No person shall discharge or cause to be discharged the following described substances, materials, waters or wastes if it appears likely in the opinion of the city that such wastes can harm either the sewers, sewage treatment process or equipment, have an adverse effect on the receiving stream, or can otherwise endanger life, limb or public property, or constitute a nuisance. In forming this opinion as to the acceptability of these wastes, the city will give consideration to such factors as to quantities of subject wastes in relation to flows and velocities in the sewers, materials of construction of the sewers, nature of the sewage treatment process, capacity of the sewage treatment plant, degree of treatability of wastes in the sewage treatment plant, and other pertinent factors. The substances prohibited are:
A. Any liquid or vapor having a temperature higher than one hundred fifty degrees Fahrenheit (150°F) (65°C) which will inhibit biological activity in the treatment plant; but in no case wastewater with a temperature at the introduction into the POTW treatment plant which exceeds one hundred four degrees Fahrenheit (104°F) (40°C);
B. Any water or waste containing fats, gas, grease or oils, whether emulsified or not, in excess of one hundred milligrams per liter (100 mg/l) or containing substances that may solidify or become viscous at temperatures between thirty two (32) and one hundred fifty degrees Fahrenheit (150°F) (0 and 65°C);
C. Any garbage that has not been properly shredded. The installation and operation of any garbage grinder equipped with a motor of three-fourths (3/4) horsepower or greater shall be subject to the review and approval of the city;
D. Any waters or wastes containing strong acid iron pickling wastes or concentrated plating solutions, whether neutralized or not;
E. Any waters or wastes containing iron, chromium, copper, zinc and similar objectionable or toxic substances; or wastes exerting an excessive chlorine requirement, to such degree that any such material received in the composite sewage at the sewage treatment works exceeds the limits established by the city for such materials;
F. Any waters or wastes containing phenols or other taste or odor-producing substances, in such concentrations exceeding limits which may be established by the city as necessary, after treatment of the composite sewage, to meet the requirements of the state, federal or other public agencies having jurisdiction of such discharge to the receiving waters;
G. Any radioactive wastes or isotopes of such half-life or concentration as may exceed limits established by the city in compliance with applicable state or federal regulations;
H. Materials that exert or cause:
1. Unusual concentrations of inert suspended solids, such as, but not limited to, fuller’s earth, lime slurries and lime residues or of dissolved solids, such as, but not limited to, sodium chloride and sodium sulfate;
2. Excessive discoloration, such as, but not limited to, dye wastes and vegetable tanning solutions;
3. Unusual BOD, chemical oxygen demand or chlorine requirements in such quantities as to constitute a significant load on the sewage treatment works or to exceed the limitation set forth in national categorical pretreatment standards;
4. Unusual volume of flow or concentration of wastes constituting “slug” as defined herein;
I. Waters or wastes containing substances that are not amenable to treatment or reduction by the sewage treatment processes employed, or are amenable to treatment only to such degree that the sewage treatment plant effluent cannot meet the requirements or other agencies having jurisdiction over discharge to the receiving waters.
J. Any substance which may cause the POTW’s effluent or treatment residues, sludges or scums to be unsuitable for reclamation and reuse or to interfere with the reclamation process.
K. Any unpolluted water above two thousand (2,000) gallons per day, including, but not limited to, noncontact cooling water. (Ord. 1526 § 1, 2023: Ord. 993 § 3, 1989: Ord. 895, 1978)