(A) Prohibitions. No person shall discharge or cause to be discharged any of the following described waters or wastes to any public sewer.
(1) Any gasoline, benzene, naphtha, fuel oil, lubricating oil or other inflammable or explosive liquid, solid or gas or other substances which, by themselves or by interaction with other substances, may cause fire or explosion hazards, or in any other way be injurious to persons, property, or the operation of the wastewater facilities.
(2) Any waters or waste containing toxic or poisonous solids, liquids, or gases in sufficient quantity, either singly or by interaction with other wastes, which will injure or interfere with any waste treatment process, constitute a hazard to humans or animals, create a public nuisance in the receiving waters of the wastewater treatment plant, or interfere with the disposal of sludge.
(3) Any waters or wastes having a pH lower than 6.0, or having any other corrosive property capable of causing damage or hazard to structures, equipment, and personnel of the wastewater treatment works.
(4) Any waters or wastes having a pH in excess of 9.0.
(5) Solid or viscous substances in quantities or of such size capable of causing obstruction of the flow in sewers, or other interference with the proper operation of the wastewater facilities such as, but not limited to, ashes, cinders, sand, mud, straw, shavings, metal, glass, rags, feather, tar, plastics, wood, unground garbage, whole blood, paunch manure, hair and fleshings, entrails, and paper dishes, cups, milk containers, and the like, either whole or ground by garbage grinders.
(6) Any discharge into the sanitary sewerage system that is in violation of the requirements of the NPDES permit and the modifications thereof.
(B) Limitations as to discharge. No person shall discharge or cause to be discharged the following specifically described substances, materials, fluids, or solids which may harm sanitary sewers, wastewater treatment works and equipment, have an adverse effect on the receiving stream, or may otherwise endanger life, limb, public property, or constitute a nuisance, without the specific written permission of the approving authority. Permission is subject to termination at any time upon written notice. In forming its opinion as to the acceptability of these wastes, the approving authority will give consideration to such factors as the quantities of subject wastes in relation to flows and velocities in the sanitary sewers, materials of construction of sanitary sewers, nature of the wastewater treatment works, capacity of the wastewater facilities and other pertinent factors. The substances prohibited are as follows.
(1) Wastewater having a temperature higher than 150°F.
(2) Wastewater from industrial plants containing floatable oils, fat or grease.
(3) Any garbage that has not been properly shredded. Garbage grinders may be connected to sanitary to sanitary sewers from homes, hotels, institutions, restaurants, hospitals, catering establishments, or similar places where garbage originates from the preparation of food in kitchens for the purpose of consumption on the premises or when served by caterers.
(4) Any waters or waste containing iron, chromium, copper, zinc, mercury, and similar objectionable or toxic substances, to such degree that any such material received in the composite wastewater at the wastewater treatment works exceeds the limits established by the approving authority for such materials, or toxic pollutants in amounts exceeding the standards promulgated by the U.S. Environmental Protection Agency pursuant to Section 307(a) of the Clean Water Act.
(5) Any waters or wastes containing odor-producing substances exceeding limits which may be established by the approving authority.
(6) Any radioactive wastes or isotopes of such half-life or concentration as may exceed limits established by the approving authority in compliance with applicable state or federal regulations.
(7) Quantities of flow, concentrations, or both which constitute a shock as defined is § 51.01.
(8) Incompatible pollutants containing substances which are not amenable to treatment or reduction by the wastewater treatment processes employed, or are amenable to treatment only to such degree that the wastewater treatment plant effluent cannot meet the requirements of other agencies having jurisdiction over discharge to the receiving waters.
(9) Any water or wastes which, by interaction with other water or wastes in the public sewer system, release obnoxious gases from suspended solids which interfere with the collection system, or create a condition deleterious to structures and treatment processes.
(10) Materials which exert or cause the following.
(a) Unusual BOD, chemical oxygen demand or chlorination requirements in such quantities as to constitute a significant load on the wastewater treatment plant.
(b) Unusual volume of flow or concentration of wastes constituting shocks as defined in § 51.01.
(c) Unusual concentrations of inert suspended solids, such as, but no limited to, fuller’s earth, lime slurries, and lime residues, or of dissolved solids, such as but not limited to sodium sulfate.
(d) Excessive discoloration, such as, but not limited to, dye wastes and vegetable tanning solutions.
(C) Groundwater.
(1) The City Council finds that the discharge of water from roof, surface, groundwater sump pump, footing tile or swimming pool or other natural precipitation into the city sewerage system will, and has on numerous occasions in the past, flooded and overloaded the sewerage system to such an extent as to cause significant and grave damage to the waste treatment plant. This damage is caused by the backup of sewage into the plant. The City Council, therefore, finds it essential to the minimization of damage to property and to meet Minnesota Pollution Control Agency and Preston Public Utilities Commission regulations, that the provisions of this division be strictly enforced to avoid emergencies in the future.
(2) No water from any roof, surface, groundwater, sump pump, footing tile, outdoor swimming pool or other natural precipitation shall be discharged into the sanitary sewer system. Dwellings and other buildings and structures which require a sump pump discharge system because of infiltration of water into basements, crawl spaces and the like, shall have a permanently installed discharge line, which shall not at any time discharge water into the sanitary sewer system, except as provided herein. A permanent installation shall be one which provides for year-round discharge capability to either the outside of the dwelling, building or structure, or is connected to the city storm sewer or discharges through the curb and gutter to the street. It shall consist of a rigid discharge line, without valving or quick connections for altering the path of discharge.
(Ord. 170, passed 8-10-1981) (Ord. 232, passed 11-15-1999) Penalty, see § 10.99