1999-12-15_GENERAL DOCUMENTS - M1999051

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DIVISION OF MINERALS AND GEOLOGY Department of Natural Resources 1313 Sherman St., Room 215 Denver, Colorado 80203 Phone: (303) 866 -3567 FAX: (303) 832 -8106 June 18, 1999 Mr. Roger Day AmerAlia, Inc. P.O. Box 1330 Rifle, CO 81650 Dear Mr. Day: • STATE OF COLORADO RE: Adequacy of the Application, Rock School Lease Experimental Nahcolite Mine Project, File No. M -99 -051 The following issues remain to be addressed for the Rock School Lease Project reclamation permit application to meet the minimum requirements of the Colorado Mined Land Reclamation Act for permit issuance. Please respond to each of the listed items prior to the established decision date of July 27, 1999 or provide a written request for extension of the decision date. To avoid having the DMG extend the decision date, provide your responses by July 6, 1999. D I V I S I O N O F MINERALS GEOLOGY RECLAMATION MINING•SAFETY Bill Owens Governor Greg E. Walther Executive Director Michael B. Long Division Director 1. The Division of Minerals and Geology (DMG) has determined that the Rock School Lease Project is a Designated Mining Operation (DMO) as defined in Rule 1.1(14) of the Hard Rock/Metal Mining Rules and Regulations of the Mined Land Reclamation Board (Rules). The basis for this determination is found in Rule 1.1(14)(b), which states mining operations will be designated if "toxic or acid - forming materials will be exposed or disturbed as a result of mining operations." The proposed mine plan may expose or disturb toxic materials in the following two ways. a) Drill holes used to inject processing solution and extract dissolved nahcolite from the target mining zone will be drilled through the lower aquifer. Some zones within the lower aquifer are known to exhibit concentrations of certain toxic constituents that exceed human health and/or agricultural standards for ground water. The potential for comingling of poorer quality lower aquifer water with the ground water of the upper aquifer if leakage were to occur along the cased and cemented production wells would make the wells Environmental Protection Facilities as defined in Rule 1.1(15). b) The heated and pressurized solutions injected into the saline zone for recovery of nahcolite are intended to dissolve only sodium bicarbonate. During this process the heated solution may dissolve other minerals containing toxic elements such as fluoride and possibly barium. Other elements of concern that have been dissolved by ground water in contact with the rocks of the Parachute Creek member of the Green River formation include boron and lithium. It reasonable to assume that toxic constituents documented to be dissolved in ground water in the lower