HYDRO25324

• Permit No: M1988112
• IBM Index Class Name: Hydrology
• Doc Date: 12/22/2000
• Doc Name: MEMO NOTICE OF ISSUANCE OF THE PERMIT FOR BATTLE MTN GOLD CO-0045675
• From: CDPHE
• To: ATTENDEES AT THE PUBLIC MEETING ON THE BATTLE MTN PERMIT CO-0045675
• Media Type: D
• Archive: No

Page 2'
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale -Page 21 Pennlt No. CO-0045675
Mercury, Total 0.000050 g/ 0.000010 0.000010 g/ 0.000010 ' g/
VI.B.4. Discussion o(Effluent Limitations (Cont.)
(d) Antidegradation Review: (Cont.)
Table VI-3 -Summa of Mass Balance Calculations - Out(all 001b 250 m discha a Bow Conf.
' " ' Antldegrada8on-Based'
Upstream " Segment 28 ~ Antldegradaflon- ~~ 8/or WQSBesed #
AmblerR Mann WaterQualiry Std ~ " Based WQS ji E(duent Cgncerrbafion
Parameter ~~ Concentration ii Acufe/Chronlc ~~ Atufa/Chronlc AarfelChronic
S (mg?) .. (M7) !y I ; (M3) Br (M3) (~)
Nickel, Potentially Dissdved 0.00050 g/ O.6fiCW.068 0.011 2.2#/0.043'
Radium 226+228, Total, pCi/1 0 y 5.0 5.0 g/ 5.0 • gr
Selenium, Total 0.00050 g/ 0.010 (Acute) 0.00193 0.0053 '
Silver, Potentially Dissolved 0.00010 g/ 0.00094/0.000030 0.000030 g/ 0.00029#/0.000030'g/
Uranium, Total Natural 0 fY 1.5'D.92 0.92 g/ 4.9#/0.92' g/
Zinc, Potentially Dissolved 0.0025 g/ 0.08CY0.073 0.014 0.26#/0.051'
fl/ = The single indicated standanis indicated in this column are chronic standards unless otherwise indicated.
L/ _ '0' is assumed to be zem: the mean was below the minimum defection level for these indicated parameters.
tl = For the metals parameters indicated as dissolved or potentially dissolved, the ambient mean (or these parameters is for the
dissolved Iracfion.
g/ = Presently !here is eilherno data orinadequete data collected to evaluate the instream concenlratlon /or these parameters.
Wdh addi8onar data, these calculations will be reevaluated. For the present time, the upstream levels are assumed to equal
zem.
g/ = Since these ambient upstream concentrations wen; below the minimum levels of defection, the M1 value represents one-halt
o/the minimum level of detecion.
(/ = Since the baseline loading at Station RS-5 is greater than or equal to the segment 28 wafer quality standard, the
an8degredatlon-based standard and antldegredatlon-based limitaton will revert fo the more stdngent value that is equal to the
wafer quality standard.
g/ = Since eHher there is not enough instream data collected, or the instreem data is less Then the minimum detection level which
is greater than the segment 28 wafer quality standard, the anfidegredatlon-based standard end an8degreda8on-based
limitation will revert to the morn stringent value that is equal to the wafer quality standard.
One additional consideration for an8degredation reviews is that if a determination has been made in
accordance with section 31.8(3)(c) that a proposed activity is likely to result in significant degradation of
reviewable waters, a determination shall be made pursuant to this sec8on whether the degradation is
necessary to accommodate important economic or social development in the area in which the waters are
located. The Division's evaluation shows that, based on available data, the resulting
antidegredation-based effluent limitations are determined to be reasonably related to the economic,
environmental, public health, and energy impacts to the public and affected persons. 1(the permittee
disagrees with this finding and/or determines that the proposed antidegredation-based limits can not be
attained wHh the proposed treatment or other relevant treatment technology, pursuant to section
31.8(3)(c) of the Basic Standards and Methodologies (or Surface Wafer, the permittee should submit all
pertinent information to the Division during the public notice period.
d) Determination o(Paremeters Limded (orThis Permit
Metals and /nopanics Limitations: For determining which metals and inorganic parameters will6e limited
in this permit, the Division evaluated the contributing wastewater sources that are being treatetl and then
will be discharged. A summary of these hvo contributing sources, which includes the Pit Backrll source
and the Alluvial Pumping wells source, are included in Appendix A. The permi[tee has estimated that the
prt backfill water conMbutes approximately 75 % o(the sources to be collected and treated, and the
alfuvla/ well water is approximately 25 %. In addition, data from a previously identified source, the