2016-12-23_PERMIT FILE - C1982056A ‎(8)‎

• Permit No: C1982056A
• IBM Index Class Name: Permit File
• Doc Date: 12/23/2016
• Section_Exhibit Name: 2.04 Environmental Resources
• Media Type: D
• Archive: Yes

AVF. Soil cores #2 and #9 were excavated to the groundwater table. The remaining upland soil cores were
excavated to a lithic contact or parent material and did not encounter any groundwater. On completion of soil
sampling activities, all sample holes were completely backfilled with soil material and backfilled soil materials
were tamped down and leveled at the natural ground surface.
Soil Descriptions:
Each soil core was described by horizon following accepted United States Department of Agriculture Natural
Resource Conservation Service (MRCS) soil survey procedures for the following parameters: horizon depth; field
texture; Munsell color (matrix and mottles); root presence and depth; soil structure; and depth of ground water
table. Additional soil descriptions were recorded as needed. Photographs were taken of each soil core after
characterization. Major soil horizons are marked with orange markers along a tape in each photograph. Field soil
descriptions for each soil core are contained in Exhibit 16C, Appendix 1. Photographs of the soil cores are
contained in Exhibit 16C, Appendix 2. NRCS soil series descriptions of the potentially affected soils are contained
in Exhibit 16C, Appendix 3.
Soil Mapping & Taxonomy
Preliminary soil maps from the unpublished NRCS Soil Survey for Routt County were reviewed prior to locating
soil mapping unit boundaries for the study area. Field descriptions from each of the 12 soil cores and additional
non -characterized cores were used to determine soil map unit boundaries (Maps 1 S and 2S of the soils report) and
soil taxonomy to the soil series or family level. Preliminary NRCS map unit descriptions of the Slocum loam,
Winevad-Splitro Complex, Claybum loam, Aaberg clay and Binco silty clay loam and their known inclusions were
used to determine the affected soil series (Exhibit 16C, Appendix 3). As with all floodplains in this area, flooding
and the deposition and erosion of material may be a frequent occurrence (100 year precipitation event). Frequent
flooding, channel movement, erosion and deposition have resulted in highly variable soil profiles within the
previously mapped AVF.
Results
The soil description field forms and photographs for each characterized soil core are contained in Exhibit 16C,
Appendix 1 and Appendix 2 respectively. The primary soil parameters including bottom depth of rooting, depth to
the top of mottling and depth to surface of the groundwater table are summarized in Table 2.04-1. NRCS soil series
descriptions are contained in Exhibit 16C, Appendix 3.
Table 2.04-1. Selected Observed Soil Core Parameters
Soil Core
#
Depth of Rooting
(inches)
Depth to Mottles
(inches)
Depth to Water
(inches)
1
23
na
Na
2
25
12
41
3
8
na
na
4
9
na
na
5
48
na
na
6
50
na
na
7
54+
na
na
8
40+
na
na
9
47
70
105
10
19
na
na
11
20
na
na'
12
20
na
na
Soil core #1 was characterized as a Winevada and soil cores # 3 and #4 as Splitro series within the Winevada-
Splitro complex, 3-25 percent slopes, map unit XBD. Soil core #2 was characterized as a Cumulic Cryaquoll and
soil core #9 was characterized as a Menbar series and both were mapped as inclusions within the Slocum loam
variant, 0-5 percent slopes, map unit 56A. Soil cores #5 and 6 were characterized as within the Clayburn series, 3-
MR16-296 2.04-50.1 05/10/16