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"All of Colowyo' s ponds aze currently operated as containment ponds. Such ponds shall be considered to have only manual dewatering capability and relief under the alternate limitations provision shall be available to the extent required to regain the necessary IO-year, 24-hour capacity in such ponds. For any ponds that Colowyo may operate in the future as treatment ponds, consistent with the CDMG design criteria, any manual dewatering of such treatment ponds must meet primary dischazge limitations." Please refer to the GENERAL COMMENTS section of the letter for a discussion of the present and future operation of Colowyo's sediment control ponds. The CDMG has copies of all of Colowyo's hydrological modeling and the CDMG is encouraged to review each modeling effort. Colowyo would be pleased to review pond hydrology/sedimentology models with the CDMG. 7. Colowyo is not contending here that water pumped from coal production pits should be entitled to the Alternate Limitations. It is important to note, however, that this is because of the control the operator has over the pumping, not the quality of the water. As Colowyo demonstrated in its March 6, 1996 letter to WQCD (letter from Colowyo's counsel D. Kennedy to WQCD), surface runoff that comes into contact with the pit (the source of Colowyo's pit pumped water) remains surface runoff for purposes of discharge permitting, and is entitled to be permitted under the general discharge permit for coal mining operations. Surface runoff pumped from the pit poses no additional water quality concerns than other surface runoff at mining operations. The issue in the draft permit CO-0045161 is how to ensure that gravity drained surface runoff is entitled to the Alternate Limitations, even when it has been combined with pit pumped water in a sediment pond. WQCD's draft permit would allow dischazges from sediment control ponds to be subject to the Alternate Limitations when it can be shown that the majority of the discharge is from gravity drained surface runoff. In Colowyo's comments, dated September 30, 1997, on the draft permit, Colowyo proposed that the major source language be deleted and, instead, that one way for Colowyo to demonstrate that surface runoff caused the exceedance of the Primary Limitations (and not the pit pumped water), prior to dischazge into the sediment pond is to sample the pit pumped water to ensure it meets the Primary Effluent Limitations. Colowyo believes this addresses any concern either WQCD or CDMG might have with the dischazge of pit pumped water and its entitlement to use the Alternate Limitations for otherwise qualifying dischares that have been combined with pit pumped water.