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

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Corey Heaps CAM - Colorado, LLC November 30, 2010 Page 8 Rule 2.04.9 Soils Resource Information 21. It appears that a 1978 NRCS soil survey was used as the base map for the Exhibit 7 baseline soil survey, rather than the current NRCS soil survey for the Mesa County Area, as provided in the USDA Web Soil Survey. Based on the Web Soil Survey mapping for the area of the proposed permit, the dominant soil type within the native greasewood community is Skumpah Silt Loam 0 -2% slopes, with a small acreage of Sagers Silty Clay Loam Saline 0 -2% slopes located along the northwest boundary of the previously disturbed area, to the east of Reed Wash. A significant portion of the irrigated runoff wetlands between Reed Wash and Loma Drain are mapped as Cojam Loam 0-2% slopes on the Web Soil Survey mapping. These areas all appear to have been mapped as Billings Loam to Silty Clay Loam in the baseline soil survey (although there is some apparent disparity between map and text of the report with respect to the Irrigated Wetland areas). Narrow bands of Torrifluvents were mapped along the riparian area within the incised Reed Wash drainage (and apparently within the Loma Drain riparian zone as well, although this is not entirely clear from the report narrative). Please revise the Soils baseline map and report, as well as related narrative in Section 2.04.9, to reflect use of the current NRCS soil survey for initial map unit boundaries for the lands subject to the site specific baseline soil survey, or provide explanation and justification for use of the earlier NRCS survey as the basis for initial soil mapping. Similarly, for those lands within the permit area that were not subject to site specific baseline soil survey (lands not proposed for surface disturbance), please revise the map to reflect the current NRCS soil survey mapping, unless justification for use of the earlier NRCS soil survey can be provided. Please verify that the site specific baseline survey extended far enough to the west to include the margins of the Irrigated Wetlands vegetation type that would be crossed by the rail spur, and please delineate the boundary of the detailed baseline survey area on Map 6. 22. There is a Torrifluvents ( "RW ") map unit designation on the Soils Map (Map 6), within the northwest portion of the permit area within the Irrigated Wetlands vegetation type, but it is not clear whether the designation is intended to apply to a narrow corridor of presumed riparian vegetation along Loma Drain, or to the larger area of wetland vegetation. Please clarify and revise the map as appropriate, along with related text in the narrative of Section 2.04.9 and Exhibit 7. Note that the band of apparent riparian vegetation along Loma Drain as shown on the Vegetation Map (Map 3) does not correspond to the presumed riparian zone indicated on Map 6. Please explain the apparent discrepancy and revise whichever map is not correct. Also, please refer to concerns in Item 3 regarding the version of the NRCS soil survey used as the basis for the Exhibit 6 mapping. The current NRCS soil mapping (USDA Web Soil Survey) shows Ustifluvents, 0 to 2 percent slopes, occurring along the riparian zone within the incised Reed Wash drainage, rather than Torrifluvents.