1997-06-13_REVISION - M1981302 (60)

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Page 20 operator and adequate to meet the performance standards of the statue and regulations. Based on this analysis, the Boulder County Commissioner's allegations that the pending permit amendment is a substantial and detrimental change from the original reclamation plan is not a basis for denial of the amendment application. ISSUE 6 Whether topsoil replacement as proposed in the Amendment is sufficient to support the plant species to be established in reclamation. Comment: "Insufficient topsoil is present on much of the reclaimed land and is required to attain the end use. I have documented and discussed the insufficiency in my letters of 4/20/97 and 7/15/96. The DMG expectation that 6-8 inches of topsoil depth is being replaced is confirmed in its correspondences; e.g. the 11/14/89 inspection report of Daniel Hernandez and the 4/30/97 letter from Mr. Gregg Squire to Mr. Michael Hart. Both the vegetation description in the 1981 permit application and the Soil Conservation Service data for the soil map units indicate that much of the site contained ample topsoil or overburden or[sic] to begin with (contradicting Mr. Michael Hart's 5/14/97 letter). "Therefore I request that CMLRB uphold its own requirement that revegetated areas be topsoiled to the committed 6-8 inches minimum depth." Response: The vegetation description in the 1981 permit application and the Soil Conservation Service data for the soil map units are based on general descriptions for the soil types found on the permit area. These descriptions are based on the average pedon for these types of soil. However, topsoil salvage requirements on mine sites must be based on what exists at the mine site at the time of permit issuance. Aerial photo maps submitted with the permit application and stamped received by the Division on December 24, 1981 indicate that pre-law mining had disturbed at least 26 acres of ground. This was divided into an approximately 14-acre lake and a 12-acre mining area(part of Stage 1)that was assumed to have no topsoil left for salvage. These maps also indicated that very little topsoil existed in the northern 20 acres(Stage U) and the remaining approximately 40 acres of Stage III(the rest of the 53.5 acres of Stage III is taken up by portions of the pre-law lake). The rest of the site was determined by the Soil Conservation Service to contain mostly Niwot Series soils. These soils have approximately 6 inches of All horizon material that would be salvageable for reclamation purposes. Below that horizon, an At horizon exists to 14 inches which would also be salvagable for reclamation purposes. If one assumes that the operator salvaged as much topsoil from this remaining area of the disturbed lands as possible, that would amount to approximately 74 acres that topsoil could be salvaged from to an approximately 14-inch depth. If 14 inches of topsoil could be salvaged from these 74 acres, then one would get approximately