No statement contained in this article shall be construed as preventing any special agreement or arrangement between the city and any industrial discharger whereby an industrial waste of unusual strength or character may be proposed by the city for treatment, subject to payment therefore by the industrial discharger and subject to such terms and conditions as might be required by the city. However, no special agreement shall be allowed to contravene federal, state or local pretreatment standards. (Ord. 2006-02 (part), 2006: Prior code § 4263)