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(Page 2) MINE ID # OR PROSPECTING ID #: M-iaRR-naa INSPECTION DATE: 7aniiarv 17, vnn~ INSPECTORS INITIALS: ni a An inspection of the Coal Creek Resources Mine (M-1988-044) operated by Centennial Materials, Inc. was conducted at the request of the State of Colorado Board of Land Commissioners. The operator and his consultant had been notified several days in advance of the inspection and accompanied this inspector. The principle aim of the inspection, as requested by the Board of Land Commissioners was to evaluate the bond to see if it is adequate. The permit area ~ronsists of 1,590 acres, of which approximately 58 acres are planned to be disturbed at any time. The bond amount of $193,100 is based upon the disturbance of 58 acres. The Coal Creek Resources Mine includes two separate operations, the lowland operation is mining the stream channel on the south end of the property, and the other, the upland, is mining a sand deposit located on the tops of nearby rolling hills. Access to the mining operations is by driving east of E-470 on Quincy Avenue approximately 4 miles. The mine shares an access with a batch plant operated by Owens Concrete. The mine permit sign is small but prominently located and legible, and the mining operation appears to be within the permit boundaries. The lowland operation is currently mining approximately 5 feet deep compared with an allowable depth of mining of 8 feet, this mining depth is currently limited by a clay layer. The reduced mining depth (8 feet or less) apparently agrees with the cottonwood trees as it minimizes the impact on groundwater. The operation has experienced no cottonwood die-off since reducing the mining depth to 8 feet or less. Mining in the lowland is expected to be completed in the next two or three years. This operation affects approximately 5 acres per year. Currently approximately 48 acres have been affected in the lowland operation, with approximately 30 acres under reclamation (Annual Report). The lowland reclamation accomplished to date appears to be quite successful. It is well graded and appears to have a diverse representation of grass species. Two 5 acre areas have been planted with cottonwood trees and fenced to exclude grazing. These fenced areas protect cottonwood plantings and other riparian species from the cattle, and the cottonwoods are thriving. The trees currently appear to range from 8 to 20 feet tall and are part of a complete riparian habitat. The fuel storage tank in the lowland area is protected by a small berm constructed of the sand that is being mined. This facility should be surrounded with a berm, capable of containing 133 % of the capacity of the tank and is impermeable to the degree of 1x10-'' cm/sec. The simplest way to accomplish this is to place the tank in a pond lined with impermeable geosynthetic membrane. This same approach should be taken with all fuel storage located within the permit area. This will be noted as a problem on page 4. The upland area consists of a pit mined with near vertical walls approximately 20 feet high. The sand appears to stand without much sloughing and this appears to be standard practice. This inspector is not commenting on the safety of the practice, but the operator is cautioned to remind employees to stay away from the highwall for their protection. Roads throughout the operation appear well graded and well maintained. The processing facility was experiencing frozen pipes at the time of the inspection, therefore was not operating, but appeared to comply with the permit requirements. Approximately 124 acres have been affected in the upland area, with approximately 48 acres being reclamaimed by the operator and 23 acres (Overlap) being reclamation by others (Annual Report). The reclaimed upland areas appear well sloped and well vegetated with a diverse community of grass species. According to the annual reports, approximately 172 acres of land has been affected to date, with none released. Concurrent reclamation is being conducted and appears extremely well reclaimed, however, it appears that the acreage affected exceeds the acreage allo~.ved in the permit of 58 acres. This is considered to be a problem, and is addressed on page 4.