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-3- If the applicant were to submit an acceptable certified schedule and obtain approval of the "general plan" for the proposed coal processing waste structure, the Division could then stipulate the completion of the "detailed engineering design" for that structure. However, in any case, that detailed engineering design would have to be approved before the applicant began mining coal. This means that approval would need to be completed, according to the amended letter schedule, prior to the 4th Quarter of 1985. In my earlier review of the applicant's first response letter I also mentioned an alternative. The applicant could pursue phased approval of the coal processing waste embankment structure. However, by "phased approval of the ... structure", I meant approval of a pile to be built in phases. I envisioned a small initial pile with a lower facial slope angle, which could easily be demonstrated to achieve the appropriate seismic slope safety factor. As I indicated in that earlier review; "In order to pursue this approach, the application would have to be amended to include appropriate stability analyses for each of the separate phases' configurations, such as that of the starter embankment." I did not envision the phased approach to include deferring the approval and construction of the entire waste embankment to some distant point in the future. As I also indicated in my review of the applicant's first response letter, the applicant had responded to our comments contained within our original adequacy review, which dealt with deficiencies contained in Appendix 3.3-3a. The amendments were made in the form of amended pages to the original consultant's report, prepared by Chen and Associates, Inc. However, nothing was submitted in those supplemental submittals to attest that the report, as amended, was still certified by Chen and Associates, Inc. I requested that the applicant submit a certification statement, prepared by Chen and Associates, certifying the consultant's authorship of the report amendments. That certification statement has yet to be submitted by the applicant or Chen & Associates. The applicant's response letter indicates that they will submit the certification during Phase B of the mine plan. If the report is not certified, the Division will have to require its removal from the permit document. Without the supporting Exhibits originally prepared by Chen & Associates, the Division cannot find conformance with any of the regulatory requirements concerning geotechnical investigation or stability analyses. The "general plan" would not then be approvable. In my first response review, I indicated a number of deficiencies which required resolution, summarized as follows: (1) The applicant performed a pseudo-static seismic stability analysis of the proposed life-of-mine configuration for the 300' high coal processing waste slurry embankment. The applicant has applied a horizontal acceleration factor of 0.1, as recommended by Mr. Rahe Junge of the Colorado Geological Survey. Unfortunately, the analysis performed determined the pseudo-static slope stability safety factor of the life-of-mine structure to be l.l. Rule 4.11.5(3)(a)(ii) specifically requires that the seismic safety factor for such structures "be at least 1.2". The applicant will have to amend the engineered design, in order to achieve the required seismic safety factor.