A user shall have an affirmative defense to an enforcement action brought against it for noncompliance with the general prohibitions in §
67-27A of this chapter or the specific prohibitions in §
67-27B(3) through
(16) 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:
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 the Greater Greensburg Sewage Authority was regularly in compliance
with its NPDES permit and, in the case of interference, was in compliance
with applicable sludge use or disposal requirements.