§ 90-230. Discharges to public sewers.

(a)

No person shall discharge, or cause to be discharged, any stormwater, surface water, groundwater, roof runoff, subsurface drainage or cooling water to any sanitary sewer. Industrial process waters may be discharged to sanitary sewers, upon approval of the director.

(b)

Stormwater and all other unpolluted drainage shall be discharged to sewers specifically designated as combined sewers or storm sewers, or to a natural outlet approved by the director. Cooling water may be discharged, upon approval of the director, to a storm sewer, combined sewer or natural outlet.

(c)

No person 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.

(2)

Any waters or wastes 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 sewage treatment process, constitute a hazard to humans or animals, create a public nuisance or create any hazard in the receiving waters of the sewage treatment plant, including, but not limited to, cyanides in excess of two mg/l as CN in the wastes as discharged to the public sewer.

(3)

Any waters or wastes having a pH lower than 5.5 or having any other corrosive property capable of causing damage or hazard to structures, equipment or personnel of the sewage 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 sewage works, 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 and paper dishes, cups, milk containers, etc., either whole or ground by garbage grinders.

(d)

No person shall discharge, or cause to be discharged, the following described substances, materials, waters or wastes if it appears likely, in the opinion of the director, that such wastes can harm either the sewers, sewage treatment process or equipment; have an adverse effect on the receiving stream; otherwise endanger life, limb or public property; or constitute a nuisance. In forming such opinion as to the acceptability of such wastes, the director will give consideration to such factors as the quantities of subject wastes in relation to flows and velocities in the sewers; materials of construction of the sewers; nature of the sewage treatment process, capacity of the sewage treatment plant; degree of treatability of wastes in the sewage treatment plant; and other pertinent factors. Substances prohibited include:

(1)

Any liquid or vapor having a temperature higher than 150 degrees Fahrenheit (65 degrees Celsius) or which causes the treatment works influent to exceed 104 degrees Fahrenheit (40 degrees Celsius).

(2)

Any waters or wastes containing fats, wax, grease or oils, whether emulsified or not, in excess of 100 mg/l or containing substances which may solidify or become viscous at temperatures between 32 degrees and 150 degrees Fahrenheit (0 degrees and 65 degrees Celsius).

(3)

Any garbage that has not been properly shredded. The installation and operation of any garbage grinder equipment shall be subject to the review and approval of the director.

(4)

Any waters or wastes containing strong acid iron pickling wastes or concentrated plating solutions, whether or not neutralized.

(5)

Any waters or wastes containing iron, chromium, copper, zinc and similar objectionable or toxic substances, or wastes exerting an excessive chlorine requirement to such a degree that any such material received in the composite sewage at the sewage treatment works exceeds the limits established by the director as necessary after treatment of the composite sewage to meet the requirements of the state, federal or other public agencies of jurisdiction for such discharge to the receiving waters.

(6)

Any radioactive wastes or isotopes of such half-life or concentration as may exceed limits established by the director in compliance with applicable state or federal regulations.

(7)

Any waters or wastes having a pH in excess of nine.

(8)

Materials which exert or cause:

a.

Unusual concentrations of inert suspended solids, such as, but not limited to, Fuller's earth, lime slurries and lime residues, or of dissolved solids, such as, but not limited to, sodium chloride and sodium sulfate.

b.

Excessive discoloration, such as, but not limited to, dye wastes and vegetable tanning solutions.

c.

Unusual BOD, chemical oxygen demand or chlorine requirements in such quantities as to constitute a significant load on the sewage treatment works.

d.

Unusual volume of flow or concentration of wastes constituting slugs.

(9)

Waters or wastes containing substances which are not amenable to treatment or reduction by the sewage treatment processes employed or are amenable to treatment only to such degree that the sewage treatment plant effluent cannot meet the requirements of other agencies having jurisdiction over discharges to the receiving waters.

(e)

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 subsection (d) of this section, and which, in the judgment of the director, may have a deleterious effect upon the sewage works, processes, equipment or receiving waters, or which otherwise create a hazard to life or constitute a public nuisance, the director 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; and/or

(4)

Require payment to cover the added cost of handling and treating the wastes not covered by existing taxes or sewer charges under the provisions of subsection (j) of this section.

If the director permits the pretreatment or equalization of waste flows, the design and installation of the plants and equipment shall be subject to the review and approval of the director and subject to the requirements of all applicable codes, ordinances and laws. The admission into the public sewers of any waters or wastes having a five-day biochemical oxygen demand greater than 300 mg/l, or containing more than 350 mg/l of suspended solids, or having an average daily flow greater than two percent of the average daily sewage flow of the city shall be subject to the review and approval of the director.

(f)

Grease, oil and sand interceptors shall be provided when, in the opinion of the director, they are necessary for proper handling of liquid wastes containing grease in excessive amounts or flammable wastes, sand or other harmful ingredients, except that such interceptors shall not be required for private living quarters or dwelling units. All interceptors shall be of a type and capacity approved by the director and shall be located so as to be readily and easily accessible for cleaning and inspection.

(g)

Where preliminary treatment or flow equalizing facilities are provided for any waters or wastes, they shall be continuously maintained in satisfactory and effective operation by the owner, at such owner's expense.

(h)

When required by the director, the owner of any property serviced by a building sewer carrying industrial wastes shall install a suitable control manhole, together with such necessary meters and other appurtenances in the building sewer as will facilitate observation, sampling and measurement of the wastes. Such manhole, when required, shall be accessibly and safely located and shall be constructed in accordance with plans approved by the director. The manhole shall be installed by the owner, at such owner's expense, and shall be maintained by such owner so as to be safe and accessible at all times.

(i)

All measurements, tests and analyses of the characteristics of waters and wastes to which reference is made in this article shall be determined in accordance with the latest edition of Standard Methods for the Examination of Water and Wastewater, published by the American Public Health Association, and shall be determined at the control manhole provided or upon suitable samples taken at the control manhole. If 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. Sampling shall be carried out by customarily accepted methods to reflect the effect of constituents upon the sewage works and to determine the existence of hazards to life, limb and property. The particular analyses involved will determine whether a 24-hour composite of all outfalls of a premises is appropriate or whether a grab sample should be taken. Normally, but not always, BOD and suspended solids analyses are obtained from 24-hour composites of all outfalls, whereas pHs are determined from periodic grab samples.

(j)

No statement contained in this section shall be construed as preventing any special agreement or arrangement between the commission and any industrial concern whereby an industrial waste of unusual strength or character may be accepted by the commission for treatment, subject to payment by the industrial concern for such treatment.

(Code 1982, § 13-60)