A.   All Sewers: Sewage, waste or any matter having any of the following characteristics shall, under no conditions, be discharged into, be placed where they might find their way into, or be allowed to run, leak, or escape into any part of the sewer system including:
      1.   Ashes, cinders, sand, earth, coal, rubbish or any matter which is chemically or physically stable for at least five (5) days at twenty degrees Centigrade (20°C) or which would form a deposit or obstruction or damage or reduce the capacity of sewer into which it was placed.
      2.   Liquids, gases, or solids or any matter which after entrance into a sewer might reasonably be expected to form into flammable, explosive or poisonous liquids, gases or solids.
      3.   Liquid matter of any nature containing suspended solids in excess of one thousand (1,000) parts per million.
      4.   Matter of any nature containing five (5) day biochemical oxygen demand in excess of three hundred (300) parts per million or any petroleum products.
      5.   Animal or vegetable greases, oils or matter containing animal or vegetable greases or oil of any nature in excess of three hundred (300) parts per million. Grease trap and further methods of pretreatment necessary to reduce the grease loading to acceptable levels shall be employed by the user before the liquid enters the sewerage fixtures.
      6.   Liquid matter with a hydrogen ion (pH) concentration, below 5.5 or above 9.0 measured at the point where discharge enters the sewer main.
      7.   Any matter that would be poisonous to or inhibit the organisms associated with any sewage treatment process, and which in the opinion of the department, might interfere with the satisfactory operation of any treatment facility or any portion of the sewer system.
Upon obtaining the written approval of the director, sewage wastes or other matters herein excluded may be discharged into the sewage system upon the payment to city of the additional costs for processing the same as hereinafter provided and set forth.
   B.   Storm Drains: In addition to the matter excluded in subsection A of this section, all other matter of any nature shall be excluded from pipes and ditches designated by the director as storm drains, excepting only surface drainage waters. All drainage waters shall be directed into storm drains only under the authorization and direction of the director.
   C.   Sanitary Sewers: In addition to the matter excluded heretofore, all surface drainage water (inflow) shall be excluded from all parts of the city sewer system. (Ord. 453, 11-29-1990)