HYDRO21737

• Permit No: M1977306
• IBM Index Class Name: Hydrology
• Doc Date: 6/23/2005
• Doc Name: water sampling reports
• From: cotter
• To: dmg
• Media Type: D
• Archive: No

COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Amendment No. 1 -Rationale -Page 2, Permit No. CO-0036251
F. Discharge Point: 001 from Mine JD-7: Discharges to an unnamed tributary which flows in a northerly
direction to East Paradox Creek, then approximately 8 miles to the Dolores River. The
total distarzcefrom 001 to the Dolores River is approximately 12. S miles.
38° 14.39 north, /08° 45.07 west.
002 from Mine JD-9: Discharges to an unnamed tributary to Fawn Springs, which goes
to Bull Canyon then to the Dolores River. The total distance from discharge point 002 to
the Dolores River is approximately 10.5 miles.
38° 12.47 north, 108° 47.36 west.
Except during major storm events, the two discharges do not reach the receiving waters
of East Paradox Creek or Bull Canyon, tributaries to the Dolores River.
G. Facility Flows: 001 Desien Flows: 0.2 MGD =Maximum Flow
002 Desi¢n Flows: 0.3 MGD =Maximum Flow
H. CDMGPermitNo.: JD-7.• M-77-308
JD-9: M-77-306
III. RECEIVING STREAM-Identification andClass~cations
Both the JD-7 Mine and the JD-9 Mine discharge to unnamed tributaries (Segment 4) that eventually flow to the Dolores River
(Segment 2), Lower Dolores River Sub-basin, Lower Dolores River Basin. Segment 4 is classified for thefollowing uses: Use
Protected, Recreation Class 2, Aquatic Life Class 2 Warm, and Agriculture. The downstream segment for the Dolores River
(Segment 2) is classified for the following uses: Recreation Class I, Aquatic Life Class I Warm, and Agriculture.
-" PURPOSEOFAMENDMENT
Thrs amendment request for the Cotter JD-7 and JD-9 Mines was received in a letter dated January 20, 2003 from Glen Williams
of Cotter Corporation. !n this letter, it was pointed out that the renewalpermit, issued on December 30, 2002 and effective on
February 1, 2003, requires Cotter to sample Ra-228 monthly. Mr. Williams stated this increased monitoring would triple the
analytical load and costs for the facility since Isotopes Ra-226 & 218 each require d~erent analytical procedures. Cotter
requested that, based upon the previous permit, the monitoring frequency ofTatal Radium 228 be decreased from a monthly to a
quarterly basis.
[! DISCUSSIONOFAMENDMENT
As specked in an earh'er amendment to the last permit renewal, the request far a reduced Radium Z28 monitoring frequency was
based upon historical data collected at outfalls 001 and 002. The constituent Total Radium 228 represented only a small fraction
of the Total Radium 226+228 values at both discharge points. During the past 11 years, 456 Ra-228 samples were collected at
JD-7 and JD-9 (outfalls 001 and 002). The average value of Radium 228 recorded was 0.2 f 0.45 pCi/!, and the highest result
was 1.3 t 0.7 pCUI. As previously explained these two mines are located in a geological formah'on that contains very little
thorium (Th-132), and consequently there would be very little Radium 228, which is a daughter product of Thorium. Thus,
consistent with the previously amended permit, Cotter has requested that the monitortngfor Total Radium 228 be returned to a
quarterly frequency.
The Division has reviewed the request and has determined that this permit will be amended as requested. This is based upon
earlier discharge monitoring report data and the conditions in the previous permit. The data evaluated for the recent renewal of
this permit has shown no exceedances for the Total Radium 226+2281imits (S.0/10.0 pCi/1), with average and maximum reported
concentrations ranging from 0.84 to 2,4 pCi/l at outfall 002 for the period from August 2000 through Augus12002.
Ij[ater discharge monitoring data indicates an increase in concentration of Radium 228 such that the Total Radium 226+228
value would be above the permit limitations, then the Division would need to reevaluate the monitoring frequency for Radium 228
to determine ijthe frequency should be increased