§ 58-94. Affirmative defenses to discharge violations.

(a)

Upset. As used in this subsection, the term "upset" means an exceptional incident in which there is unintentional and temporary noncompliance with categorical pretreatment standards and requirements because of factors beyond the reasonable control of the industrial user. Noncompliance caused by operational error, improperly designed pretreatment facilities, inadequate treatment facilities, lack of preventive maintenance or careless or improper operation does not constitute an upset. An upset shall be an affirmative defense to an enforcement action brought against a user for violating a pretreatment standard and requirement of this article if the following conditions are met:

(1)

The user can identify the cause of the upset.

(2)

The facility was operating in a prudent and workmanlike manner at the time of the upset and was in compliance with applicable O & M procedures.

(3)

The user submits, within 24 hours of becoming aware of the upset, a description of the discharge and its courses, the period of noncompliance (if not corrected, then time noncompliance is anticipated to end) and the steps being taken to reduce, eliminate and prevent recurrence of the noncompliance.

(4)

If this report is given orally, the user must also submit a written report containing such information within five days, unless waived by the superintendent.

(b)

General and specific prohibitions. An industrial user shall have an affirmative defense to an enforcement action brought against the use for noncompliance with the general and specific prohibitions in section 58-131 if the user can prove that the user did not know or have reason to know that the discharge would cause pass through or interference and that either:

(1)

A local limit exists for each pollutant discharged, and the user was in compliance with each limit directly prior to and during the pass through or interference; or

(2)

No local limit exists, but the discharge did not change substantially in nature or constituents from the user's prior discharge when the city was regularly in compliance with its NPDES permit and, if interference occurred, in compliance with applicable sludge use or disposal requirements.

(c)

Bypass. The intentional diversion of waste streams from any portion of an individual user's treatment facility shall be an affirmative defense to an enforcement action brought against the industrial user if the user can demonstrate that such a bypass was unavoidable to prevent loss of life, personal injury or severe property damage. In order to be eligible for the affirmative defense, the industrial user must demonstrate that there was no feasible alternative to the bypass and submit notice of the bypass as required by 40 CFR 403.17.

(Ord. No. 91-4, §§ 13.1—13.3, 12-11-1991)