2010-11-30_APPLICATION CORRESPONDENCE - C2010088 (2)

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Corey Heaps CAM - Colorado, LLC November 30, 2010 Page 9 23. Data from the three soil sample sites indicates that the surface 18" of the Billings soil at Sample #1 is a considerably better growth medium (lower pH, and much lower EC and SAR), as compared to the other two sample sites for the same soil unit. In fact, the soil horizon between 6" and 18" depth at Site I appears to be better quality growth medium than the surface 6" at Sample Sites #2 and #3. The soil salvage plan appears to be based on the characteristics of the soil at Sample Sites #2 and #3. Are Sites #2 and #3 believed to be more characteristic of the Billings soil areas that would be disturbed by site construction than Site #1? To what extent would map unit boundaries and interpretations be different if the Web Soil Survey map units were the basis of the mapping rather than the previous NRCS survey map (e.g. would Site #1 likely fall within a separate map unit and be subject to a different salvage plan than Site #2 and #3)? Please address these questions and discuss how the salvage plan proposed or amended will maximize salvage of the best quality soil materials, to ensure the best opportunity for successful vegetation establishment. 24. A significant portion of the area to be affected has been previously disturbed by Industrial activity, and the surface materials present in these areas are dominated by industrial wastes that are essentially barren of vegetation. There are generalized references to possible importation of cover material from outside the permit area to serve as a growth medium within the previously disturbed areas, since the surface materials within the areas of previous disturbance support little or no vegetative growth. Although given the circumstances, the imported material would not meet the specific regulatory definition of topsoil substitute, at least a portion of the material would function as such (additional material placed over the industrial waste and beneath the surface growth medium would function as subsoil, or non -toxic cover). Detailed plans regarding the source, quantity, and replacement thickness of proposed topsoil and non -toxic cover soil will need to be provided, along with the information required by Rule 4.06.2(a), to demonstrate the acceptable quality of such material as a plant growth medium. Plans for storage and stabilization of such materials on the permit area will also need to be included. Please address the use of imported topsoil and cover material for use in reclamation of the previously disturbed industrial land use areas, pursuant to Rule 2.04.9(3). Rule 2.04. 10 Vegetation Information 25. Rule 2.04.10(2) requires that the proposed reference area location be delineated on the Vegetation Map. The map legend specifies a green dashed line as the Greasewood Reference Area boundary. This line is shown along the western boundary. However, along the north end of the reference area, the apparent boundary is depicted by a black "vegetation type boundary" line, and along the eastern and southern sides of the area, the apparent boundary is depicted by a non dashed green line that continues along the western edge of the Reed Wash riparian corridor to the southern boundary of the permit area and beyond. Please revise the map to clearly mark the reference area boundaries, consistent with the map legend symbol.