GENERAL31880 - Laserfiche WebLink

Home Browse Search

c • • Mr. John Walters - 3 - October 4, 1985 Salt Creek Mining Company has accepted the success standard as proposed by the Division. A statement to this effect is provided on revised Page 3-16 of the permit application. Stipulation No. 9, attached to Permit No. C-004-80, is therefore considered resolved. Stipulation No. 10 WITHIN SIXTY (60) DAYS OF PERMIT ISSUANCE, THE PERMITTEE SHALL REVISE THE PERMIT APPLICATION TO INCLUDE THE ANNUAL REVEGETATION MONITORING PROGRAM PROPOSED FOR THE MUNGER CANYON MINE IN THE APRIL 18, 1983 LETTER TO THE DIVISION FROh1 SHERIDAN ENTERPRISES. THE PROGRAM SHALL BE INITIATED THE SECOND YEAR AFTER INITIAL PERMANENT REVEGETATION SEEDING OF ANY AREA AT THE McCLANE CANYON MINE. Salt Creek Mining Company has submitted an acceptable monitoring plan to the Division. For clarity, it is noted that the permittee need implement the monitoring only in years 2-8 of the extended liability period. In years 9 and 10, a full scale sampling program will be required prior to application for bond release. Stipulation No. 10, attached to Permit No. C-004-80, is considered resolved. Stipulation No. 11 WITHIN SIXTY (60) DAYS OF PERMIT ISSUANCE, THE APPLICANT SHALL REVISE THE PERMIT APPLICATION TO COMMIT TO BACKFILLING THE PORTAL FACE-UP AREA TO THE ORIGINAL "STRAND LINE" OR CREST LINE OF THE ORIGINAL UNDISTURBED SLOPE WHICH WAS EXCAVATED OUT DURING CONSTRUCTION OF THE MINE BENCH AND PORTALS. THE SLOPE GRADIENT AND COMPACTION OF THE BACKFILLED PORTAL FACE-UP AREA SHALL BE DESIGNED TO ACHIEVE A MINIMUM STATIC SLOPE SAFETY FACTOR OF 1.3. COMMITMENT BY THE APPLICANT TO THIS BACKFILLED CONFIGURATION SHALL NOT PRECLUDE THE APPLICANT FROM SUBMITTING A FUTURE REQUEST TO THE DIVISION FOR REVIEW AND APPROVAL OF AN ALTERNATIVE BACKFILLING SCHEME FOR THE PORTAL FACE-UP AREA WHICH WILL MEET THE REQUIREMENTS OF RULE 4.14.2. Salt Creek Mining had a pre-mining topographic map prepared for the surface facility area, utilizing a pair of U.S.G.S. stereographic aerial photographs taken in 1967. That map demonstrates that the area does qualify as a "steep slope mining area", in compliance with the definitions in Rule 1.4(125) and 2.06.4. The pre-mining slopes vary from 39 to 43 degrees from horizontal. Because of the stability problems associated with the reclamation of slopes of that steep gradient, the Company properly requested a variance from approximate original contour for the mine bench and portal area. The Company has included comparative slope stability analyses of the pre-mining and post-mining slopes for the steepest reclaimed slope within the portal and mine bench area. This analysis demonstrates that the proposed reclaimed slope configurations would improve the slope stability of that area from 1.234 for the pre-mined slope to 1.311 for the proposed reclaimed post-mining configuration. The Company commits to the backfilling of all exposed coal outcrops, except in the area of the two deeply incised natural stream channels, in which pre-mining coal outcrops existed.