8.1 mg/L zinc

• 1.8 mg/L selenium

100 mg/L total oil or grease.

All concentrations for metallic substances are for total metal, unless indicated otherwise. The City may impose mass limitation in addition to the concentration-based limitations above.

• B. Dilution prohibited. No user shall ever increase the use of process waste, or in any way attempt to dilute a discharge, as a partial or complete substitute for adequate treatment to achieve compliance with a discharge limitation, unless expressly authorized by an applicable pretreatment standard or requirement. The City may impose mass limitations on users who are using dilution to meet applicable pretreatment standards or requirements, or in cases when the imposition of mass limitation is appropriate.

• C. National categorical pretreatment standards. Users must comply with the categorical pretreatment standards found in 40 CFR Chapter I, Subchapter N, Parts 405-471.

• D. BMPs. The Public Works Director may establish BMPs, to implement this section and the requirements of Chapter 16.04. The BMPs may be established by administrative guidelines or as conditions of issuance of a Waste Discharge Permit.

(Ord. 3883, 1977; Ord. 4589, 1989; Ord. 4775, 1992; Ord. 5078, 1998; Ord. 5675, 2014; Ord. 5977, 2020; Ord. 6124, 2023)