A. Protection Of Sewage System: No person shall discharge or cause to be discharged any unpolluted water such as stormwater, surface water, groundwater, roof runoff, subsurface drainage, or cooling water to any sewer.
B. Unpolluted Drainage: Stormwater and all other unpolluted drainage shall be discharged to such sewers as are specifically designated as storm sewers, or to a natural outlet approved by the director of public works and the Montana state department of health. Unpolluted industrial cooling water or process waters may be discharged, upon approval of the director of public works, to a storm sewer or natural outlet.
C. Prohibited Discharges: 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. Pollutants which create a fire or explosion hazard including, but not limited to, waste streams with a closed cup flashpoint of less than one hundred forty degrees Fahrenheit (140°F) or sixty degrees Celsius (60°C) using the test methods specified in 40 CFR 261.21. These wastes include, but are not limited to, gasoline, benzene, naphtha, fuel oil, etc., in solid, liquid or gaseous form.
2. Toxic or poisonous solids, liquids, or gases in sufficient quantity, either singly or by interaction with other wastes, to contaminate the sludge of any municipal system, to injure or interfere with any sewage treatment process or equipment, constitute a hazard to humans or animals, create a public nuisance, or result in the pass through of inadequately treated wastes to receiving waters.
Each user which discharges any toxic pollutants which cause an increase in the cost of managing the effluent or the sludge of the city treatment works shall pay for such increased costs.
3. 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, cinders, sand, mud, straw, shavings, metal, glass, rags, feathers, tar, plastics, wood, unground garbage, whole blood, paunch manure, hair and fleshings, entrails, paper dishes, cups, milk containers, etc., either whole or ground by garbage grinders.
D. Harmful Materials/Substances: The following described substances, materials, waters and wastes shall be limited in discharges to municipal systems to concentrations or quantities which will not harm either the sewers, the sludge of any municipal system, the wastewater treatment process or equipment, will not have an adverse effect on the receiving stream, or will not otherwise endanger lives, limb, public property, or constitute a nuisance. The engineer may set limitations lower than the limitations established in the regulations below if, in his opinion, such more severe limitations are necessary to meet the above objectives. In forming his opinion as to the acceptability, the director of public works will give consideration to such factors as the quantity of subject waste in relation to flows and velocities in the sewers, materials of construction for the sewers, the wastewater treatment process employed, capacity of the wastewater treatment plant, and other pertinent factors. The limitations or restrictions on materials or characteristics of waste or wastewaters discharged to the sanitary sewer which shall not be violated without approval of the engineer are as follows:
1. Wastewater having a temperature higher than one hundred fifty degrees Fahrenheit (150°F) (65°C).
2. Wastewater containing petroleum oil, nonbiodegradable cutting oils, or product of mineral oil origin.
3. Wastewater from industrial plants containing floatable oils, fat, or grease.
4. Any garbage that has not been properly shredded. 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 toxic or deleterious substances to such degree that any such material received in the composite wastewater at the wastewater treatment works exceeds the limits established by the director of public works for such materials.
6. Any waters or wastes containing pollutants which result in the presence of toxic or obnoxious gases, vapors or fumes within the POTW in quantities which may cause acute worker health and safety concerns or public nuisance.
7. Any radioactive wastes or isotopes of such half life or concentration as may exceed limits established by the director of public works in compliance with applicable state or federal regulations.
8. Quantities of flow, concentrations, or both, which constitute a "slug" as defined herein.
9. Waters and wastes 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 the receiving waters.
10. Any water or wastes which, by interaction with other water or wastes in the public sewer system, release obnoxious gases, form suspended solids which interfere with the collection system, or create a condition deleterious to structures and treatment processes.
11. Pollutants which cause corrosive structural damage to the POTW but in no case discharges with pH lower than 5.0 unless the POTW is specifically designed to accommodate such discharges.
12. Any trucked or hauled wastes unless the POTW is designed to adequately treat the wastes and the facility has points designated for such discharges.
E. Interceptors:
1. Required: Grease, oil and sand interceptors shall be provided when, in the opinion of the director of public works, they are necessary 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.
2. Type; Capacity: All interceptors shall be of a type and capacity approved by the director of public works and shall be located as to be readily and easily accessible for cleaning and inspection.
3. Construction: 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.
4. Maintenance: Where installed, all grease, oil and sand interceptors shall be maintained by the owner, at his expense, in continuously efficient operation at all times.
F. Review And Approval Required: The admission into the public sewers of any waters or wastes having: 1) a five (5) day biochemical oxygen demand greater than three hundred (300) parts per million by weight, 2) containing more than three hundred fifty (350) parts per million by weight of suspended solids, 3) containing any quantity of substances having the characteristics described above, or 4) having an average daily flow greater than two percent (2%) of the average daily sewage flow of the city, shall be subject to the review and approval of the engineer.
G. Pretreatment:
1. Required: Where necessary in the opinion of the director of public works, the owner shall provide, at his expense, such preliminary treatment as may be necessary to: a) reduce the biochemical oxygen demand to three hundred (300) parts per million and the suspended solids to three hundred fifty (350) parts per million by weight, b) reduce objectionable characteristics or constituents to within the maximum limits provided for in subsection F of this section, or c) control the quantities and rates of discharge of such waters or wastes.
2. Approval Required: Plans, specifications and any other pertinent information relating to proposed preliminary treatment facilities shall be submitted for the approval of the director of public works and of the board of health of the state of Montana, and no construction of such facilities shall be commenced until said approvals are obtained, in writing.
3. Maintenance: Where preliminary treatment facilities are provided for any waters or wastes, they shall be maintained continuously in satisfactory and effective operation, by the owner at his expense.
H. Surcharge Rate: The city, or its director of public works, will determine the average total suspended solids (TSS) and biochemical oxygen demand (BOD) daily loadings for the average nonindustrial user. The city, or its director of public works, will assess a surcharge rate for all industrial users discharging wastes with BOD and TSS strengths greater than the average nonindustrial user. Such users will be assessed a surcharge sufficient to cover the costs of treating such users' above normal strength wastes. Normal strength wastes are considered to be one hundred fifty five (155) ppm BOD and one hundred fifty seven (157) ppm TSS.
I. Manhole: When required by the director of public works, 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 waste. Such manhole, when required, shall be accessible and safely located and shall be constructed in accordance with the plans approved by the director of public works. 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.
J. Measurement Of Characteristics: All measurements, tests and analysis of the characteristics of water and wastes to which references are made in the above sections shall be determined in accordance with "Standard Methods For The Examination Of Water And Sewage", and shall be determined at the control manhole provided for in subsection 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 Agreement And/Or Agreements: No statement contained in 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. 552, 6-2-2014)