Affirmative Defenses to Discharge Violations
A. For the purposes of this Section, "upset" means an exceptional incident in which
there is unintentional and temporary noncompliance with categorical pretreatment
standards because of factors beyond the reasonable control of the industrial user.
An upset does not include noncompliance to the extent caused by operational error,
improperly designed treatment facilities, inadequate treatment facilities, lack
of preventive maintenance, or careless or improper operation.
An upset shall constitute an affirmative defense to an action brought for noncompliance
with categorical pretreatment standards if the industrial user demonstrates, through
properly signed, contemporaneous operating logs, or other relevant evidence that:
1. An upset occurred and the user can identify the cause(s) of the upset; and,
2. The facility was at the time being operated in a prudent and workman-like manner
and in compliance with applicable operation and maintenance procedures; and,
3. The industrial user has submitted the following information to the Director within
twenty four (24) hours of becoming aware of the upset (if this information is provided
orally, a written submission must be provided within five (5) days):
a. A description of the indirect discharge and cause of noncompliance; and,
b. The period of noncompliance, including exact dates and times or, if not corrected,
the anticipated time the noncompliance is expected to continue; and,
c. Steps being taken and/or planned to reduce, eliminate and prevent recurrence
of the noncompliance.
In any enforcement proceeding, the industrial user seeking to establish the occurrence
of an upset shall have the burden of proof. Industrial users will have the opportunity
for a judicial determination on any claim of upset only in an enforcement action
brought for noncompliance with categorical pretreatment standards.
The industrial user shall control production or all discharges to the extent necessary
to maintain compliance with categorical pretreatment standards upon reduction, loss,
or failure of its treatment facility until the facility is restored or an alternative
method of treatment is provided. This requirement applies in the situation where,
among other things, the primary source of power of the treatment is reduced, lost,
B. An industrial user may allow any bypass to occur which does not cause pretreatment
standards or requirements to be violated, but only if it also is for essential maintenance
to assure efficient operation. These bypasses are not subject to the provisions
below. If an industrial user knows in advance of the need for a bypass, it shall
submit prior notice to the Director, at least ten (10) days before the date of the
bypass, if possible.
An industrial user shall submit oral notice of an unanticipated bypass that exceeds
applicable pretreatment standards to the POTW within twenty four (24) hours from
the time it becomes aware of the bypass. A written submission shall also be provided
within five (5) days of the time the industrial user becomes aware of the bypass.
The written submission shall contain a description of the bypass and its cause;
the duration of the bypass, including exact dates and times, and, if the bypass
has not been corrected, the anticipated time it is expected to continue; and steps
taken or planned to reduce, eliminate, and prevent recurrence of the bypass. The
Director may waive the written report on a case-by-case basis if the oral report
has been received within twenty four (24) hours.
Bypass is prohibited, and the Director may take enforcement action against an industrial
user for a bypass, unless:
1. Bypass was unavoidable to prevent loss of life, personal injury, or severe property
2. There were no feasible alternatives to the bypass, such as the use of auxiliary
treatment facilities, retention of untreated wastes, or maintenance during normal
periods of equipment downtime. This condition is not satisfied if adequate back-up
equipment should have been installed in the exercise of reasonable engineering judgment
to prevent a bypass which occurred during normal periods of equipment downtime or
preventive maintenance; and,
3. The industrial user submitted notices as required under this paragraph "B".
The Director may approve an anticipated bypass, after considering its adverse effects,
if the Director determines that it will meet the three conditions listed above.
C. An industrial user shall have an affirmative defense to an enforcement action
brought against it alleging a violation of the general prohibition established in
Section 7.06.005, paragraph "A.1", and the specific prohibitions in Section 7.06.005,
paragraphs "A.4", "A.1O", "A.11", "A.16", and "A.17", where the industrial user
can prove that it did not know or have reason to know that its discharge, alone
or in conjunction with a discharge or discharges from other sources, would cause
pass through or interference; and that either:
1. A permit limit or Specific Pollutant Limitation designed to prevent pass through
and/or interference, as the case may be, was developed by the Director for each
pollutant in the industrial user's discharge that caused pass through or interference,
and the industrial user was in compliance with each such permit limit or Specific
Pollutant Limitation directly prior to and during the pass through or interference;
2. If no permit limit or Specific Pollutant Limitation has been developed for the
pollutant(s) that caused the pass through or interference, the industrial user's
discharge directly prior to and during the pass through or interference did not
change substantially in nature or constituents from the industrial user's prior
discharge activity when the POTW was regularly in compliance with the POTW's NPDES
permit requirements and, in the case of interference, was in compliance with applicable
sludge use or disposal requirements.
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