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Applicant's Response to Second Adequacy Letter Grand River Park Project, DRMS File M-2006-046 January 2, 2007 Page 5 is capable of self-regeneration without continued dependence on irrigation, soil amendments or fertilizer..." The applicant and Division have noted that, despite the broad soil classifications applied to the site by USDA mapping, the topsoil horizon across a significant extent of the site has apparently been affected by borrow operations, presumably fill removal to create the floodway levee and road embankment for adjacent Interstate road improvements. Parts of the site have exposed gravel pockets, yet depletion of the indigenous topsoil layer by borrow operations has not prevented those areas from also being vegetatively productive, including harboring some of the mapped wetlands on the site. The benchmark for Rule 3.1.10(1) is the capability of reclaimed soils to be productive in relation to surroundings. Existing conditions at the site clearly demonstrate that 30 inches as a minimum topsoil requirement is: unnecessary to support self-regenerating vegetation; excessive, given the inherent nutritive soil characteristics in an alluvial floodplain, and, especially given the Division's previous adequacy review requesting a six inch topsoil layer at reclamation, arbitrary. The applicant also notes that Rule 3.1.9 ("Topsoiling") provides no basis for the prescription of topsoil depths based on identification of USDA soil mapping units as an existing condition. Rather, the details of a reclamation plan "shall be appropriate to the type of reclamation necessary to achieve the proposed postmining land use" (C. R.S. § 34-32.5-116(2)). Referencing the applicable statutes and Rules, the applicant submits that soil conditions in the proposed reclamation plan will, in terms of the vegetative matrix, be productive and self-regenerating, and will specifically conform to quantitative topsoil depth requirements for recreational facilities in accordance with best practices and standard specifications. (At this time, a passive recreational facility or wildlife park is envisioned as the specific post-mining land use.) Responding to the options presented by the Division in its adequacy comment, the applicant believes the option most consistent with the Rules and the intent to create a viable, productive vegetative cover is to provide detailed specifications that will ensure appropriate nutritive values in the reclaimed topsoil horizon. As alluded to in the previous adequacy response, the applicant believes that topsoil resources across the entire site may be sufficient to provide asix-inch minimum plant growth medium on all reclaimed surfaces above normal water level; given the applicant and the Division's mutual goal of ensuring a versatile and robust plant growth medium, the applicant is firmly committed to providing the six inch layer initially requested and unconditionally states its commitment to providing six inches of topsoil as initially specified by the Division. To further address nutritive capability of the plant growth medium, in accordance with the most recent adequacy review, the applicant commits to a comprehensive soil amendment and seedbed preparation program. This program will consist of initial application of 250 lbs./acre of 18-46-0 fertilizer (diammonium phosphate)