2013-02-04_REVISION - C1981008 (3)

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JoEllen Turner 970 - 864 -7682 p.15 Botch Environmental Pollution Consultfng,LLC October 2, 2012 of the Colorado Mined Land Reclamation Board, § 4.25.1(1). Similarly, the regulations require that WF replace the A horizon to a depth that equals or exceeds the thickness of the original soil (--6 inches based on the official description of the Darvey and Barx series), Section 4.25.4(5). There is plenty of evidence showing that the depth of a soil can impact crop yield. It was concluded in a recent study the " Shallow soils presented lower [corn] yield than deep soils at a given rainfall." sec Calvino, P. A.; Andrade, F. H.; Sadras, V. 0., Maize yield as affected by water availability, soil depth, and crop management. Agronomy Journal 2003, 95, 275 -281. Since up to 200,000 cubic yard of topsoil ( -12 inches) was removed from the Morgan property this soil or soil of similar high quality must be returned to the property. In addition, the reclaimed soil can not have any bench 1 soil substitute within the top 40 inches since that would not meet the soil criteria established for Land Capability Classification IIe, which Barx soil falls into. Barx and Darvey soils are —60 inches deep (National Cooperative Soil Survey, U.S.A. LOCATION BARX UT +AZ CO, Established Series, Rev. DTH/KS /CSW /JWB 04/2011 - BARX SERIES). Jim Boyd and Dave Dearstyne (MRCS) recommended the following soil depth replacement approach (Jim Boyd letter of Nov. 16, 2010); At least 21 inches of mixed topsoil, or lift A topsoil, of Barx origin be placed over at least 19 inches of Barx subsoil (lift B) or similar material, to create a Land Capability Classification He soil with minimum soil depth of 40 inches. This minimum 40 inches of Barx or similar je.g., Darvey] is to overlay 14 inches of Bench 1 Subsoil Substitute, or whatever thickness is needed, to provide a total minimum combined soil thickness of 54 inches. Reclaimed slopes are not to exceed 3 %, and rock picking will be required after placement and ripping of any Bench 1 Subsoil Substitute material and before placement of Barx subsoil or topsoil. Since the current reclamation plan indicates that the Bench I Subsoil Substitute will be present from a depth of 21 to 54 inches on large areas (at least 20 acres) within the Morgan property that indicates to me that this area will not meet the requirements for a Land Capability Classification IIe soil. Mr. Dejoia states that approximately 56 acres on the Morgan property (which totals approximately 110 acres) consisted of PF soils before mining of the property was initiated. As noted above, both the Barx and Darvey qualify as prime farmland soils, though only the Baran appears to have been mapped as such pre - mining. I disagree with the conclusion that only 56 acres of the Morgan property was prime farmland soils because the other soils present on the Morgan property (such as Darvey) meet the classification for prime farmland. The Darvey is functionally very similar to the Barx, which Mr. Dejoia admits to be prime. I have the following additional concerns regarding Mr. Dejoia's analysis: 7.1 Soil pH: Return pH to the pH of the native soil. Alfalfa yield is highest at pH 6.8. A pH of 7.5 is borderline to when the pH may negatively influence the crop yield. Based on the calculated confidence interval for the substitute soil the pH could easily be 7.8. The pH of the Barx Lift B is numerically lower and likely also statistically lower if an ANOVA test was conducted on a data 14 p Page PLTF 002488