 20~ of the
water used in the backfilling operation will be retained by the waste according to
the applicant's calculation. Monitoring of water in the Rollins Sandstone, which is
the strata that potentially may be affected up-dip and down-dip of the disposal
areas, will verify the priojected ground water effects.
Another potential effect on ground water will take place during the backfilling and
grading operation. The applicant proposes to backfill the Cameo Decline and the
North Decline with coal processing waste. This is necessary to achieve approximate
original contour, since sufficient fill material is not available to completely
backfill the depressions. If coal processing waste was put in the bottom of the
declines, it would be in contact with ground water, since both declines are below
the level of the Colorado River. The applicant will be required to place non-toxic
material in the Declines to a level above the level of the ground water (e.g.,
level of the Colorado River). The decline will then be backfilled with coal
processing waste and finally the waste will be covered with four feet of the best
available non-toxic, non-combustible material. Since this backfilling will not occur
until after cessation of mining, a specific plan is not necessary at present. There-
fore, this will be covered by the following stipulation:
STIPULATION No. 2
SIX MONTHS PRIOR TO BACKFILLING THE CAMEO AND NORTH DECLINES, THE
PERMITTEE MUST SUBMIT A PLAN FOR DISPOSAL OF COAL PROCESSING WASTE
IN THE CAMEO AND NORTH DECLINES TO THE DIVISION FOR APPROVAL. THIS
PLAN MUST INCLUDE R DISCUSSION OF THE PROJECTED EFFECTS OF DISPOSAL
AND A RECLAMATION PLAN FOR THE DECLINES.
The applicant's proposed ground water monitoring plan is contained in Section 2.05.6
of Volume V. Monitoring of ground water is to include sampling of collection points
in the underground workings, sampling of monitoring wells drilled in association
with the underground waste disposal project, and sampling of reclaimed water from
the underground waste disposal sites. Sampling is to be done quarterly at all sites.
O.i