§ 50.31 DISCHARGE OF SURFACE WATER.
   (A)   Discharge of surface water. No person shall discharge or cause to be discharged any storm sewer, surface water, groundwater, cooling water or unpolluted industrial process waters into any sanitary sewer. No rain spout or other form of surface drainage and no foundation drainage shall be connected with any sanitary sewer.
   (B)   Non-acceptable wastes. No person shall discharge or permit to be discharged into any public sewer any of the following wastes:
      (1)   Any liquid or vapor having a temperature in excess of 180° F.;
      (2)   Any water or waste having a five-day biological oxygen demand exceeding 1,000 parts per million by weight as averaged during any 12-month period;
      (3)   Any gasoline, benzene, naphtha, fuel, oil or other flammable or explosive liquid, solid or gas;
      (4)   Any garbage that has not been properly shredded;
      (5)   Any ashes, cinders, sand, mud, straw, shavings, metal, glass, rags, feathers, tar, plastics, wood, manure, grit, brick, cement, onyx, carbide or other matter that may interfere with the proper operation of the sewers or sewage works;
      (6)   Any water or waste having a pH lower than six or higher than nine or having any other corrosive property capable of causing damage or hazard to structures, equipment, or personnel of the sewage works;
      (7)   Any water or waste containing a toxic or poisonous substance, whether or not listed as a hazardous waste by Minnesota Rules part 7045.0135, as it may be amended from time to time, in sufficient quantities to constitute a hazard to humans or animals, injure or interfere with sewage treatment, or create any hazard in the receiving waters of the sewage treatment plant; or
      (8)   Any noxious or malodorous gas or substance capable of creating a public nuisance.
   (C)   Interceptors. Grease, oil and sand interceptors shall be provided when they are necessary for the proper handling of any liquid waste containing grease in excessive amounts or any flammable waste, sand or other harmful ingredients; but such interceptors shall not be required for private living quarters or dwelling units. Interceptors shall be located so as to be easily accessible for cleaning and inspection.
   (D)   Control manhole required. The owner of any property served by a building sewer carrying industrial waste shall install a suitable control manhole in the building sewer to facilitate observation and sampling of the waste. The manhole shall be constructed by the owner in accordance with plans approved by the City Engineer. The owner shall maintain the manhole so as to be safe and accessible at all times.
   (E)   Separate sewers. A separate and independent sewer shall be provided for every building connected to the sewer system, except that the Council may waive this requirement where it finds that a separate sewer for a building is impractical.
   (F)   Inspections.
 
      (1)   The city’s Utilities Superintendent and other authorized employees of the city, bearing proper credentials and identification, shall, at reasonable times, be permitted to enter upon all properties connected to the city sanitary sewer system for the purpose of inspection, observation, measurement, sampling and testing.
      (2)   The premises of any property owner or occupant, who refuses entry to a city employee, after a proper request as provided for in this section, shall be terminated from the connection with the city sanitary system. The termination of connection shall be effected by the city only after a hearing before the City Council upon ten days mailed notice to the owner or occupant concerned.
      (3)   The requirements of § 50.32, for connection to the city sanitary sewer system, shall not be applicable to property disconnected under this section. However, any property producing sewage shall be equipped with an adequately maintained and liquid tight holding tank.
(’77 Code, § 403.02) Penalty, see § 10.99