2012-03-07_PERMIT FILE - C2010088 ‎(16)‎

• Permit No: C2010088
• IBM Index Class Name: Permit File
• Doc Date: 3/7/2012
• Doc Name: Soils Information
• Section_Exhibit Name: Exhibit 07
• Media Type: D
• Archive: No

recent air photo images, and the USGS 7.5' topographic quadrangle maps (Mack
Quadrangle). The previous soil boundaries were used during initial field reconnaissance
and observation, but were later revised. The entire area was traversed by vehicle on dirt
two-tracks where possible, and then elsewhere on foot. Soil map unit boundaries were
delineated by observing surface conditions, vegetation, slope gradient and aspect,
geology, and most importantly soil profiles exposed using a sharpshooter and bucket
auger. Dominant soils were fully described and sampled at representative sites primarily
in the proposed affected areas. The location of all soil sample sites was determined by
GPS and is shown on the project soil map.
The results of the soils field mapping, profile descriptions, and laboratory analysis were
used to evaluate topsoil suitability and generate soil salvage recommendations. The
evaluation generally followed parameters and threshold values contained in Table 1 -2
"Criteria to establish suitability of topsoil (or topsoil substitutes)" of Guideline No-1
'Topsoil and Overburden" (WDEQ, 1996). Unsuitability threshold values include: pH <5.0
or > 9.0, EC >12; SAR >15, or SAR >12 for soils with greater than 40% clay; Boron >5.0
ppm; coarse fragment content >35 %; saturation percent <25% or >80% (marginal rated);
Selenium >0.8 ppm (marginal rated); and sand, clay, or silty clay texture (marginal rated)
(WDEQ, 1996). The recommended salvage depths are discussed in the map unit
descriptions in the following results section. Topsoil volumes for salvaged soils are
included in the project reclamation plan.
The soil profile descriptions for all sampled soils include added information for each soil
horizon taken from the soils laboratory data. Soil reaction (pH), electrical conductivity
(EC), and sodicity (Sodium Adsorption Ratio, SAR) values are added to the profile
description so that the reader can see whether a particular soil, or individual horizons
within a soil, have low or high values concerning pH, EC, and SAR. A modifier phrase is
also added next to these values to indicate relative status, as follows.
For pH values, modifier terms are taken from a standard NRCS source (Soil Survey Staff,
1993) as follows: Ultra Acid ( <3.5), Extremely Acid (3.5-4.4), Very Strongly Acid (4.5 -5.0),
Strongly Acid (5.1 -5.5), Moderately Acid (5.6 -6.0), Slightly Acid (6.1 -6.5), Neutral (6.6-
7.3), Slightly Alkaline (7.4 -7.8), Moderately Alkaline (7.9 -8.4), Strongly Alkaline (8.5 -9.0),
and Very Strongly Alkaline ( >9.0).
For EC values, modifier terms are also taken from this standard NRCS source (Soil
Survey Staff, 1993) as follows: Non Saline (0 -2), Very Slightly Saline (2-4). Slightly Saline
(4-8), Moderately Saline (8 -16), and Strongly Saline ( >16).
For degrees of sodicity (SAR), modifier terms have been constructed based on a review
of recent NRCS material as well as well as experience with site - speck soils in the Big
Hom Basin, as follows: Non Sodic (0 -2), Slightly Sodic (2-8), Moderately Sodic (8 -15),
Highly Sodic (15 -30), and Very Highly Sodic ( >30).
3 Exhibit 7 — 2010 Train Loadout Soil Survey