HYDRO22809

• Permit No: C1981010
• IBM Index Class Name: Hydrology
• Doc Name: RATINALE FOR PUBLIC NOTICE
• Permit Index Doc Type: CORRESPONDENCE
• Media Type: D
• Archive: No

PART I
Page li of 19
Permit No. CO-0032115
B. MONTI~DRINO REQUIRFZffN1S
4. Acute WET Testing-Outfalls 001, 002. 005. 009. 011, 013, OLS. 016 and 017 (contirmed)
(d) PTI E
The results of the PTI/TIE irnesti¢atian are to be received by the Division within 120 days of
the demonstration of acute WEf in the routine test. as defined above, or if accelerated
testing is verfarmed, the date the oattern of toxiciri is demonstrated. A status report is to
be orovided to the Division at the 30. 60 and 90 day points of the PTI/TIE inrestigation. 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 pennittee may use the time for irnestigation 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 PfI, the TIE mist be
conducted within the allowed 120 day time frame.
Any permittee that is required to conduct a PCI/TIE investigation shall do so in conformance
with procedures identified in the following documents, or as subsequently updated: 1) Methods
for Aquatic Toxicity Identification Evaluations, Phase I Toxicity Characterization Procedures,
EPA/600/6-91/003 Feb. 91 and 2) Methods for Aquatic Toxicity Identification Evaluations Please
II Toxicity Identification Procedures, EPA/600/3-88/035 Feb. 1989.
A third document in [his 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) R~uest For Relief
The permittee may request relief from further irnestigation and testing where the toxicant has
not been determined and the Division has determined suitable treatment does not appear
possible. In requesting such relief, the pennittee shall submit material sufficient to
establish the following:
(i) It has complied with terms and conditions of the permit compliance schedule for the
PTI/fIE investigation and other appropriate conditions as may have been required by
the Division;
(ii) During the period of the toxicity incident it has been in compliance with all other
permit conditions, including, in the case of a POIW, pretreatment requirements;
Amendment 2 Issued 03/15/94 Effective 05/01/94
Amendment 3 Issued 07/08/94 Effective 09/01/94
Amendment 4 Issued Effective