2009-06-22_GENERAL DOCUMENTS - C1981033 (2)

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North Fork of the Gunnison River. Several small bodies of alluvium lie along the course of the North Fork of the Gunnison River. The reclaimed area of the Bear No. 3 Mine facilities overlies alluvial material. This area does not meet the ten-acre minimum size criterion; therefore, the area is not an alluvial valley floor. The Mountain Coal Company study identified a much larger body of alluvium downstream from Somerset, Colorado. Areas currently supporting agriculture have been identified within Sections 13 and 14, T135, R91 W, associated with the North Fork of the Gunnison River. Alluvium in Section 18, T13S, R90W (1.3 miles downstream of Bear No. 3) and Sections 13 and 14, T13S, R91W (2.5 to 4 miles downstream) meet the criteria of alluvial valley floors. The alluvial valley floor probably continues downstream; however, no determination has been made for the North Fork valley between Section 14, T13S, R91W and Section 29, T13S, R91W, (2.5 to 6.5 miles downstream) because it will not be impacted. The Division is required to make specific written findings regarding the effect of mining upon any AVFs within the permit and adjacent area pursuant to Rule 2.06.8. The AVF is not within the mine permit area, and will not be physically disturbed by the mining activities. No impacts to the AVF are anticipated. The Division finds that the surface coal mining operations would not interrupt, discontinue, or preclude farming on the alluvial valley floor pursuant to Rule 2.06.8(5)(a)(I)(A)(I). Surface disturbances associated with the Bear No. 3 Mine are located more than a mile upstream of the alluvial valley floor and would not affect agricultural activities on the alluvial valley floor. The alluvial valley floor would not be undermined by the proposed operations. 2. Pursuant to Rule 2.06.8(5)(a)(I)(A)(II), the Division finds that the proposed surface coal mining operations would not materially damage the quantity and quality of water in surface and groundwater systems that supply this water to alluvial valley floor. 3. The Division finds that surface coal mining and reclamation operations will be conducted to preserve, throughout the mining reclamation process, the essential hydrologic functions of the alluvial valley floor pursuant to Rule 2.06.8(5)(a)(iii). No change in the quantity of water available to alluvial deposits adjacent to the North Fork of the Gunnison River is expected to result from mining activities by Bear Coal Company. No diminution in surface water runoff from the permit area is expected to occur; therefore, no decrease in the flow of the North Fork of the Gunnison is expected. The undisturbed land overlying the Bear mine workings should not be significantly impacted by mining; therefore, no impacts to the surface water system are anticipated. Surface runoff from the eight acre disturbed area of the Bear No. 3 Mine was expected to increase during active mining due to the low infiltration capacity of the roads and parking areas at the mine. The increase in surface runoff from this small area is insignificant when compared to the much larger flow in the North Fork of the Gunnison River. No significant changes to water quality are expected to occur as a result of mining at the Bear No. 3 Mine. The water quality of surface runoff from the undisturbed permit area will not be affected by mining. No subsidence problems are anticipated which could increase landslide frequency in the permit area, and increase the amounts of dissolved and suspended solids in adjacent streams. Water quality of surface runoff from the disturbed area is controlled by NPDES discharge limitations. Infrequent discharges from the Bear 26