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to the alluvial ground water would also have had the potential to impact the <br />quality or quantity of water within the Colorado River. <br />The subcrop of the Wheeler seam is located approximately 55 feet above the <br />alluvium and dips steeply away from the alluvial body. Undermining of the <br />alluvial body did not occur during the life of the mine. Therefore, dewatering <br />of the Wheeler seam due to mining is not an expected impact to the alluvium <br />or surface water system of the Colorado River. (For further information see <br />Alluvial Valley Floor, Section IX of this document.) <br />Actual operations for the Coal Ridge No. 1 Mine included only minor <br />disturbance on the surface, and developmental work for two portals. The <br />surface disturbance totalled approximately 35 acres. NCIG has constructed <br />drainage control structures which treat runoff from 50 acres, only 35 of which <br />were disturbed. Runoff from the majority of the area (37 acres) is treated prior <br />to release in Sediment Pond A. There are 13 acres which include undisturbed <br />area and small disturbed areas which have been designated as alternate <br />sediment control areas, where runoff is detained in catchment sumps and filtered <br />prior to discharge. <br />The major water rights owned by the applicant are from the Vulcan Ditch, <br />which originates in Canyon Creek, a tributary to the Colorado River on the <br />north side of the river. The water from this ditch is siphoned underneath the <br />Colorado River and has historically been used to flood irrigate the alluvial valley <br />floor north and east of the surface facilities. Since plans to operate the mine <br />have been abandoned, there will be no consumptive use of water other than <br />irrigation. During low-flow periods, the applicant has committed to giving <br />priority to irrigation of the historic alluvial valley floor (see Stipulation No. 4). <br />Accordingly, the operation is not expected to impact flows in the Colorado <br />River, or to have a negative impact on surface water rights holders. <br />In conclusion, no significant impacts to the hydrologic balance are projected at <br />the Coal Ridge No. 1 facilities. Monitoring data from 1988 to 1994 indicate no <br />adverse impacts which could be attributed to the operation have occurred. <br />An analysis of Probable Hydrologic Consequences of the Coal Ridge No. 1 Mine <br />has been performed by the applicant, as required under Rule 2.05.6(3). Several <br />effects from the proposed operations which were identified never occurred. <br />Therefore there have not been and are not predicted to be effects which would <br />adversely impact the overall hydrologic balance of the permit and adjacent <br />areas. The operations proposed within the permit area were designed to <br />prevent material damage to the hydrologic balance outside the proposed permit <br />area. Appropriate measures within the application were implemented to ensure <br />the protection of the quality and quantity of surface and ground waters within <br />both the proposed permit and adjacent areas, from the adverse effects of the <br />proposed mining activities. <br />Coal Ridge No. 1 Mine ~ 14 Permit Renewal No. 3 <br />