GENERAL41025

• Permit No: M1990041
• IBM Index Class Name: General Documents
• Doc Date: 6/29/1993
• Doc Name: COLO WASTEWATER DISCHARGE PERMIT SYSTEM CO-0043168 GOLDEN MILL JOINT VENTURE
• From: CDOH
• To: GOLDRUSH MINING CORP
• Media Type: D
• Archive: No

-
~:OLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
~ y Rationale - Page 9 Permit No. CO-0043168
a) Metals Limitations: (Cont.)
Table VI-2
Reported Concentration Calculated Effluent
Parameter in Mine Water Sample Concentrations (M2)

Pot. Dissolved Cadmium, mg/1 0. 012 (T. Rec.) 0.0019/0.0083
P.D. Hexavalent Chromium, mg/1 0. 009 (Total) 0.012/0.017
Potentially Dis. Copper, mg/1 2. 5 (T. Rec.) 0.068
Total Recoverable Iron, mg/1 28 5.7
Potentially Dis. Lead, mg/1 0. 013 (T. Rec.) 0.0099/0.27
Total Recov. Manganese, mg/1 8. 7 1.1
Total Mercury, mg/1 0. 0001 0.00001
Potentially Dis. Nickel, mg/1 0. 12 (T. Rec.) 0.53/7.2
Poc. Dis. Silver, mg/1 0. 0004 (T. Rec.) 0.00023/0.0062
Total Zinc, mg/1 2. 0 (T. Rec.) 0.75/1.5
The Division has also reviewed other metal and inorganic
parameters in the untreated mine water analysis, and determined
that these parameters do not need to be limited or continuously
monitored. Refer to the data for the other parameters in the
permit application section of the permit file.
5. Whole Effluent Toxicity ;WET) Testing: For this facility, both
acute and chronic WET testing are required for discharge point OU1.
See Parts I.A and I.B of the permit.
Purpose of WET Testing: Section 6.9.7 of the "Regulations for the
State Discharge Permit System", passed by the Water Quality Control
Commission (WQCC), has established the use of WET testing as a
method for identifying and controlling toxic discharges from
wastewater treatment facilities. WET testing is being utilized as
a means to ensure that there are no discharges "in amounts,
concentrations or combinations which are harmful to the beneficial
uses or toxic to humans, animals, plants, or aquatic life" as
required by Section 3.1.11 (1)(d) of the "Basic Standards and
Methodologies for Surface Waters".
Chemical analysis of effluent has provided only a partial
evaluation of the potential impact a discharge could have on the
receiving stream. Alse, chemical analysis cannot evaluate the
synergistic or antagonistic effect of compounds. There are also
compounds for which an accurate or reproducable method of chemical
analysis has not yet been developed, as well as compounds which are
just beginning to be evaluated for toxic effects. WET testing will
provide a more comprehensive means of evaluating the toxicity of a
discharge than could otherwise currently be accomplished.