REP42616

• Permit No: C1981008
• IBM Index Class Name: Report
• Doc Date: 12/11/2001
• Doc Name: NUCLA NPDES PERMINT CO-0000213
• Permit Index Doc Type: HYDROLOGY REPORT
• Media Type: D
• Archive: No

PART I
Page if of 19
Permit No. CO-0000213
B. MONITORING REQUIREPfENTS
2. Frequency and Sample Type - Acute WET Testing - Outfalls 001 and 006
The monitoring frequency for acute WET tests shall be quarterly,
commencing with the first full calendar quarter following the permit
effective date. Quarterly test results shall be repotted along with the
Discharge Monitoring Report (DMR) submitted for the end of the reporting
calendar quarter (i.e., WET testing results for the calendar quarter
ending March 31 shall be reported with the DMR due April 28, with the
remaining WET testing reports submitted with DMRs due each July 28,
October 28 and January 28). The results shall be submitted on the
Acute Tonicity Test report form, available from the Division. Copies
of these reports are to be submitted to both the Division and EPA.
The permittee shall conduct each acute WET test in general accordance
with methods described in the Division guidance document entitled
Guidelines for Conducting Whole Effluent Toxicity Tests. The permittee
shall conduct an acute 48-hour WET test using Ceriodaphnia sp., and an
acute 96-hour WET test using fathead minnows. Acute tests will be
replacement static tests of a single effluent grab sample.
• 3. decelerated Testing
If an individual tonicity test shows tonicity at concentrations less
than or equal to the Instream Waste Concentration (IWC) of 3L: or if
SOX species mortality in any dilution is detected in any acute WET test
conducted in accordance with this permit, the permittee shall notify
the Division verbally within 24 hours and is writing within 5 days of
becoming aware of the toxicity. Within 7 days of becoming aware of the
to~city, the permittee shall then begin accelerated testing of the
discharge with whichever species has proven (through the first instance
of toxicity) to be the most sensitive. The permittee will continue
such testing with one species, once every week until directed by the
Division to do otherwise, but in no case for more than five
representative tests.
4. Preliminary To~.city Investigation
If directed by the Division, the permittee shall perform a preliminary
tonicity investigation. The permittee will have 15 working days from
the date of Division notification to complete a preliminary tonicity
investigation and submit the results to the Division, in writing. The
preliminary toxicity investigation may Snclude, but is not limited to:
additional chemical and biological monitoring, examination of
pretreatment program records, examination of discharge monitoring
reports, evaluation of treatment processes and chemical use, inspection
. of material storage and transfer areas to determine if a spill may have
occurred, and similar procedures.
Revised 5/2/89