(1) Surface Waters. Any stormwater, surface water, groundwater, roof runoff, subsurface drainage, cooling water or unpolluted industrial process waters.

(2) High Temperature. Any liquid or vapor having a temperature higher than 150 degrees Fahrenheit.

(3) Fat, Oil, Grease. Any water or waste which contains more than 100 parts per million, by weight, of fat, oil or grease.

(4) Flammable Materials. Any gasoline, benzene, naphtha, fuel oil or other flammable or explosive liquid, solid or gas.

(5) Garbage. Any garbage that has not been properly shredded.

(6) Solid or Viscous Substance. Any ashes, cinders, sand, mud, straw, shavings, metal, glass, rags, feathers, tar, plastics, wood, paunch manure, or any other solid or viscous substance capable of causing the obstruction of the flow in sewers or other interference with the proper operation of the city sewage system.

(7) Noxious or Malodorous Gas. Any noxious or malodorous gas or other substance which either singly or by interaction with other wastes is capable of creating a public nuisance or hazard to life or of preventing entry into sewers for their maintenance and repair.

(8) Toxic or Poisonous Substance. Any water or waste containing a toxic or poisonous substance in sufficient quantity to injure or interfere with the sewage system, that would constitute a hazard to humans or animals, or create any hazard in the receiving waters of the sewage system.

(9) Suspended Solids. Any waters or waste containing suspended solids of such character and quantity that unusual attention or expense is required to handle such material at the sewage treatment plant.

(10) Corrosive Wastes. Any water or wastes having corrosive properties capable of causing damage or hazard to structures, equipment or personnel of the sewage system. Free acids and alkalis of such wastes must be neutralized within a permissible range of pH between 4.5 and 10.0.

(11) Slugs. Any wastes that for a duration of 15 minutes have a concentration greater than five times that of “normal sewage” as measured by suspended solids and BOD.

(12) Materials Which React with Water or Wastes. Any waters, wastes, materials or substances which react with water or wastes in the sewer system to release noxious gases, develop color of undesirable intensity, form suspended solids in objectionable concentration or create any other condition deleterious to structures and treatment processes.

(13) Special Agreements Permitted. No statement in this section shall be construed as preventing any special agreement, arrangement or contract between the council, and any industrial concern whereby an industrial waste of unusual strength or character may be accepted subject to special conditions, rate and cost as established by the council.

(14) Surface Waters Exception. Special permits for discharging surface waters to a public sanitary sewer may be issued by the council upon recommendation of the city manager where such discharge is deemed necessary or advisable for purposes of flushing, but any permit so issued shall be subject to revocation at any time when deemed to the best interests of the sewer system. [Code 1975 § 3-3.0111.]