HYDRO29431

• Permit No: M1977300
• IBM Index Class Name: Hydrology
• Doc Date: 10/6/1981
• Doc Name: SUMMARY OF RATIONALE COTTER CORP SCHWARTZWALDER MINE
• Media Type: D
• Archive: No

COLORADO DEPARTMENT OF HEALTH
Water Quality Control Division
Summary of Rationale Page 3
Permit Numoer: CO-00001244
EFFLUENT LIMITATIONS AND RATIONALE: (continued)
Parameter Average Range
Flow .63 nGD .43-.89
TSS (daily max.) 24 mg/1 16-33
Barium .085 mg/1 <.Ol-.2
Total Cadmium .013 mg/1 <.O1-.03
Total zinc .015 mgll <.O1-.03
Total Arsenic .Ol mg/1 <,001-.02
Total Radium 226 1.78 pCi/1 0.1-13.0
Total Uranium 2.42 (1635 pCi/1j 1.27-5.17
Sulfate 797 769-825
Gross Alpha 1047 pCi/I 720-1420
Total Molydenum .75 mg/1 .51-.88
Total Lead .04 mg/1 <.O1-.10
Total Iron .59 mg/I .03-I.10
The self monitoring data show the possibility of cadmium and lead levels exceeding
water Duality standards for Ralston Creek. Uranium levels, when converted to pico-
curies per litre do not meet the 1+0 pCi/1 standard set by the Water Quality Control
Commission. However, a temporary modification is in effect fora period of one year
after the effective date of the stream standards, May 16, 1981, for Uranium, lead
and copper. Under these modifications, the Uranium standard is existing quality of the
mine effluent, the copper concentration is 0.5 ma/i, the lead concentration is 0.05 mg/1
and cadnium level is O.Oj mg/l. Uranium levels in the permit must reflect the 2 mg/1, 4
mg/1 Federal 9.T limitations anc thus cannot be "Existing Levels".
In addition to the self monitoring data, [he permittee has submitted a one-time analysis
of parameters through the consolidated permit application. A review o~ Che parameters
analyzed indicates that cadmium, nickel, boron and selenium concentrat'ons may exceed
stream standards. Also, the detection limit for silver was above streaim standard
limits and could be a ;.roblem. Monitoring over a one year period will be required
for nickel, boron, seleniun and silver in order to determine the range of values.
Samples will be taken on a monthly basis. If high levels are still indicated a
compliance schedule will be developed and the permit will be modified.
A compliance schedule on page 7 of the permit will be followed to meet effluent
limits for ccoper, leas, cadmium and uranium. Levels to be reached at the end of the
schedule .ail', he those necessar, to meet the South Platte River Streams Standards.
The monitoring study and the modir"led parameters should be considered in one study.
The following table shows the effluent limitations and rationale for [his permit.