GENERAL31006

• Permit No: C1981044
• IBM Index Class Name: General Documents
• Doc Date: 6/6/1984
• Doc Name: ADEQUACY REVIEW OF EAGLE 5 MINE PROPOSED UTAH TRACT EXTENSION
• From: MLRD
• To: SANDY EMRICH
• Permit Index Doc Type: GENERAL CORRESPONDENCE
• Media Type: D
• Archive: No

Richard D. Lamm
Governor
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DEPARTMENT OF NATURAL RESOURCES
Davitl H. Getches, Executive Director
MINED LAND RECLAMATION DIVISION
DAVID C. SHELTON, Dlractor
DATE: June 6, 1984
T0: Sandy Emrich
FROM: Joe Oliver ~'~ - ~<~
RE: Ade uac ReJ~ii'w of Ea le No. 5 Mine Pro o ed Utah T ~ t t n '
q y 9 p s rac Ex a ston
Per your request, I have completed an adequacy review of the geology, ground
water resources, and surface water resources sections of Empire Energy
Corporation's permit revision application, which was deemed complete on
April 9, 1984. The following are adequacy concerns raised during the review,
organized according to the subtitle disciplines as they would appear in the
findings document.
V. Geology - Rules 2.04.5 and 2.04.6(2
1. The proposed revision to the mining plan calls for an extension of mining
in the No. 5 Mine into the Utah Tract area, which is a 427 acre tract that
includes acreage previously mined and reclaimed by Trapper Miming, Inc. The
applicant predicts that maximum vertical subsidence will be between 5.5 and
8.0 over the undermined areas. With the occurrence of this mztgnitude of
subsidence in unconsolidated backfilled spoil material with ttie surface at
fairly steep slopes (up to 20 degrees) and bedrock dip slopes of 7 to 10
degrees, the Division (and the applicant) must consider the possibility of
subsidence-induced landslides in this area. Previous experience with
landslides in reclaimed mine spoils dictates the need for certain types of
information in order to more fully understand the nature of any landslide, if
it were to occur. Therefore, the Division requests that the applicant submit,
for inclusion in the permit revision application, a map of the: Utah Tract and
adjacent areas, depicting the precise location of all surface mine highwalls,
sufficient to define the pit design to at least 1,000 feet outside of the
predicted angle of draw boundary. The pit depth (or thickness; of backfilled
spoils) should also be depicted on the map. This map must al<.:o contain
locations of all faults, joint sets, zones of bedding plane weakness, or other
geologic structures that have been identified within this area. The requested
information may be included on an existing map within the permit application,
but if a new map is submitted, it should be at the same scale (1"-400') as the
other mine plan maps.
423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203 Tel. [phone]