GENERAL34573

• Permit No: C1981024
• IBM Index Class Name: General Documents
• Doc Date: 6/16/1983
• Doc Name: Proposed Decision and Findings of Compliance
• Permit Index Doc Type: FINDINGS
• Media Type: D
• Archive: No

20
The quality of ground water which flooded the old mine workings, has
become degraded over time. Ground water exposed to the coals and their
associated roof and floor strata has reacted with sulfide minerals and
leached soluble salts. These reactions within the old mine workings have
resulted in a shift from a sodium-calcium-bicarbonate type water with a
low total dissolved solids load to a sodium-sulfate type water with a
high total dissolved solids load. The following constituents are present
in the mine water at levels that exceed drinking water and/or
agricultural standards: Barium, Boron, Cadmium, Dissolved Iron, Lead,
I~anyanese, Sodium, Ammonium, Fluoride, Sulfate and Total Dissolved Solids
(see Table 6, Volume I of the application and Submittal dated September
30, 1982).
Degraded ground water flowing from these mine workings has contaminated
the hydrologically adjacent Trinidad sandstone and Alluvial aquifers.
Ground water quality decreases with depth and also from the east to the
west across the permit area as the water moves down the limb of the
syncline towards the center (Figure 7, Volume I).
The applicant is in the process of obtaining, from the Colorado
Department of Health, an approved plan for the treatment and disposition
of water pumped from old flooded workings. This plan will be required in
future permit applications involving dewatering of the old workings.
The surface mininy operation will impact six wells within and adjacent to
the permit area. A discussion of ground water depletion of wells is
contained in Section VIII, Water Rights and Replacement of this
documeni. All rights to these wells are now held by the applicant.
Water needs at the mine will be supplied by an industrial well. The
applicant will have an approved augmentation plan for use of water from
this well prior to its use.
It is anticipated that the proposed mining operation and future mining
may improve the quality of ground water in the area. The toxic Lennox
and Cameron coals will oe mined and the toxic roof and floor strata
associated with these coals will be backfilled above the ground water
table, thus removing a source of ground water pollution. A portion of
the old flooded workings would he destroyed and their ability to act as
conduits for polluted water and sites for leaching of soluble salts would
be greatly diminished. future pumping and subsequent treatment of
polluted ground water from the old mine workings also has a potential of
improving ground water quality.
Surface Water
Future mining plans entail the establishment of a 100 foot wide buffer
zone around the Gordon and f4aitland Arroyos, and the unnamed tributary.
This buffer zone will protect these drainages from any impacts from
mining.
Surface drainage will be controlled and treated in sediment ponds prior
to its release. No surface water resources are to be used at the mine.