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-37- Probable Hydrologic Consequences - Ground Water (Cont'd) Fractured roof conditions have produced mine inflows at the Blue Ribbon Mine. To date, these inflows have been few, have been of short duration and have involved relatively minor amounts of water. The characteristics of these inflows indicate that the source of water has a limited recharge area and has a limited storage capacity (i.e., limited thicY,ness and areal extent). The water flowing from these fractures most likely originates from overlying perched aquifers in lenticular sandstones and from the fractures themselves. The pulling of coal pillars within the mines may produce subsidence. The subsidence may impact the overlying water-bearing strata with the faesaverde Formation. However, no overlying strata are used for water supplies and no significant spring flows to date have been observed eminating from these strata. The potential future use of the lenticular sandstones for water supplies is limited by: 1) the steepness of the stream valley slopes, 2) the depth of drilling, 3) the low well yields which are expected from the tight, fine-grained sandstones, and 4) the Limited recharge areas of lenticular sandstones. The Blue Ribbon Mine will not affect the quality of water in the overlying strata. The "E" coal seam is not an aquifer. The mine workings are dry, except in a few areas of fracturing. Surface Water The following discussion is oriented toward those impacts which may affect Hubbard Creek. Effects upon the North Fork of the Gunnison River will be similar, but of a much smaller magnitude. Hubbard Creek runs through the permit area between the mine bench and the coal stockpile and is the only tributary of the North Fork of the Gunnison which may be affected by operations at the Blue Ribbon Mine. Blue Ribbon Coal Company operates an adjudicated well completed in the alluvium of Hubbard Creek adjacent to the mine bench. Water from this well is used for sanitary and industrial purposes. Water is produced at an average rate of about 8 gallons per minute. Blue Ribbon Coal Company has obtained conditional rights for the use of this water and ditch and storage rights for Pond 1 which serves as a source of augmentation water to charge the well. For a discussion of these rights, please see Section VII, "Water Rights and Replacement", in this document and pg. 39, Section 2.04 of the Blue Ribbon Mine permit application. Removal of 8 gpm is a negligible reduction in the average flow of Hubbard Creek. For example, in 1980, removal of 8 gpm equalled only 0.60 of the low flow of 3 cfs. Both the operation of the water supply well and the operation of the augmentation reservoir are not anticipated to have any discernable effects upon the hydrologic balance of Hubbard Creek or the use of Hubbard Creek water down- stream. The anticipated impacts of the Blue Ribbon Mine onthe quality of water flowing in Hubbard Creek are minimal. Surface flows from disturbed areas are routed through sediment ponds designed to discharge water meeting the effluent limi- tations of Rule 4.05.2(7).