Nothwithstanding the exemptions provided for in Section 15.80.070 above, if the regional board or the director determines that a discharge which is otherwise exempt from the prohibition on discharges causes or significantly contributes to the violation of any receiving water limitation or results in the conveyance of significant quantities of pollutants to surface waters, or is otherwise a danger to public health or safety, the director may give written notice to the owner or operator of the facility that the discharge exception shall not apply to the discharge at issue following expiration of the thirty day period commencing upon delivery of the notice. Upon expiration of such thirty day period, any such discharge shall be unlawful. (Ord. 2209 NCS §1 (part), 2005.)