Laserfiche WebLink
-33- <br />The soils which will be disturbed by the proposed operation include Billings <br />saline complex, Fruita sandy loam, Glendive loam, Havre loam, Nihill loam, <br />Rivra gravelly loam variant and Torriorthent rock outcrop complex. These <br />soils range from loam to sandy loam texture. Values for pH range from 7.2 to <br />9.0, with the higher value occurring below 33 inches in the Billings saline <br />complex. Sodium adsorption ratios (SAR) ranged from .2 to 57.3 with the <br />higher SAR in the Havre loam below a depth of 8 inches. Boron was measured <br />and ranges from .l to .7 mg/1. <br />Salt Creek Mining Company proposes stripping anywhere from 12 to 36 inches of <br />topsoil from disturbed areas, depending on the soil type encountered. The <br />steep slopes and thin nature of the Torriorthent soils will prohibit stripping <br />in some cases. No topsoil will be stripped from areas previously disturbed. <br />Table 4.4-8s of Volume VI of the permit application indicates that a total of <br />105.7 acre feet of topsoil will be salvaged from areas proposed for <br />disturbance along East Salt Creek under the proposed central facilities area <br />permit revision. Topsoil replacement operations will result in an average <br />soil replacement depth of 18 inches over regraded, non-agricultural areas. <br />Agricultural lands identified for disturbance (2.9 acres) will be retopsoiled <br />to a depth of 24 inches. <br />It is projected that approximately 6 acre-feet of topsoil will be stripped <br />from all areas to be disturbed within Munger Canyon. This volume will be <br />sufficient to replace topsoil over 12 to 18 acres of disturbance to a depth of <br />4 to 6 inches. This replacement depth will be sufficient to achieve <br />successful revegetation on the regraded areas. This determination is based <br />on an evaluation of the salvaged material as well as the surficial material <br />over which the topsoil will be respread. <br />A portion of the remaining disturbed area will be retained as a ranch road <br />which existed prior to the mine. In the areas where the road will be left, it <br />will be reduced in width and outslopes will be reclaimed. <br />A~portion of the mine bench will not be topsoiled. These areas consist of <br />fill which was used for grading the road and original ground. Prior to <br />issuance of the initial permanent regulatory program permit, the applicant <br />supplied analyses from grab samples of this material. Although these analyses <br />indicated that the material is suitable for reclamation, it was insufficient <br />for the determination of reclamation feasibility. A stipulation was <br />subsequently attached to the initial permit which required the applicant to <br />provide further analyses of the fill taken to a depth of 4 feet. The samples <br />taken in response to the stipulation were composite samples taken to a depth <br />of 4 feet. The analyses indicated slightly elevated SAR levels and an <br />elevated salt level. None of these levels would create a problem during <br />reclamation if proper cultural treatments are used. However, it was not <br />evident whether one distinct layer was elevating these levels or whether the <br />chemical characteristics were uniform throughout the four foot sampling depth. <br />