2007-07-30_GENERAL DOCUMENTS - C1981041

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I The Colorado Water Quality Control Division was notified of the PR-3 application, and did not provide comments or concerns. (e) The applicant has demonstrated that the owner ofthe surface ofth~e lands within the permitarea has knowingly requested, in writing, as part of the application,l~that a variance be granted. Snowcap Coal Company, Inc., is the surface owner of the lands within the proposed AOC vaziance boundary (see Exhibit 6C). A letter of December, 13, 2006, included as permit application page A14-5-31 (Appendix 14-5 of the application), imm Nelson L. Kidder, Vice President of Snowcap Coal Company, Inc., satisfies this requiren~ient. f [~; (~ The applicant has demonstrated that the proposed operations will be conducted in compliance with the requirements of4.27.4. Please see findings pertinent to+Rule 4.27.4 below. ~^. (g) Based on a ~horough review ofthe application, the Division finds that all other requirements of the flct, these Rules, and the regulatory program will be met by the proposed operations. AOC Variance Findings Required by Rule 4.27.4 I'°, ~! Rule 4.27.4 allows a variance from the AOC requirements of Rule 4:27.3(3). Rule 4.27.3(3) also requires a demonstration that the minimum factor of safety for the stability of all portions of the reclaimed land is at least 1.3. To fulfill this requirement, SCC j~rovided a stability analysis demonstrating the proposed highwall backfill slopes and road fill' will meet the 1.3 safety factor requirement as discussed in 4.27.4(1) below. For the near vertical rocF;-cut slopes in the mine bench area, SCC provided a Professional Engineer certification in Appendix 14-10 ofthe application. The Division finds the certification that the steep rock slopes are environmentally sound and structurally stable, with a static factor ofsafety ofat least 1.3, to be adequate and acceptable, under the alternative specification provisions of Rule 4.27.3(8). I 4,27.4(1) requires that ...the highwall shall be completely bacl~lled wi!h spoil material, in a manner which results in a static factor ofsafety of at least 1.3 using standard geotechnical analyses. The application narrative notes on amended page 14-7, that the South Port31 area contains two potential highwalls, and further notes that "a highwall is the face ofexposed overburden and coal for entry into an underground mine". One ofthe highwalls referenced in the text is "an old ventilation entry along the portal access road", which was previously sealed and which gill be backfilled to AOC in conjunction withibackfilling and grading ofthe existing Access Road ``A" in that location. Since the old ventilation entry highwall will be backfilled to AOC, there is no sF~ecific finding required under Rule 4.27.4. The other highwall is the highwall associated with the two portal entries (intake and beltline) on the portal bench. This highwall is within the delineated A+9C variance area depicted on Exhibit 6C, and as such, demonstration of compliance with 4.27.4(]) is required. The portal entries highwall is delineated by a blue shaded area on 1?figure 14-t4. Based on site observation and map/photo comparisons, the Division concurs that tkie highwall is accurately and properly delineated on Figure 14-] 4. The blue shaded area which enc~impasses the steep northwest facing slope extending from the north side of the north (intake) portal,entry to the south side of the south (beltline) portal entry, and from the surface of the mine bench (approximate elevation 4840') to the crest ofthe cut slope over the mine entries (approximate elevation df4890'), comprises the "face ofexposed overburden and coal for entry into an underground mine" in this location. Permit narrative on amended page 14-7 describes the sequence of reclamation activity that will be Permit Revision No. 3 ~, Permit No. G 1981-041 July 30, 2007 i Page 42 .