HYDRO30314 - Laserfiche WebLink

Home Browse Search

`~~~ UNITED STATES ENVIRONi41ENTAL PROTECTION AGENCY faEalON 8 9B8 ta'" STREET - sUfTE 306 DENVER, CO 8()202-260 http:lhvww.epa. govlreg ionCB Rtf: 8P-W-•P J. David Holm. Director Water Quality Control Division Colorado Department of Public Health and E::viron-nent 4300 Cherry CrrJt Drive South Denver, Colorado 80246-1530 Dear Mfr. Holm: This letter constitutes EPA's wmments on the issuance os'draft or proposed CDPS Permit Number CO-0045675 t o Batt{e Mountain Resources, ]nc. EPA Region VIII received the draft permit on March 31, 2000. At this time, EPA does not believe the draft permit and rationale contain suffdent information to demonstrate the proposed eElluent limitations and(or controls (BIvIPs) ensure ttsat water quaiity standards in the Rito Seco will be met for the discharges from Outfalls OOl and 002. Our genera! concerns are in regard to baseline water quality data used in the antidegradation analysis, lack of specitc numeric effluent limits for iron and manganese for Outfall 002, and potemially other appropriate numeric water quality based e$]uent limitations at Outfall 002, and in addition, the lack of limitations andlor specific controls For aluminum in the discharges from Outfalls 00] and 002. Our concerns are outlined below: Water~ality Data in the Antidegradation Analysis: ]t appears that the baseline water quality data used in the anti-degradation review for developing e$iuertt limitations far Outfail 001 was from station RS•5. RS-5 is approximately 2 miles downstream from the West Pit Outfal! 002 and an additional historic mining impacted area called the "Earth Science Pit". EPA belie>,T>s a more appropriate baseline water quality condition would be derived from station RS-l which is approximetely 2 miles upstream of the Battle Mountain mining activity. The CDPJ-?E rationale for using this data is that there are numerous tributaries entering the Aito Seco between RS-] and RS-S and that these tributaries more accurately reflect the influencesa of the na:uraI geology near the site. EPA believes these tributaries are corrtained within the Battle Mountain permit boundary and additional flow from the Earth Science Pit contn'butes metal load to this stream. In this respect, EPA does not believe tl;e influences are completely attributable to natural geologic conditions Furthermore, the baseline hardness value utilized for the calculating the water quality ~HNfeA on Reeyoled Paper