2019-05-29_REVISION - C1981018 (11)

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26 utility lines which pass over, under, or through the permit area. Utility lines pass through the permit area but are not affected by the support facilities. Therefore the Division previously approved those activities (4.04(6)). III. Hydrologic Balance - Rule 4.05 Volume 1, Section II.C of the Deserado Mine permit application includes an assessment of the probably hydrologic consequences of the proposed mining operation. Each year, Deserado assesses the ongoing impacts to the hydrologic system in its annual hydrologic report. The probable hydrologic consequences as set forth in Volume 1, Section II.C are summarized below. The small area exemption sites are listed in Section IV.J.5 of the permit application. Sedimentation demonstrations for small area exemptions are provided in Illustration 44, of Volume 12, and the locations are shown on Map 147. A. Water Quality Standards and Effluent Limitations With the exception of approved small area exemptions, all discharges from the Deserado Mine will pass through sediment ponds or treatment facilities designed to ensure that all discharges meet applicable effluent limits under the operator’s Colorado Discharge Permit System (CDPS) permit. Any water pumped from underground workings will be clarified by allowing sufficient settling time in underground sumps, abandoned areas, or treatment ponds prior to discharge to the surface. Approved mine water discharge sites have been inactive since the northern portion of the “D” seam mining district was sealed off in 1996. In January, 1997, the operator was granted approval to discharge preparation plant thickener water within sealed sections of the “D” seam mine workings, pursuant to the requirements of Rule 2.05.3(9). A storm water permit and spill prevention containment and control plan associated with the CDPS permit also dictate preventive and mitigation measures for ensuring that all water leaving the mine site meets applicable effluent limits. Due to facility site layout and sediment pond location, existing sediment ponds which provide sediment control for the D/B portal facilities will necessarily be eliminated in conjunction with reclamation grading of the facility areas. Alternative sediment treatment facilities to ensure discharge effluent limit compliance for this location following reclamation grading will be necessary. Similarly, existing small area exemption sediment controls for the East Portal Ventilation facility area will be eliminated during reclamation grading, and alternative measures will be necessary. A specific plan for controlling sedimentation during and after reclamation grading has been provided for the D/B portal area, and a generalized post-grading sediment control plan has been provided for the East Portal Area. A description is provided within Section V.B.6 of the application to provide a more detailed post-grading sediment control plan and demonstration for the East Portal.