Laserfiche WebLink
COLORADO DEPARTMENT OF PUBLIC HEALTHAND ENVIRONMENT, Water Quality Control Division <br />Rationale, Page 5, COG-0850000 Coal Mining General Permit <br />Table III-3a: Effluent Limitations and Monitoring Requirements -Post Mining reclamation Areas <br />`~ Limitations <br />Parameter 30-Day 7-Day Daily Rationale Monitoring Sample <br />Avg. Avg. Max. Frequency Type <br />~___~_________________________General Permit Requirements--____________~_________________________ <br />Flow, MGD Report NA Report Discharge Evaluation Continuous / z Recorder / <br /> Instantaneous In-situ <br />pH, s.u. N/A NA 6.5-9.0 Water Quality Standards Weekly Grab <br />Total Suspended Solids, mg/Z 30 45 NA State Effluent Regulations Weekly Grab <br />Oil and Grease, mg/1 N/A NA 10 State Effluent Regulations Weekly Visual 3 <br />____________~____M_~______ _Federal Effluent Limitation Guidelines------------------___~_____~________ <br />Settleable Solids, ml/l Report NA 0.5 Federal ELG Weekly Grab <br />_~_______________~__~____________~__Site Specific L imitations--____~_~_~____________~___w______ <br />Total Dissolved Solids, rng/Z * Report NA Report Salinity Regulations Quarterly a Grab <br />Total Phosphorus (as P), mg/Z ** Report NA Various Control Regulations Monthly Grab <br />Total Recoverable Iron, ug/Z *** 1000 NA NA Water Quality Standards Weekly Grab <br />Other Pollutants of Concern Various NA Various Water Quality Standards Weekly Grab <br />Whole Effluent Toxicity (WET) <br />Chronic Stat Diff and IC25 > IWC State Permit Limitations Quarterly 3 Grab/Test <br />Acute LC50 > 100% State Permit Limitations Grab <br />Footnotes 1-4, *, **, and *** - See Footnotes under Table III-1 and Table III-2 <br />Alternate Limitations For Post-Mining Reclamation Areas -Table III-3b contains limitations for any discharge or <br />increase in the volume of a discharge from a reclamation area, caused by precipitation within any 24-hour period <br />greater than the 10-vear, 24-hour precipitation event (or snowmelt of equivalent volume) may substitute the following <br />limitations for these specific parameters only, subject to burden of proof requirements described in Part I.B.4 of the <br />permit. ' <br />Table III-3b: Alternate Effluent Limitations and Monitoring Requirements -Post Mining reclamation Areas <br />Limitations Monitoring Sample <br />Parameter 30-Day 7-Day Daily Rationale Frequency 1 Type <br />Avg. Avg. Max. <br />__~_w_~_____~__________~Federal Effluent Limitation Guidelines----------------------------------------- <br />Settleable Solids, ml/Z Report NA Report Federal ELG Weekl Grab <br />b. Post Mining Underground Areas -Table III-4 applies to this category, subject to 40 CFR Part 434 Subpart E (Post <br />Mining Areas). The following limitations apply to underground areas. The federal ELG limitations would apply until <br />bond release. If these wastewaters are combined with other waters under Part I.B.1, then those limitations shall apply. <br />If this wastewater is combined with post mining reclamation area wastewater, then these limitations apply to the <br />combined discharge. If the post mining wastewater is separate, then the following limitations apply. Discharges of mine <br />drainage from underground workings of underground mines which are not commingled with discharges eligible for <br />alternate limitations set forth in this section shall in no event be eligible for the alternate limitations set forth in this <br />section. <br />:~ <br />• <br /> <br />