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.. <br />~, <br />Mr. Steven Self <br />Page 8 <br />February 7, 1980 <br />L. Acid/Toxic Ffaterials (IV 62-63 and IV -65) <br />The staff disagrees with the statement in these sections. Existence <br />or lack of acid and toxic materials cannot be "inferred" based just <br />on the parameters defined in these sections. Data in Appendix IZI-2 <br />indicates elevated TDS levels for the mine discharge waters. By <br />definition, toxic mine drainage means"water discharged which <br />contains a substance that through chemical action or physical effects, <br />is Likely to kill, injure or impair biota commonly present in the <br />area. ." Without knowing the type of salts in the discharge, the <br />effects cannot be properly evaluated. Therefore, an analysis of <br />the types and amounts of salts in mine water discharge for all the <br />mines is needed. The underground water discharge ponds only treat <br />for high suspended solids, not high TDS. In fact, addition of <br />floculants would likely increase the salt load. The need for roof <br />and floor analysis for the "F" seam has previously been addressed. <br />M. Nydrologic Balance, Groundwater Monitoring, Water Rights, Augmentation <br />Plan. <br />These sections are being reviewed by the State Engineer's Office. <br />Their comments will be forwarded when available. <br />N. Sediment Control System <br />1. General Corrunents ' <br />The applicant should be advised that the Division has only <br />approved the drainage and sediment control system in the Eagle NS <br />and silo area and the Eagle b9 area (with conditions). Notation on <br />sediment pond drawings that other areas have been approved are <br />incorrect. <br />2. Area SA <br />a. Why is the discharge point on pond 5A-P1 indicated as the <br />emergency rather than principal spillway? <br />b. Why is a 25-year-peak of 15 cfs shown on the pond calculation <br />sheet while 6.19 crs was used in sizing the emergency spillway <br />(blueprint)? <br />c. The SA area has two underground water discharge ponds (as <br />observed in the field) rather than the one shown on Ffap yV-9. Map <br />ZV-9 should be adjusted accordingly. Zn addition, the design of <br />these underground discharge ponds should be detailed to provide <br />adequate demonstration that the discharge from these ponds will meet <br />the effluent limitation per the requirements of 817.50 and 817.92(a). <br />This will include specifying the amount and rate of water discharged <br />from the mine. <br />3. Area SH <br />.u <br />a. Ditch SII-02 is ca1;;ulated to drain 5.5 acres, but it drains <br />