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page 3 Memo to Susan Mowry Animas Mine Waste Pile T.R. originally permitted surface facilities. The applicant would prefer to construct the facial slopes of this early portion of the pile to conform with the steeper amended configuration of the pile, in an effort to avoid reconstruction following requested approval of the amendment. The applicant also proposes to enlarge the pile from 16.0 to 29.8 acres. This expansion would include areas undermined by previous workings of the Animas Mine and earlier operations. This particular areas of the underground workings of the Animas Mine (formerly Helen Mire) involved have been temporarily abandoned due to poor roof conditions. The applicant recognizes that Rule 2.05.3(8)(a)(i)(D) requires the completion of a specific analysis of the potential impacts of subsidence upon the proposed amended pile. However, that analysis is not included within the technical revision application. The undermining does not underlie areas of the originally approved coal processing waste pile. Rule 2.05.3(8)(a)(i)(D) requires that any application for approval or revision of a coal processing waste pile which overlies existing underground mine workings must contain a general plan which contains, as stated within that. Rule, "...a survey describing the potential effect on the structure from subsidence of the subsurface strata resulting from past underground mining activities..." In response to our earlier completeness comments regarding this concern, the applicant has amended the Technical revision application by letter to state: "The specific subsidence analysis cannot be performed at this time until mine projections (with or without retreat mining) have been determined. The mine is currently gathering exploration data to aid in these decisions. The area of old workings is located such that refuse placement can occur for years without depositing material in any area affected by old workiRga. It is therefore requested that refuse be placed only in the area delineated on the enclosed map until mining projections have been determined and the surface subsidence can be accurately evaluated." In light of the applicant's cosunitments to perform the required sophisticated mathematical stability analysis of the proposed pile amendment, to restrict deposition of coal processing waste to the two lower-moat 50 foot thick terrace benches of the proposed pile, to restrict deposition to the reduced area delineated upon the supplemental map, and to redesign and reconstruct the pile slopes, if necessary, I deem it appropriate to approve the company's application with the following stipulations: Stipulation ~kl: THE DIVISION DIRECTS SUNDANCE COAL COMPANY TO COMPLETE A SITE-SPECIFIC SOPHISTICATED MATHEMATICAL STABILITY ANALYSIS OF THE AMENDED CONFIGURATION PROPOSED FOR THE COAL PROCESSING WASTE PILE AT THE ANIMAS UNDERGROUND COAL MINE. SUNDANCE COAL COMPANY SHALL SUBMIT THAT