A. Prohibited Uses. It is unlawful to discharge or permit to be discharged any of the following described waters or wastes to any public sewer:
1. Any gasoline, benzene, naphtha, fuel oil, or other flammable or explosive liquid, solid or gas;
2. Any waters or wastes containing toxic or poisonous solids, liquids or gases in sufficient quantity, either singly or by interaction with other wastes, to injure or interfere with any sewer treatment process, constitute a hazard to humans or animals, create a public nuisance, or create any hazard in the receiving waters of the sewage treatment plant;
3. Any waters or wastes having a pH lower than 5.5 or having any other corrosive property capable of causing damage or hazard to structures, equipment and personnel of the sewage works;
4. Solid or viscous substances in quantities or of such size capable of causing obstruction to the flow in sewers, or other interference with the proper operation of the sewage works such as, but not limited to, ashes, cinders, sand, mud, straw, shavings, metal, glass, rags, feathers, tar, plastic, wood, unbound garbage, whole blood, paunch-belly manure, hair and flashings, entrails and paper dishes, cups and milk containers, either whole or ground by garbage grinders.
B. Uses Requiring Approval of Director. It is unlawful to discharge or cause to be discharged the following described substances, materials, waters or wastes if it appears likely in the opinion of the Director of Public Works that such works can harm either the sewers, sewerage treatment process or equipment; have an adverse effect on the receiving stream; or can otherwise endanger life or public property, or constitute a nuisance. In forming an opinion as to the acceptability of these wastes, the Director of Public Works will give consideration to such factors as the quantities of subject wastes in relation to flows and velocities in the sewers, materials or construction of the sewers, nature of the sewage treatment plant, and maximum limits established by regulatory agencies. The substances prohibited are:
1. Any liquid or vapor having a temperature higher than one hundred fifty (150) degrees F (sixty-five (65) C);
2. Any waters or wastes containing toxic or poisonous materials; or oils, whether emulsified or not, in excess of one hundred (100) mg/l or containing substances which may solidify or become viscous at temperatures between thirty-two (32) degrees F and one hundred fifty (150) F (zero (0) degrees C and sixty-five (65) degrees C);
3. Any garbage that has not been properly shredded. The installation and operation of any garbage grinder equipment with a motor of three-quarter horsepower (0.76 hp metric) or greater shall be subject to the review and approval of the Director of Public Works;
4. Any waters or wastes containing strong acid, iron pickling wastes or concentrated plating solution whether neutralized or not;
5. Any waters or wastes containing iron, chromium, copper, zinc, or 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 Director of Public Works for such materials;
6. Any waters or wastes containing phenols or other taste or odor producing substances, in such concentrations exceeding limits which may be established by the Director of Public Works as necessary after treatment of the composite sewage, to meet the requirements of the state, federal, or other public agencies having jurisdiction for such discharge to the receiving waters;
7. Any radioactive wastes or isotopes of such half-life or concentration as may exceed limits established by the Director of Public Works in compliance with applicable state and federal regulations;
8. Any wastes or waters having a pH in excess of 9.5;
9. Any mercury or any of its compounds in excess of 0.0005 mg/l as HG at any time except as permitted by the Director of Public Works in compliance with applicable state and federal regulations;
10. Any cyanide in excess of two mg/liter at any time except as permitted by the Director of Public Works in compliance with applicable state and federal regulations;
11. Materials which exert or cause:
a. Unusual concentrations of inert suspended solids (such as, but not limited to, Fullers earth, lime slurries and lime residues) or of dissolved solids (such as, but not limited to, sodium chloride and sodium sulfate),
b. Excessive discoloration (such as, but not limited to, dye wastes and vegetable tanning solutions),
c. Unusual biochemical oxygen demand, chemical oxygen demand, or chlorine requirements in such quantities as to constitute a significant load on the sewage treatment works,
d. Unusual volume of flow or concentrations of wastes;
12. Waters or wastes containing substances which are not amenable to treatment or reduction by the sewage treatment processes employees, or are amenable to treatment only to such degree that the sewage treatment plant effluent cannot meet the requirements of agencies having jurisdiction over discharge to the receiving waters.
C. Authority of Director. If any waters or wastes are discharged or are proposed to be discharged to the public sewers, which waters contain the substances or possess the characteristics enumerated in subsection B of this section, and/or which are in violation of the standards for pretreatment provided in the applicable federal regulations, and which in the judgment of the Director of Public Works may have a deleterious effect upon the sewage works, processes, equipment or receiving waters, or which otherwise create a hazard to life or constitute a public nuisance, the Director of Public Works may, in his or her discretion, do any of the following:
1. Reject the wastes;
2. Require pretreatment to an acceptable condition for discharge to the public sewers;
3. Require control over the quantities and rates of discharge; and/or
4. Require payment to cover the added costs of handling and treating the wastes not covered by existing taxes or sewer charges.
If the Director of Public Works permits the pretreatment or equalization of waste flows, the design and installation of the plants and equipment shall be subject to the review and approval of the Director of Public Works, and subject to the requirements of all applicable codes, ordinances and laws.
(MC-5-2014, § 4, Amended, 04/17/2014; prior code § 25.15)