2011-06-17_PERMIT FILE - C1981018

• Permit No: C1981018
• IBM Index Class Name: Permit File
• Doc Date: 6/17/2011
• Doc Name: Water Discharge Permit
• Section_Exhibit Name: Illustration 46
• Media Type: D
• Archive: No

PART I
Page No. 10
Permit No.: CO- 0038024
toxicity has been demonstrated or 2) two consecutive tests pass or three of five tests pass, in which case no pattern of
• toxicity has been found. If no pattern of toxicity is found the toxicity episode is considered to be ended and routine
testing is to resume. If a pattern of toxicity is found, a PTI /TIE investigation is to be performed. If a pattern of toxicity is
not demonstrated but a significant level of erratic toxicity is found, the Division may require an increased frequency of
routine monitoring or some other modified approach.
d. PTI /TIE
The results of the PTI/TIE investigation are to be received by the Division within 120 days of the demonstration
of chronic WET in the routine test as defined above, or if accelerated testing is performed, the date the pattern of
toxicity is demonstrated A status report is to be provided to the Division at the 30, 60 and 90 day points of the
PTI/TIE investigation. The Division may extend the time frame for investigation where reasonable justification exists.
A request for an extension must be made in writing and received prior to the 120 day deadline. Such request must
include a justification and supporting data for such an extension.
The permittee may use the time for investigation to conduct a PTI or move directly into the TIE. A PTI consists of a
brief search for possible sources of WET, which might reveal causes of such toxicity and appropriate corrective actions
more simply and cost effectively than a formal TIE. If the PTI allows resolution of the WET incident, the TIE need not
necessarily be conducted. If, however, WET is not identified or resolved during the PTI, the TIE must be conducted
within the allowed 120 day time frame.
Any permittee that is required to conduct a PTI /TIE investigation shall do so in conformance with procedures identified
in the following documents, or as subsequently updated: 1) Toxicity Identification Evaluation:- Characterization of
Chronically Toxic Effluents, Phase I, EPA/600 /6- 91/005F May 92, 2) Methods for Aquatic Toxicity Identification
Evaluations Phase 1 Toxicity Characterization Procedures, EPA/600 /6- 91/003 Feb. 91 and 3) Methods for Aquatic
Toxicitv Identification Evaluations Phase II Toxicity Identification Procedures, EPA/600/3- 88/035 Feb. 1989.
• A fourth document in this series is Methods for Aquatic Toxicity Identification Evaluations Phase III Toxicity
Confirmation Procedures, EPA/600 /3- 88/036 Feb. 1989. As indicated by the title, this procedure is intended to confirm
that the suspected toxicant is truly the toxicant. This investigation is optional.
Within 90 days of the determination of the toxicant or no later than 210 days after demonstration of toxicity, whichever is
sooner, a control program is to be developed and received by the Division. The program shall set down a method and
procedure for elimination of the toxicity -to acceptable levels.
e. Request For Relief
The permittee may request relief from further investigation and testing where the toxicant has not been determined and
suitable treatment does not appear possible. In requesting such relief, the permittee shall submit material sufficient to
establish the following:
L It has complied with terms and conditions of the permit compliance schedule for the PTI/TIE investigation and other
appropriate conditions as may have been required by the WQCD;
ii. During the period of the toxicity incident it has been in compliance with all other permit conditions, including, in the
case of a POTW, pretreatment requirements;
iii. During the period of the toxicity incident it has properly maintained and operated all facilities and systems of
treatment and control; and
iv. Despite the circumstances described in paragraphs (i) and (iii) above, the source and/or cause of toxicity could not be
_ ._
located or resolved.
• If deemed appropriate by the Division, the permit or the compliance schedule may be modified to revise the ongoing
monitoring and toxicity investigation requirements to avoid an unproductive expenditure of the permittee's resources,
provided that the underlying obligation to eliminate any continuing exceedance of the toxicity limit shall remain.