(A) Upset.
(1) An upset shall constitute an affirmative defense to an action brought for non- compliance with pretreatment standards if the requirements of division (A)(2) below are met.
(2) A user who wishes to claim upset as a defense to its non-compliance shall have the burden of demonstrating, through properly signed, contemporaneous operating logs or other relevant evidence that:
(a) An upset, as defined herein, 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 workmanlike manner and in full compliance with applicable operation and maintenance procedures;
(c) The user has submitted the following information to the POTW Director within 24 hours of becoming aware of the upset (if this information is provided orally, a written submission must be provided within five days):
1. A description of the discharge and the cause of the non-compliance for which upset is claimed as a defense;
2. The period of non-compliance, including exact dates and times and, if not corrected, the anticipated amount of time the non-compliance is expected to continue; and
3. All steps being taken or planned or both to reduce, eliminate and prevent recurrence of the non-compliance.
(d) In any enforcement proceeding, the user seeking to establish the occurrence of an upset shall have the burden of proof;
(e) Users will have the opportunity for a judicial determination on any claim of upset only in an enforcement action brought for non-compliance with categorical pretreatment standards; and
(f) Users shall control production of all discharges to the extent necessary to maintain compliance with this chapter 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) Prohibited discharge standards defense. A user shall have an affirmative defense to an enforcement action brought against it for non-compliance with the general prohibitions in § 50.040 of this chapter or the specific prohibitions in § 50.041(B), (C), (E) through (G), and (I) through (AA) 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 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 town WWTP 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) Permitted bypass. 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 maintenance to assure efficient operation. These bypasses are not subject to divisions (C)(3) and (C)(4) below.
(2) Notice of bypass.
(a) Except in the case of emergencies, a user shall submit at least ten days’ prior notice to the POTW Director of need for the bypass.
(b) A user shall submit oral notice to the POTW Director of an unanticipated bypass that exceeds applicable pretreatment standards within 24 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; 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 POTW Director may waive the written report on a case-by-case basis if the oral report has been received within 24 hours.
(3) Requirements to establish defense of bypass.
(a) Bypass is prohibited, and the POTW Director may take an enforcement action against 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 waste 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 division (C)(3)(a)2. above.
(b) The POTW Director may approve an anticipated bypass, after considering its adverse effects, if the POTW Director determines that it will meet the three conditions listed in division (C)(3)(a) above.
(Ord. passed 10-14-2021)