2002-05-13_PERMIT FILE - C1981018 ‎(2)‎

• Permit No: C1981018
• IBM Index Class Name: Permit File
• Doc Date: 5/13/2002
• Doc Name: Please Refer to Illustration 46 for Water Discharge Permit
• Section_Exhibit Name: Illustration 13
• Media Type: D
• Archive: No

COLORADO DEPARTMENT OF NEALTN, Water Quality Control Division
Rationale - Page 4. Permit No. CO-0038024.
VI. TERMS AND CONDITIONS OF PERMTT
Table VI-1 -- Effluent Limits - Outfall 024
Parameter Limit
Floe, MGD Report al
TSS, mg/1 35/70 b/
pH, s.u. 6.5-9,0 c/
011 and Grease, mg/1 10 3/
Total Dissolved Solids, mg/1 Report d/
Total Iron, mg/1 3.5/7.0 b/
Whole Effluent Tonicity, Acute Report 3/
a/ 30 Day Average
Ti/ 30-Day Average/Daily Maximum
c/ Minimum-Mazim~
d/ Daily Maximum
Rationale
NA
Beat Practicable Technology
Water Quality Standards
State Effluent Regulations
Salinity Regulations
Beat Available Technology
See Discussion
1. Discussion of Limitations: Although there was no effluent from the
new discharge point available, the permittee submitted monitoring
data from 023, which is expected to be similar. No problems were
noted in the data, ezcept for oil and grease, which had a level of
25 mgll. The permittee explained that this was due to a problem
with an emulsion return surge tank. The situation has been
remedied by removal of a faulty in-line return pump, as well as
through better employee education. However, submittal of results
from a grab sample for oil and grease on a monthly basis will now
be required, in order to ensure that the problem does sot recur.
This monitoring will also be required for the ezisting discharge.
point 023, since that is where the original sample was taken.
2. Whole Effluent Tonicity (WET) Testing: For 024, acute WET testing
is required. (See Parts I.A and I.b of the permit.) Monitoring
shall be performed commencing vith the first full calendar quarter
following the amendment effective sate.
a) Purpose of WET Testing: For a complete discussion of WET
testing, see the previous Rationale, dated October 14, 1988.
b) Instream Waste Concentration (IWC): As a condition of the
permit, the permittee will be required to conduct routine
monitoring for acute toxicity. Acute tonicity occurs :,=aen there
is a statistically significant difference is the mortality
observed, for Ceriodaohnia sp. (water flea) and fathead minnows,'
between the control and any effluent concentration. Should

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