(A) Prohibited use. No person shall discharge or cause to be discharged any storm water, surface water, ground water, roof runoff, subsurface drainage, cooling water or unpolluted industrial process waters to any sanitary sewer.
(B) Storm waters and unpolluted drainage. Storm water and all other unpolluted drainage shall be discharged to such sewers as are specifically designed as storm sewers, or to a natural outlet approved by the City Engineer. Industrial cooling water or unpolluted process waters may be discharged, upon approval of the City Engineer, to a storm sewer, or natural outlet.
(C) Prohibited substances. Except as hereinafter provided, no person shall discharge or cause to be discharged any of the following described waters or wastes to any public sewer:
(1) Any liquid or vapor having a temperature higher than 150° F.
(2) Any water or waste which may contain more than 100 parts per million by weight of fat, oil or grease.
(3) Any gasoline, benzine, 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, paunch manure, or any other solid or viscous substance capable of causing obstruction to the flow in sewers or other interference with the proper operation of the sewage works.
(6) Any waters or wastes having a pH lower than 5.5 or higher than 9.0 or having any other corrosive property capable of causing damage or hazard to structures, equipment, and personnel of the sewage works.
(7) Any waters or wastes containing a toxic or poisonous substance in sufficient quantity to injure or interfere with any sewage treatment process, which constitute a hazard to humans or animals, or create any hazard in the receiving waters of the sewage treatment plant.
(8) Any waters or wastes containing suspended solids of such character and quantity that unusual attention or expense is required to handle such materials at the sewage treatment plant.
(9) Any noxious or malodorous gas or substance capable of creating a public nuisance.
(D) Requirement of interceptors. Grease, oil, and sand interceptors shall be provided, as determined by the City Engineer, for the proper handling of liquid wastes containing grease in excessive amounts or any flammable wastes, sand, and other harmful ingredients; except that such interceptors shall not be required for private living quarters or dwelling units. All such interceptors shall be of a type and capacity approved by the City Engineer, and shall be located as to be readily and easily accessible for cleaning and inspection. Grease and oil interceptors shall be constructed of impervious materials capable of withstanding abrupt and extreme changes in temperature. They shall be of substantial construction, watertight, and equipped with easily removable covers which when bolted in place shall be gastight and watertight. Where installed, all grease, oil and sand interceptors shall be maintained by the owner, at his expense, in continuously efficient operation at all times, and shall be subject to inspection by the city or other governmental public health agents.
(E) Certain types of uses; subject to approval. The admission into the public sewers of any water or wastes having a five-day biochemical oxygen demand greater than 300 parts per million by weight; or containing more than 350 parts per million by weight of suspended solids; or containing any quantity of substances having characteristics described in division (C) or (D) of this section having an average daily flow greater than 2% of the average daily sewage flow of the city is subject to the review and approval of the City Engineer.
(F) Preliminary treatment. The owner shall provide at his expense, such preliminary treatment as may be necessary to reduce the biochemical oxygen demand to 300 parts per million and the suspended solids to 350 parts per million by weight; or reduce objectionable characteristics of constituents to within the maximum limits provided for in division (C) of this section, or control the quantities and rates of discharge of such water or wastes. Plans, specifications, and any other pertinent information relating to proposed preliminary treatment facilities shall be submitted for the approval of the City Engineer and of the Minnesota Pollution Control Agency, and no construction of such facilities shall be commenced until said approvals are obtained in writing.
(G) Maintenance of preliminary treatment facilities. Where preliminary treatment facilities are provided for any waters or wastes, they shall be maintained continuously in satisfactory and effective operation, and records maintained concerning quality of the effluent, by the owner, at his expense. Such facilities and all associated records shall be subject to inspection by the city.
(H) Maintenance of services. The property owner shall be responsible for maintenance of the building service, including cleaning, repair and replacement. All other city requirements shall be met in the maintenance of building services.
(I) Requirements of manholes. The owner of any property served by a building sewer carrying industrial wastes shall install a suitable control manhole in the building sewer to facilitate observation, sampling and measurement of the wastes. Such manhole, shall be accessible and safely located, and shall be constructed in accordance with plans approved by the City Engineer. The manhole shall be installed by the owner, at his expense, and shall be maintained by him so as to be safe and accessible at all times. The city shall have right of access to inspect or sample effluent at all times.
(J) Measurements tests and analyses. All measurements, tests and analyses of the characteristics of waters and wastes to which reference is made in division (C) and (E) of this section shall be determined in accordance with methods employed by the Minnesota Department of Health, and shall be determined at the control manhole provided for in division (I) of this section, or upon suitable samples taken at said control manhole. In the event that no special manhole has been required, the control manhole shall be considered to be the nearest downstream manhole in the public sewer to the point at which the building sewer is connected.
(K) Special provisions; industrial wastes. No provision of this section shall be construed as preventing any special agreement or arrangement between the city and any industrial concern whereby an industrial waste of unusual strength or character may be accepted by the city for treatment subject to payment therefor by the industrial concern.
(Ord. 1227, passed 8-26-91) Penalty, see § 4.408