A user shall have an affirmative defense to an enforcement action brought against it for noncompliance with the general prohibitions in §
292-26A of this chapter or the specific prohibitions in §
292-26B(3) through
(18) 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 Town of Windsor Locks was regularly in compliance with its NPDES
permit, and in the case of interference, was in compliance with applicable
sludge use or disposal requirements.