Laserfiche WebLink
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division <br />Rationale, Page 3, COG-0850000 Coal Mining General Permit <br />Table III-2a: Effluent Limitations and Monitoring Requirements - Alkaline Drainage, Coal Preparation Plants and Coal <br />Preparation Plant Associated Areas and Western Alkaline Coal Mining (additional requirements apply to Western <br />Coal Mining, See Section H1 A.3 of this rationale) <br />Limitations <br />Parameter 30-pay 7-Day Daily Rationale Monitoring Sample <br />- Frequency 7}ape <br />`{.vg' , vg.` Afar. <br />General Permit Requirements <br />Flow, MGD Report NA Report Discharge Evaluation Continuous l <br />a <br />Instantaneous <br />pH, s. u. N/A NA 6.5-9.0 Water Quality Standards Weekly <br />Oil and Grease, mg11 N/A NA 10 State Effluent Regulations Weekly <br /> Federal Effluent Lim itation Guidelines <br />Total Suspended Solids, mg11 35 NA 70 Federal ELG Weekly <br />Total Iron, mg11 <br />Existing Sources (before 514184) 3.5 NA 7.0 Federal ELG Weekly <br />New Sources (after 514184) 3.0 NA 60 <br />Settleable Solids, ml/l Report NA 0.5 Federal ELG Weekly -R <br /> ---Site Specific Limitations <br />Total Dissolved Solids, mg11 • Report NA Report Salinity Regulations Quarterly 4 <br />Total Phosphorus (as P), mg11 Report NA Various Control Regulations Monthly <br />Total Recoverable Iron, ug/1 *** <br />Other Pollutants of Concern <br />Whole Effluent Toxicity (WET) <br />Chronic <br />Acute <br />1000 NA NA Water Quality Standards <br />Various NA Various Water Quality Standards <br />Stat Diff and IC25 > IWC State Permit Limitations <br />LC50 > 100% State Permit Limitations <br />Weekly <br />Weekly <br />Quarterly <br />Recorder / <br />In-situ <br />Grab <br />Visual 9 <br />Grab <br />Grab <br />Grab <br />Grab <br />Grab <br />Grab <br />Grab <br />3 Gra&7;ast <br />Grah <br />Footnotes 1-4, *, and *! See Footnotes under Table III-1 <br />- *** This limitation will apply and will substitutefor the 30-day average total iron limit based upon the ELG, when a total recoverable iron standard is applicable to the <br />dream segment. <br />Alternate Limitations For Alkaline Mine Drainage, Coal Preparation and Associated Areas and Western Alkaline Coal <br />Mining - Table 111-2b contains limitations for any discharge or increase in the volume of a discharge from an above ground <br />alkaline mine (or an underground alkaline mine where the effluent is commingled with other categorical wastewater prior to <br />discharge), caused by precipitation within any 24-hour period less than or equal to the 10-year, 14-hour precipitation event <br />(or snowmelt of equivalent volume) m substitute the following limitations for these speck parameters only, subject to <br />burden of proof requirements described in Part LB.4 of the permit. <br />Table III-2b .Alternate Effluent Limitations and Monitoring Requirements - Alkaline Drainage, Coal Preparation Plants and <br />Coal Preparation Plant Associated Areas and Western Alkaline Coal Mining (additional requirements apply to <br />Western Coal Mining, See Section 1H..A.3 of this rationale) <br />unutanons <br />30 ` 7-Day Daily Monitoring Sample <br />Parameter Rationale <br />Day Avg. Max. - Frequency t Type, <br />Federal Effluent Limitation Guidelines <br />Total Suspended Solids, mg11 Report NA Report Federal ELG Weekly Grab <br />Total Iron, mg/1 <br />Existing Sources (before 514184) Report NA Report Federal ELG Weekly Grab <br />New Sources (after 514184) Report NA Report <br />Alternate Limitations For Alkaline Mine Drainage, Coal Preparation and Associated Areas, and Western Alkaline Coal <br />Mining - Table III-2c contains limitations for any discharge or increase in the volume of a discharge from an above ground <br />alkaline mine (or an underground alkaline mine where the effluent is commingled with other categorical wastewater prior to <br />discharge), caused byprecipitation within any 24-hourperiod greater than the 10-year. 24-hour precfpitation event (or <br />snowmelt of equivalent volume) may substitute the following limitations for these specific parameters only, subject to burden <br />of proof requirements described in Part LB.4 of the permit.