(a)   Upset.
      (1)   "Upset" means an exceptional incident in which there is unintentional and temporary noncompliance with categorical pretreatment standards or local limits because of factors beyond the reasonable control of the 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.
      (2)   An upset shall constitute an affirmative defense to an action brought for noncompliance with categorical pretreatment standards or local limits if the requirements of paragraph (a)(3) hereof are met.
      (3)   A 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 user can identify the cause(s) of the upset,
         B.   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
         C.   The user has submitted the following information to the Superintendent within twenty-four hours of becoming aware of the upset. However, if this information is provided orally, a written submission must be provided within five days, including:
            1.   A description of the indirect discharge and cause of noncompliance;
            2.   The period of noncompliance, including exact dates and times or, if not corrected, the anticipated time the noncompliance is expected to continue; and
            3.   Steps being taken and/or planned to reduce, eliminate, and prevent recurrence of the noncompliance.
            4.   In any enforcement proceeding, the user seeking to establish the occurrence of an upset shall have the burden of proof.
            5.   Users shall control all discharges to the extent necessary to maintain compliance with categorical pretreatment standards or local limits upon reduction, loss or failure of its treatment facility until the facility is restored or an alternative method of treatment is provided.
   (b)   Prohibited Discharge Standards. A user shall have an affirmative defense to an enforcement action brought against it for noncompliance with the general prohibitions in Section 1046.04 or the specific prohibitions of this chapter if it can prove that it did not know, or have reason to know, that its discharge, alone or in conjunction with discharges from other sources, would cause pass through or interference and that either:
      (1)   A local limit exists for each pollutant discharge that caused pass-through or interference and the user was in compliance with each such limit directly prior to and during the pass through or interference; or
      (2)   No such 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 use or disposal requirements.
   (c)   Bypass.
      (1)   For the purpose of this section:
         A.   "Bypass" means the intentional diversion of waste streams from any portion of a user's treatment facility.
         B.   "Severe property damage" means substantial physical damage to property, damage to the treatment facilities of a user 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)   A 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 operation. These bypasses are not subject to the provisions of paragraph (c)(3) or (4) hereof.
      (3)   A.   If a user knows in advance of the need for a bypass, it shall submit prior notice to the Superintendent, at least ten days before the date of the bypass, if possible.
         B.   A user shall submit oral notice to the Superintendent of an unanticipated bypass that exceeds applicable pretreatment standards within twenty-four hours from the time it becomes aware of the bypass. A written submission shall also be provided within five days of the time the 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 Superintendent may waive the written report on a case-by-case basis if the oral report has been received within twenty-four hours.
      (4)   A.   Bypass is prohibited, and the Superintendent may take an enforcement action against a user for a bypass, unless:
            1.   Bypass was unavoidable to prevent loss of life, personal injury, or severe property damage;
            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 backup 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 user submitted notices as required under paragraph (c)(3) hereof.
         B.   The Superintendent may approve an anticipated bypass, after considering its adverse effects, if the Superintendent determines that it will meet the three conditions listed in paragraph (c)(4)A. hereof.
(Ord. 22C. Passed 4-15-96.)