Laserfiche WebLink
<br />Memo to Tony Waldron <br />Bowie No. 2 Geotechnical Adequacy <br />page 2 <br />2.05,6 Mitigation of the Imaacts of Mining Oaerations <br />2,05.616) Subsidence Survey, Subsidence Monitoring and <br />Subsidence Control Plan <br />Many of the detailed comments included within the following discussion of Exhibit 15 <br />also apply to the general statements included by the preparer within section 2.05.6(6) of <br />the permit application text. To avoid duplication the more specific comments have been <br />included within the detailed discussion of Exhibit 15. Appropriate changes to the permit <br />application text section will be necessary after Division concerns regarding Exhibit 15 <br />have been resolved, <br />(bl(I-(cl <br />The Division considers stock watering ponds to be manmade structures, rather than <br />renewable resource lands. <br />The position of the applicant presented throughout the application is that no significant <br />water resources exist within the overburden or on the surface of the permit area. The <br />Division's experience in the North Fork Valley suggests that many of the perennial springs <br />and all surface runoff is appropriated. Potential disruption of any of the water sources <br />requires a plan for augmentation approved by the water court. <br />As discussed under other geotechnical topics, the Division believes the existence of <br />historic and modern landslides within the permit area constitutes a significant <br />geotechnical concern for the proposed Bowie #2 mine's operation and reclamation plan. <br />The preparer is correct in observing that no specific criteria are available for the <br />delineation of specific subsidence-related landslide hazard increase. This topic is better <br />addressed under the specific sections relating to stability of the operating facilities, such <br />as roads and portal benches, and the reclamation plan. However, the Division does <br />believe it would be appropriate to visually inspect known historic and modern landslides, <br />during the periods immediately following retreat extraction in their immediate proximity. <br />(f11ii11B) <br />The application proposes a method to prevent near subcrop subsidence impacts, including <br />rhimney collapse and cantilever failure. However, the preparer of Exhibit 15 is <br />ambiguous in the important referenced section. The applicant should clarify the proposal. <br />Further, additional information should be provided to stipulate whether the extended pillar <br />will be unmined, or developed. Obviously, at least one development room will have been <br />