A. Storm And Surface Water Runoff:
1. No person(s) shall discharge or cause to be discharged any unpolluted waters such as storm water, ground water, roof runoff, subsurface drainage, or cooling water to any sanitary sewer in accordance with chapter 6 of this title.
2. 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 and other regulatory agencies. Unpolluted industrial cooling water or process waters may be discharged to a storm sewer or natural outlet on approval of the city and upon approval and issuance of a discharge permit by the MPCA.
B. Prohibited Discharges: No person(s) shall discharge or cause to be discharged any of the following described waters or wastes to any public sewers:
1. Any gasoline, benzene, naphtha, fuel oil, or other flammable or explosive liquid, solid, or gas which, by reason of their nature or quantity, are or may be, sufficient, either alone or by interaction with other substances, to cause fire or explosion, or be injurious in any other way to the treatment facilities or to the operation of the system.
2. Any water containing toxic or poisonous solids, liquids, or gases in sufficient quantity, either singly or by interaction with other wastes, to injure or interfere with any waste treatment process, constitutes a hazard to humans or animals, creates a public nuisance, or creates any hazard in the receiving wastes of the wastewater treatment works. A toxic pollutant shall include, but not be limited to, any pollutant identified pursuant to section 307(a) of the clean water act and revisions thereof.
3. Any waters or wastes having a pH lower than 5.5 or greater than 9.5, or having any other corrosive property capable of causing damage or hazard to structures, equipment and personnel of the wastewater facilities and/or wastewater treatment works.
4. Solid or viscous substances in quantities or of such size capable of causing obstruction to the flow in sewers, or other interference with the proper operation of the wastewater facilities such as, but not limited to, ashes, bones, cinders, sand, mud, straw, shavings, metal, glass, rags, feathers, tar, plastics, wood, whole blood, paunch manure, hair and fleshings, entrails, and paper dishes, cups, milk containers, etc., and either whole or improperly ground garbage.
C. Restricted Discharges: The following described substances, materials, waters, or wastes shall be limited in discharges to municipal systems to concentrations or quantities which will not harm either sewers, wastewater treatment works, treatment process or equipment, will not have an adverse effect on the receiving stream, and/or soil, vegetation and ground water, or will not otherwise endanger lives, limbs, or public property, or constitute a nuisance. The superintendent may set limitations lower than limitations established in this subsection if, in his opinion, such more severe limitations are necessary to meet the above objectives. In forming his opinion as to the acceptability, the superintendent will give consideration to such factors as the quantity of subject waste in relation to flows and velocities in the sewers, materials of construction of the sewers, the wastewater treatment works, the city NPDES and/or SDS permits and other pertinent factors. The limitations or restrictions on materials or characteristics of water or wastewater discharged to the sanitary sewer which shall not be violated without approval of the superintendent are as follows:
1. Wastewater having a temperature higher than one hundred fifty degrees Fahrenheit (150°F) (65 degrees Celsius).
2. Wastewater containing more than twenty five milligrams per liter (25 mg/l) of petroleum oil, nonbiodegradable cutting oils, or product of mineral oil origin.
3. Any wastewater containing fats, wax, grease, or oils, whether emulsified or not, in excess of one hundred milligrams per liter (100 mg/l) or containing substances which may solidify or become viscous at temperatures between thirty two degrees Fahrenheit (32°F) and one hundred fifty degrees Fahrenheit (150°F) (0 degrees Celsius and 65.6 degrees Celsius).
4. Any garbage that has not been properly shredded (see section 9-3-1 of this chapter, definition of "properly shredded garbage"). Garbage grinders may be connected 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.
5. Any waters or wastes containing lead, chromium, copper, zinc, mercury, boron, 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 superintendent for such materials.
6. Any waters or wastes containing odor producing substances, inert suspended solids, wastes with objectionable colors or noxious waters exceeding limits which may be established by the superintendent.
7. Any radioactive wastes or isotopes of such half life or concentration as may exceed limits established by the superintendent in compliance with applicable state or federal regulations.
8. Quantities of flow, concentrations, or both, which constitute a "slug" as defined in section 9-3-1 of this chapter.
9. Waters or wastes containing substances which are not amenable to treatment or reduction by the wastewater treatment processes employed.
10. Any waters or wastes containing BOD or suspended solids of such character and quantity that unusual attention or expense is required to handle such materials at the wastewater treatment works, except as may be permitted by contract between the city and any user which will provide for special charges, payment or provisions of treating and testing equipment in accordance with this chapter.
D. Actions By Superintendent: If any waters or wastes are discharged or are proposed to be discharged to the public sewers, which waters contain the substances or possess the characteristics enumerated in subsections B and C of this section, and which, in the judgment of the superintendent, may have a deleterious effect upon the wastewater facilities, processes, equipment, or receiving waters, or which otherwise create a hazard to life or constitute a public nuisance, the city may:
1. Reject the wastes.
2. Require pretreatment to an acceptable condition for discharge to the public sewers.
3. Require control over the quantities and rates of discharge. (Ord. 2004-11)