An industrial user shall have an affirmative defense to an enforcement action brought against it for noncompliance with the general and specific prohibitions in §
435-5 of this chapter 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 prior discharge when the City of Las Vegas was
regularly in compliance with its NPDES permit, and in the case of
interference, was in compliance with applicable sludge use or disposal
requirements.