An industrial user shall have an affirmative defense to an enforcement action brought against it for noncompliance with the general and specific prohibitions in § 51.020 if it can prove that it did 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 use or disposal requirements.
(1960 Code, § 38-14-91) (Ord. 5677, passed 12-16-1996; Am. Ord. 8173-2018, passed 2-21-2018)