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III. Hydrologic Balance - Rule 4.05 <br />A. Water Quality Standards and Effluent Limitations <br />All discharges from the Seneca II site from storm runoff and spoil springs will <br />pass though a sediment pond designed to ensure that all discharges meet effluent <br />limits in Seneca Coal Company's NPDES permit for the Seneca II Mine. A storm <br />water permit and spill prevention containment and control plan associated with the <br />NPDES permit also dictate preventative and mitigation measures for ensuring that <br />all water leaving the mine site meets applicable effluent limits. <br />There are no variances from the requirements of the Rules and Regulations <br />proposed at this time. Therefore, no specific findings regarding water quality <br />standards have been made (4.05.2(3)(b)(I)). <br />B. Diversions and Conveyance of Overland Flow <br />Drainage channels have been reestablished to their approximate original natural <br />pattern to minimize erosion, to conserve soil moisture and promote vegetation. <br />Drainage reestablishment in the reduced permit area consisted of the certified <br />design and construction of one permanent postmining drainage channel (SIIPM-8). <br />This channel is shown on Drawing 2.05-Ml. Information regarding the design of <br />the channel is provided in Tab 7 and Tab 13 of the permit application. <br />C. Sedimentation Ponds <br />Seneca Coal Company will primarily use a sediment pond to prevent additional <br />contributions of sediment to streamflow or runoff outside the permit area due to <br />mining disturbances. The existing sediment pond in the remaining permit area is <br />Pond 008. Information regarding the design of the pond is provided in Tab 7 of <br />the permit application. <br />Pond 008 was constructed in the Fish Creek drainage basin in a tributary referred <br />to as Bond Creek. NPDES discharge site 008 replaced 007, which was mined <br />through. Pond 008 drains an area of 247 acres of which 226 acres is disturbed. <br />The pond is designed to provide storage for a 10-year, 24-hour precipitation event <br />with 2.1 acre-feet of runoff and has a capacity of 16.4 acre-feet. Pond 008 is <br />permitted as a permanent impoundment. <br />D. Acid-forming and Toxic-forming Spoil <br />The applicant has submitted analysis of the geochemical characteristics of the <br />overburden and interburden found in the Seneca II Mine permit area. The sample <br />parameters can be found in Volume 3, Tab 6. Acid and toxic-forming materials <br />were not predicted to constitute a problem in the Wadge mining area. <br />12