Laserfiche WebLink
I • 4.05 HYDROLOGIC BALANCE <br />4.05.1 General Requirements <br />The surface mining activities at Colowyo have been planned and will be conducted to <br />minimize changes in the prevailing hydrologic balance, in both the permit and adjacent areas, <br />and to prevent long term adverse changes in the balance that might result from the activities <br />As a preliminary step in minimizing adverse changes, hydrologic baseline information has <br />been and is being collected, compiled and analyzed. The baseline monitoring programs are <br />outlined in Section 2.04.7. This data provides detailed information on quality and quantity of <br />surface water, drainage patterns, and geology. The description of the current hydrologic <br />monitoring program is included in the following pages and results of the current monitoring <br />program are included in the Annual Reports for 1983 to present. In addition, Section 2.05.6 <br />details the specific mining and reclamation techniques which Colowyo will implement to <br />minimize changes to the hydrologic balance. <br />The post-mining land use as described in detail under Section 2.05.5, will be rangeland. <br />Changes in the hydrologic balance will be minimized so that the post-mining land use will <br />not be adversely affected. <br />Water quality standards and effluent limitations at the existing mining operation are regulated <br />by the U. S. Environmental Protection Agency and the Colorado Department of Health. under <br />• the terms of an NPDES Permit, (See Exhibit 7, Hydrological Information), and by the Coal <br />Regulations of the Colorado Mined Land Reclamation Board. The applicable effluent <br />limitations will be met by using treatment methods which will include prompt revegetation, <br />minimizing disturbed areas, sediment retention, use of contour furrows, terraces, sediment <br />ponds and, if necessary, strategically placed energy dissipaters, such as riprap, check dams, <br />mulches, filters and dugouts. Water quality control measures are discussed in detail under <br />Section 2.05.4 and 2.05.6. <br />Where practicable, diversion methods will be used to change the flow of water from <br />undisturbed areas so as to bypass the disturbed areas rather than using treatment facilities. <br />The principal technique to be used for this purpose will be diversion ditches. These diversion <br />ditches are located on the Hydrology -South Map (Map 12) and the Hydrology -North Map <br />(Map 11), and discussed in detail under Section 2.05.6. Their design is specified in Exhibit 7, <br />Hydrological Information. <br />No acid-forming materials are present in the area to be mined which would require selective <br />placement and sealing of overburden. The chemical characteristics of the overburden is <br />presented under Section 2.04.6. The overburden sampling program is presented under Section <br />2.05. Results of the current overburden <br />4.05-1 Revision Date: 6/28/05 <br />Revision No.: MR-73 <br />