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Daniel t. Hernandez, Colorado Division of Minerals and Geology Response [o Comments on Draft Permit, Colowyo Coal Company, L. P. CDPS No. CO-0045161 (pending). Moffat County Page 3. However, we will offer Colowyo or any other permittee the opportunity to demonstrate that an allowance should be made for a particular discharge if the effective "window" was significantly shortened, for example, because rainfall occurred a long distance from the pond and travel time to the pond was long enough that no or little discharge occurred before the 48-hour clock elapsed. We would not consider it appropriate to consider exempting a discharge because it took a few hours for the flow to reach [he pond but would consider a situation where flow did not reach the pond for 24+ hours. We have no set procedure at this time for this, the petnrittee would have to provide a convincing argument as to why a particular discharge should be treated differently from others. 6 This question addresses manual dewatering. Colowyo is converting all ponds to automatic dewatering so the question is no longer relevant other than that the Division concurs with you that all manual discharge; must meet primary limitations. Kimberley Wolf with Colowyo has recently acknowledged awareness of this. This question addresses water pumped from pits. Colowyo has consented to permit conditions that would establish internal discharge points and require [hem [o monitor this water prior to discharge to a pond to demonstrate [hat it will meet TSS and total recoverable iron limitations. This has not been implemented in the permit before this, but as intended, if [he permittee demonstrates that pit water (or vehicle wash water) meets primary limitations prior to discharge to the pond the combined discharge oul be eligible for alternate limitations. At this point, [his appears acceptable to the Division. This comment pertains to manual discharges, which will have effectively ceased in the near future. The Division expects that, in the future, manual discharges will occur very infrequently and only to facilitate dredging of sediment or pond repairs. Such discharges would likely fall at a time when no precipitation induced discharges were occurring, thus monitoring would be required. [f CDMG is on site at the time manual dewatering is occurring, you can collect samples. 9. We find no reason to not include your suggested permit language. As you suggest, this is intended to relate only [o pond discharges. We believe that it reinforces requirements already in the permit. 10. This comment relates to the section of the permit that mentions post-mining areas. This section is advisory to the permittee to make them aware that other limitations and conditions apply to post-mining areas. The WQCD routinely consults with your Division to verify that a facility or applicable portion of a facility qualifies as a post-mining area. Additionally, we routinely copy your Division on all draft and final permits and amendments. If you are aware a[ any time that you are not receiving copies at the appropriate time, please let us know. We consider your input extremely valuable. 11. In both the first and second scenarios, as in 5. above, the discharge would be eligible for exemption from primary limitations through 48 hours after the event ended and the exemptible parameters would be TSS and total iron. After 48 hours, all discharges would have to meet [he primary limitations. It is important to note that the term "eligible" is used. The exemption is not automatic, a permittee needs to provide proof [hat primary limitations could not be met. The Division considers factors such as was the pond properly operated and maintained prior to and during [he discharge, in addition to the occurrence and size of a storm event, in determining eligibility for the exemption.