2010-05-07_PERMIT FILE - C2009087 (8)

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RULE 2 - PERMITS Bss horizon — four to 15 inches; brown (10YR 4/3) clay (45 percent clay), dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; hard, firm, sticky and plastic • consistence; common to few medium, fine, and very fine, and few coarse roots; slightly effervescent; from lab data: pH =6.0 (moderately acid), EC =0.1 (nonsaline), SAR =0.6 (nonsodic), OM =1.4 percent; gradual wavy boundary. BC horizon — 15 to 26 inches; yellowish brown (10YR 5/4) clay (46 percent clay), dark yellowish brown (10YR 4/4) moist; massive structure; very hard, very firm, sticky and plastic consistence; slightly effervescent; from lab data: pH =6.2 (slightly acid), EC =0.3 (nonsaline), SAR =1.7 (nonsodic); OM--0.6 percent, gradual wavy boundary. C horizon — 26 to 38 inches; yellowish brown (IOYR 5/4) clay (45 percent clay), dark yellowish brown (10YR 4/4) moist; massive structure; very hard, very firm, sticky and plastic consistence; slightly effervescent; from lab data: pH =6.9 (neutral), EC--0.2 (nonsaline), SAR =1.7 (nonsodic), OM =0.5 percent; gradual wavy boundary. Ck horizon - 38 to 54 plus inches; light yellowish brown (10YR 6/4) clay (47 percent clay), yellowish brown (10YR 4/4) moist; white carbonate streaks and spots; massive structure; very hard, very firm, sticky and plastic consistence; moderately to strongly effervescent; from lab data: pH =7.8 (slightly alkaline), EC =0.3 (nonsaline), SAR =2.3 (nonsodic), OM--0.5 percent; gradual wavy boundary; auger refusal at 54 inches — clay too hard and too dry to dig further down. Man Unit 35E: Aaberg silty clay, 20 to 40 percent slopes • Aaberg was recently re- correlated to the Phippsberg soil series but the Aaberg name is retained for potential surface - affected areas within the permit area because it is part of both the Seneca II Mine and Foidel Creek Mine soil legends. The Phippsberg name is used for non - affected areas. Aaberg is an established soil series of moderate extent mapped in the mountainous areas and valleys of north- central Colorado, and is classified as a "Fine, smectitic frigid Leptic Udic Haplustert". Diagnostic features for the typical pedon include a `Bss" horizon (`B" horizon with slickensides) from seven to 37 inches in depth. The most recent official NRCS soil series description for Aaberg, dated January 2006, is on file. Phippsberg is essentially the same soil as Aaberg except it is considered to have an "ustic" soil moisture regime with 18 to 26 inches of average annual precipitation rather than about 12 inches for Aaberg. Phippsberg is classified as a "Fine, smectitic Chromic Haplocryert". Aaberg Typical Sample "CC -3" Site and Profile Description: Aaberg clay was fully described and sampled at one representative site, CC -3, located near the SE corner of Section 11, TSN., R87W. The sample site is on an upland ridge sideslope with big sagebrush and mixed grass vegetation, and is within the previous potential transportation corridor in the hilly ridge "gap" area between the south end of the Seneca II Mine permit area and the north end of Foidel Creek Mine permit area. Sample site CC -3 has 12 percent slope, south aspect, slopewash alluvium over residuum from clay shale; and stable surface with no erosion in the vicinity of the sample site location. An evaluation of soil suitability indicates the sampled Aaberg pedon CC -3 is consistent with the previous Seneca II Mine recommended topsoil salvage depth of 6 to 8 inches, with an average recommended depth of seven inches. Clay content is too high ( >40 percent) below seven • inches for salvage. PSCM Permit App. 2.04 -129 6/15/09