HYDRO20461

• Permit No: C1980001
• IBM Index Class Name: Hydrology
• Doc Name: COLOR DISCHARGE PERMIT SYSTEM CDPS RATIONALE AMENDEMENT 1
• Permit Index Doc Type: NPDES
• Media Type: D
• Archive: No

PART I
Page ix
Permit No. CO-0032638
B. MOMTORING REQUIItEMENTS
3. Acute WET Testing - Outfalls 004 and 007
a. Testing and Reporting Requirements
Tests shall be done at the (requency listed in Pan I.B.I. Test results shall be reported along with the Discharge
Monitoring Report (DMR) submitted for the reporting period during which the sample was taken. (i.e., WET testing
results for the first calendar quarter ending March 31 shall be reported with the DMR due April 28.) The results
shall be submitted on the Acute Toxicity Test report form, available from the Division. Copies of these reports are
to be submitted to both the Division and EPA along with the DMR.
The permittee shall conduct an acute 48-hour WET test using Ceriodaphnia sp., and an acute 96-hour WET test
using fathead mitmows. Acute tests will be replacement static tests of a single effluent grab sample. The permittee
shall conduct each acute WET test in general accordance with methods described in Methods for Measuring the
Acute Toxicitv of EfFluents and Receiving Waters to Freshwater and Mazine Organisms, EPA/600/4-90/027 or the
most current edition, except as modified by the most current Division guidance document entitled Guidelines for
Conducting Whole Effluent Toxicitv Tests.
b. Failure of Test and Division Notification
An acute WET test is failed whenever the LCD, which represents an estimate of the effluent concentration which is
lethal [0 50% of the test organisms in the time period prescribed by the test, is found to be less than or equal to
100% effluent. The permittee must provide written notification of the (allure of a WET test to [he Division, along
with a statement as to whether the Preliminary Toxicity Incident ("PTl")/Toxicity Identification Evaluation ("TIE")
investigation or accelerated testing is being performed (see nett section). Notification must be received by the
Division within 14 calendar days of the demonstration of acute WET in the routine required test.
"Demonstration" (or the purposes of Parts I.A.4(b),(c),(d) and (f) means no later than the last day of the laboratory
test.
c. Automatic Compliance Schedule Uoon Failure of Test
If a routine acute WET test is failed, regardless of whether the limit is in effect, the following automatic compliance
schedule shall apply. As part of this the permittee shall either:
(i) proceed to conduct the PTI/TIE investigation as described in Pan I.A.4.(d), or
ii) conduct accelerated testing using the single species found to be more sensitive.
if accelerated testing is being performed, the permittee shall provide written notification of the results within
14 calendar days of completion of the "Pattern of Toxicity"/"No Toxicity" demonstration. Testing will be at
least once every two weeks for up to five tests until 1) two consecutive tests fail or three of five tests fail, in which
case a pattem of toxicity has been demonstrated or, 2) two consecutive tests pass or three of five tests pass, in
which case no pattem of toxicity has been found. If no pattem of tonicity is found the tonicity episode is considered
[o be ended and routine testing is to resume. If a pattem of toxicity is found, a PTl/TIE investigation is to be
performed. If a pattem of toxicity is not demonstrated but a significant level of erratic toxicity is found, the
Division may require an increased (requency of routine monitoring or some other modified approach.
See Part i.C. for Definitions. Amendment No. I Issued Effective