Laserfiche WebLink
Gary Isaac <br />CAM-Colorado, LLC <br />August 29, 2008 Page 22 <br />56. In the soil suitability and salvage recommendation section of Exhibit 7, for Map Unit E <br />(the major portion of the coal waste area footprint), narrative notes that the Chipeta soil <br />makes up approximately 40% of the unit, with the remainder of the unit comprised of <br />"raw Mancos Shale Badlands". The narrative further notes that the badlands portion of <br />the unit has no soil and is not recommended for salvage, and that, in practice, "the <br />salvage operator will have to distinguish between the raw Mancos Shale Badlands and <br />the weathered Chipeta soil in order to only salvage Chipeta and avoid the clay badlands". <br />Our understanding of the coal waste pile soil and coverfill handling plan, and calculated <br />soil volumes, is that the 6" upper lift (topsoil) from the Chipeta soil within Unit E would <br />be separately salvaged and stockpiled in Topsoil Stockpile 1 (avoiding the "raw Mancos <br />Shale Badlands" portions of the Map Unit). However, regarding subsoil salvage, <br />approximately 1/4 of the material volume placed on the coverfill pile for eventual <br />replacement as the "bottom coversoil layer" on the flat top of the pile would be Chipeta <br />subsoil, while essentially all of the remainder (mixed in with Chipeta subsoil during <br />handling) would be "raw Mancos Shale". Further, essentially all of the coal waste pile <br />founding material to be contemporaneously placed as coverfill on the completed benches <br />and slopes of the waste pile would be Mancos Shale. <br />Please confirm if our understanding of the plan as presented is correct. Given the site <br />location chosen for the coal waste disposal area, and the very limited soil resources <br />available in the vicinity, we realize that the consultant's recommendation to "avoid the <br />clay badlands" (Mancos), with respect to subsoil salvage was not practicable. We further <br />realize that the site location chosen was due in part to concerns expressed by the Division <br />of Wildlife; their strong recommendation being that disturbances should be minimized on <br />the sagebrush benches important for deer and elk winter range, and concentrated to the <br />extent possible on the less productive salt desert and clay badland sites. <br />Although the pile location may be the best available, the relatively steep final slopes of <br />the pile, combined with the and site conditions and Mancos subsoil with a topsoil layer <br />less than 4" thick will present a very difficult revegetation challenge. It may be necessary <br />to develop a specialized seedmix for use on the site, along with possible use of soil <br />organic amendments, subsoil scarification, surface mulch, and possibly other treatments, <br />to enhance potential for establishment of a perennial vegetation cover comparable to <br />adjacent areas with similar soil characteristics. Installation of field trial vegetation plots <br />to mimic final waste pile slope conditions, for the evaluation of alternative seeding and <br />cultural treatments may be appropriate. Please take these issues into consideration, <br />address the concerns in the response to this letter, and propose such revision to the <br />reclamation plan as you believe to be warranted. Approaches based on documented <br />research or case studies involving revegetation of comparable sites (Mancos shale or <br />Mancos derived soils or comparable heavy textured substrate with similar chemical <br />characteristics, 9" precipitation zone, 3:1 or steeper slopes, etc.) should be considered.