2022-11-07_GENERAL DOCUMENTS - C1981041

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Possible hydrologic impacts on quantities of surface water due to the Roadside and Cameo Mines include impacts to: 1. Quantity of flow in the Colorado River, 2. Quantities of flow in Rapid and Cottonwood Creeks, 3. Surface seeps and springs above the Roadside Mine, 4. Dams and reservoirs above the Roadside Mine, and 5. Impacts due to water consumption by mine operations. 1. The permittee states that approximately 0.47 cfs of mine discharge water is added to the Colorado River, increasing the flow by an average of 0.01 percent. Most of the water pumped from the Roadside North Portal ultimately comes from the Colorado River by way of aquifers which subcrop below the alluvium of the river. In addition, the water pumped from the Roadside Mine would naturally contribute to base flows in the Colorado River through aquifer discharges to the river. Therefore,the mining operation should have an insignificant effect on the quantity of water in the surface and groundwater systems of the Colorado River. 2. Monitoring of both Cottonwood and Rapid Creek since 1985 has shown minimal disturbance due to subsidence. Both creeks have infrequent flow patterns. Cottonwood Creek, although a major tributary to Rapid Creek, is dry by late summer. Rapid Creek is intermittent in nature. Where surface cracking was observed, within a year the crack was refilled with sediment from the creek channel. Minor ponding has also been observed to have taken place in the subsided areas. This ponding was for a relatively short period and has disappeared. Monitoring indicates that little surface flow has been lost due to subsidence in the Rapid Creek Basin. 3. Twenty-five springs have been located in the Rapid Creek Basin. All of these springs are outside the subsidence angle of draw. None of the springs overlie present or planned underground mine workings. Mining will not affect the natural springs. 4. There are seven reservoirs in the Rapid Creek Basin, all outside the boundaries of the permit area. The Bureau of Land Management has stated, and the Division agrees,that six will not be affected by coal mining in the area. Cabin Reservoir, which is located outside of the permit area, adjacent to the southeast corner of the South Portals mine plan area, could possibly be impacted by subsidence if future mining were to occur within the immediately adjacent portions of the permit area. However, coal extraction operations were suspended in the South Portals mine area in January, 1997, and operations did not resume. Subsequently,the operator filed notice of permanent cessation of operations,and the South Portals were sealed. Mine workings are separated by over a mile from the reservoir, and no further mining is currently proposed. Consequently, there will be no impact to Cabin Reservoir. 32