_GENERAL DOCUMENTS - C1981017 ‎(279)‎

• Permit No: C1981017
• IBM Index Class Name: GENERAL DOCUMENTS
• Doc Name: Bid Documents ‎(IMP)‎
• Media Type: D
• Archive: No

�pF COS DEPARTMENT OF NATURAL RESOURCES
(�Q 9� D Monte Pascoe,Executive Director
* 10 4- MINED LAND RECLAMATION DIVISION
DAVID C.SHELTON Director
1876
Richard D Lamm
Governor March 17, 1982
TO: Jim Herron
�V
FROM: Dave Crai g �
RE: Mid-Continent Ground Water Findings
Coal Basin Mines
I. Description of Existing Environment
Ground water occurs in both bedrock and alluvial aquifers in the vicinity of the
Mid-Continent mining operations. Bedrock strata which have the potential to be
labeled aquifers are the Upper Sandstone, the Middle Sadnstone and the Rollins
Sandstone, all of the Mesa Verde Group (see Figure III-D-1 of the permit application) .
The alluvial deposits of Coal Creek also can be labeled an aquifer. The only known
users of ground water in Coal Basin have all completed wells in the alluvial
aquifer of Coal Creek (see Table III-C-3 of the permit application) . There are
no known users of bedrock ground water from the Mesa Verde Group in the vicinity
of the mine. Many of the other strata are water-bearing, but yield insufficient
quantities of water to be labeled aquifers.
As stated earlier, 3 sandstone units in the Mesa Verde Group have the potential
to be labeled aquifers. In the Coal Basin affected area, the Upper Sadnstone is
approximately 50 feet thick, the Middle Sandstone is about 120 feet thick, and
the Rollins Sandstone is about 140 feet thick. To better understand the
strati graphic relationships between these sandstones and the coal seams being
mined, see Figure II-D-1 of the permit application. Generally, the Rollins Sand-
stone immediately underlies the "B" seam and the Middle Sandstone immediately
underlies the "V" seam. All of these sandstone units outcrop on the eastern wall
of Coal Basin (See Map III-C-1 of the Permit application) . This is where recharge
to the aquifers probably occur. From the outcrop, the sandstones dip to the west
under Huntsman Ridge, and eventually, deep under the Piceance Basin. On the
western side of Huntsman Ridge, the sandstones are located about 2000-3000 feet
beneath the surface (see Plate II of the permit application) . There are no known
users of this ground water primarily because of this great depth. The water yields
that could be expected from these sandstones are too small to justify the great
cost of drilling to this depth. Also, because of this great depth, no site-
specific data has been collected regarding the hydraulic characteristics or water
quality of these potential aquifers. However, the applicant estimates that
permeabilities in the sandstone aquifers range from 10-2 to 1 foot per day with
transmissivities ranging from 0.5 to 150 ft2 per day. During a USGS survey, only
one well was located in the Mesa Verde Group in the vicinity of the mine. It is
not known specifically what strati graphic unit this well is completed in. However,
the water quality of this well was reported to be a calcium bicarbonate type with a
total dissolved solids concentration of 181 mg/l.
423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203 Tel. [phone]