A user shall have an affirmative defense to an enforcement action brought against it for noncompliance with the general prohibitions in §
52-35A of this Part
3 or the specific prohibitions in §
52-35B of this Part
3 if it can prove that it did not know, or have reason to know, that its discharge, alone or in conjunction with discharge from other sources, would cause pass-through or interference and that either:
A. 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
B. No local limit exists, but the discharge did not change
substantially in nature or constituents from the user's prior discharge,
when Lake City Borough was regularly in compliance with its NPDES
permit, and in the case of interference, was in compliance with applicable
sludge use or disposal requirements.