Laserfiche WebLink
Mountain Coal and Beaz Coal Water Quality Assessment CO-0038776 and CO-0044377 <br />Table A-5 <br />TVS-Based Metals Water Quality Standards for Sylvester Gulch, West Sylvester Gulch, <br />the Dry Fork of Minnesota Creek, and Lone Pine Gulch <br />Based on the Table Value Standazds Contained in the Colorado Department of Public Health <br />and Environment Water Quality Control Cormission Re lation 35 <br />Calculated Using the Following V slue for Hazdness as CaCO3: 400 mg/I <br /> Zn-Stream Neater ~ <br />Parameter <br />,; : °. uah . <br />Q __ ty`Standard : <br />Far`mula l'lsedx <br /> <br />i <br />l <br />C <br />d <br />Di Acnte 19 llg/l [1.li667-0.041841n(harduess)][e (1'128(ln(hardness)}3.6867)] <br />um, <br />sso <br />ved <br />a <br />m , <br />d <br /> ChIOIllC 6.2 ~ug/1 ness)}2.715)] <br />[1.10167-0.041641n(hardness)][e (o.7852(In(bar <br />Hexavalent Chromium, Acnte 16 U Numeric standards provided, fo=mnla not applicable <br />Dissolved ChpOIllC 11 llg/1 Numetc standards provided, fomwla not applicable <br /> Acute 50 ug/1 e (o.94zz(]n(hardness>}1.7aos) <br />Di <br />l <br />d <br />C <br />ve <br />opper, <br />sso Chronic 29 ug/1 e(o.asaspn(bataness)}t.7aza) <br /> Acute 4738 ug/1 e(0.3331(ln(hardness)}+6.4676) <br />Manganese <br />Chronic <br />2618 u 1 (0.3331(]n(hardness)}+5.8743) <br />e <br /> <br />i Acute 1.513 ug/1 e (osa6(m(naraness)~zas3) <br />Nickel, D <br />ssolved <br />ChI01]IC <br />~ 168 llg/1 <br />~ e (0.846(]n(hardness)}+0.0554) <br />Selenium, Dissolved Acute 18 ug(1 Numeric standardsprovided, fommla trot applicable <br /> <br />l <br />Di <br />l <br />d Acute 22 ug/1 '/: e (1.72(In(hardness)}6.52) <br />ve <br />ver, <br />sso <br />Si Chronic 3.5 ug/I e (1.7z(ln(hazdness)}9.o6) <br /> Acute 379 ug/1 e(0.8473(ln(hazdness)}F0.8618) <br />Di <br />l <br />d <br />ve <br />sso <br />Zinc, ChIOmC 382 Ug/1 e (0.8473(ln(hardness)}+0.8699) <br />Ambient Water Quality <br />The WQCD evaluates ambient water quality based on a variety of stafistical methods as prescribed in <br />Section 31.8(2)(a)(i) and 31.8(2)(b)(i)(B) of the Colorado Department of Public Health and <br />Environment Water Quality Control Commission Regulation No. 31. Ambient water quality is <br />evaluated in this WQA for use in determining assimilative capacities and in completing <br />antidegradation reviews for pollutants of concern. <br />North Fork of the Gunnison ?liver: To conduct an assessment of the ambient water quality of the <br />North Fork ofthe Gunnison River upstream of the Mountain Coal and Bear Coal W WTFs, data were <br />gathered from USGS water quality station 09132500 (North Fork of the Gunnison River near <br />Somerset, CO) and from the permittee's Upper North Fork station, both located at the same point <br />approximately 1 mile upstream from the neazest tiischazge. Data for the USGS station were available <br />for a period of record from October 1996 through August 2001, except for total ammonia and total <br />chromium data, for which recent data were not available. Thus, historical data for a period ofrecord <br />from October 1977 through August 1982 were used. Data from the permittee's Upper North Fork <br />Appendix A Page 8 of 20 Last Revised 3/9/2004 <br />