§ 21-68. Affirmative defenses to discharge violations.

(a) Upset.

(1) For the purpose 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 preventative maintenance, or careless or improper operation. 
(2) An upset shall constitute an affirmative defense to an action brought for noncompliance with categorical pretreatment standards if the requirements of paragraph (3) are met. 
(3) An industrial user who wishes to establish the affirmative defense of upset shall demonstrate, through properly signed, contemporaneous operating logs, or other relevant evidence that: 

a. An upset occurred and the industrial user can identify the cause(s) or the upset. 
b. The facility was at the time being operated in a prudent and workmanlike manner and in compliance with applicable operation and maintenance procedures. 
c. The industrial user has submitted the following information to the WWTP and treatment plant operator 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]: 

(i) A description of the indirect discharge and cause of noncompliance. 
(ii) The period of noncompliance, including exact dates and items or, if not corrected, the anticipated time the noncompliance is expected to continue. 
(iii) Steps being taken and/or planned to reduce, eliminate and prevent recurrence of the noncompliance. 

(4) In any enforcement proceeding, the industrial user seeking to establish the occurrence of an upset shall have the burden of proof. 
(5) 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. 
(6) The industrial user shall control production of 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 facility is reduced, lost or fails. 

(b) General/specific prohibitions. An industrial user shall have an affirmative defense to an enforcement action brought against it for noncompliance with the general and specific prohibitions in section 21-59 (a) of this ordinance if it can prove that it does not know or have reason to know that its discharge, along or in conjunction with discharges from other sources, would cause pass through or interference and that either: (a) a local limit exists for each pollutant discharged and the industrial user was in compliance with each limit directly prior to, and during, the pass through or interference, or (b) 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 in the case of interference, was in compliance with applicable sludge uses or disposal requirements. 
(c) Bypass.

(1) For the purpose of this section. 

(i) "Bypass" means the intentional diversion of waste streams from any portion of an industrial user's treatment facility. 
(ii) "Severe property damage" means substantial physical damage to property, damage to the treatment facilities which causes them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass. Severe property damage does not mean economic loss caused by delays in production. 

(2) 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 or assure efficient operation. These bypasses are not subject to the provision of paragraphs (3) and (4) of this [sub]section. 
(3) Bypass notifications. 

(i) If an industrial user knows in advance of the need for a bypass, it shall submit prior notice to the Superintendent, at least ten (10) days before the date of the bypass if possible. 
(ii) An industrial user shall submit oral notice of an unanticipated bypass that exceeds applicable pretreatment standards to the WWTP 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 reoccurrence of the bypass. The WWTP Superintendent may waive the written report on a case-by-case basis if the oral report has been received within twenty-four (24) hours. 

(4) Bypass is prohibited, and the WWTP may take action against an industrial user for bypass, unless; 

a. Bypass was unavoidable to prevent loss of life, personal injury, or severe property damage. 
b. 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 preventative maintenance; and 
c. The industrial user submitted notices as required under paragraph (2) of this [sub]section. 

1. The Superintendent may approve and anticipate bypass, after considering its adverse effects, if the Superintendent determines that it will meet the three conditions listed in paragraph (4)a.—c. of this [sub]section.

(Ord. No. 2022-49, § 1, 11-01-22)