(A)   No person shall discharge or cause to be discharged any substances, materials, waters or wastes if it appears likely in the opinion of the City Engineer that the 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, public property or constitute a nuisance.
   (B)   In forming his or her opinion as to the acceptability of these wastes, the City Engineer will give consideration to the factors as the quantities of subject wastes in relation to flow and velocities in the sewers, materials of construction of the sewers, nature of the sewage treatment process, capacity 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.
   (C)   The prohibited substances are:
      (1)   Any liquid or vapor having a temperature higher than 150°F. or 65°C.;
      (2)   Any water or waste containing fats, wax, grease or oils, whether emulsified or not, in excess of 100 mg/l or containing substances which may solidify or become viscous at temperatures between 32°F. and 150°F. or 0°C. and 65°C.;
      (3)   Any garbage that has not been properly shredded;  (The installation and operation of any garbage grinder equipped with a motor of three-fourths horsepower or greater shall be subject to the review and approval of the City Engineer.)
      (4)   Any waters or wastes containing strong acid iron pickling wastes or concentrated plating solutions whether neutralized or not;
      (5)   Any waters or wastes containing iron, chromium copper, zinc and similar objectionable or toxic substances or wastes exerting an excessive chlorine requirements, to the degree that any material received in the composite sewage at the sewage treatment works exceeds the limits established by the City Engineer for the materials;
      (6)   Any waters or wastes containing phenols or other taste or odor producing substances, in concentrations exceeding limits which may be established by the City Engineer as necessary, after treatment of composite sewage, to meet the requirements of the state, federal or other public agencies of jurisdiction for discharge to the receiving waters;
      (7)   Any radioactive wastes or isotopes of the half-life or concentration as may exceed limits established by the City Engineer in compliance with applicable state and federal regulations;
      (8)   Materials which exert of cause are as follows:
         (a)   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);
         (b)   Excessive discoloration (such as, but not limited to dye wastes and vegetable tanning solutions);
         (c)   Unusual BOD, chemical oxygen demand or chlorine requirements (such as, but not limited to whey, whole or separated milk, yeast, whole blood and the like) in quantities as to constitute a significant load on the sewage treatment works; and/or
         (d)   Unusual volume of flow or concentration of wastes constituting “slugs,” as defined herein.
      (9)   Waters or wastes containing substances which are not amenable to treatment or reduction by the sewage treatment processes employed, or are amenable to treatment only to the degree that the sewage treatment plant effluent cannot meet the requirements of other agencies having jurisdiction over discharge to the receiving waters.
(`90 Code, § 18-9)  (Ord. 2520, passed - -)