A. No person shall discharge or cause to be discharged any stormwater, surface water, groundwater, roof runoff, subsurface drainage, uncontaminated cooling water, or unpolluted industrial process waters to any sanitary sewer.

B. Stormwater and all other unpolluted drainage shall be discharged to sewers specifically designed as storm sewers by the director of public utilities to another storm sewer or natural outlet. Such flows are also subject to federal and state regulations.

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 waste to: (a) injure or interfere with any wastewater treatment process, or (b) constitute a hazard to humans or animals, or (c) create a public nuisance, or (d) create any hazard in the receiving waters of the wastewater treatment plant;

3. Any waters or wastes having a pH lower than 6.0 or higher than 9.0 or having any other property capable of causing damage or hazard to structures, equipment, and personnel of the treatment works;

4. Solid or viscous substances in quantities or of such size capable of causing obstructions to the flow in sewers, or other interference with the proper operation of the treatment 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 of public utilities that such wastes can harm either the sewers, wastewater treatment process, or equipment, have an adverse effect on the receiving stream, or can otherwise endanger life, limb, public property, or constitute a nuisance. In forming his or her opinion as to the acceptability of these wastes, the director of public utilities 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 wastewater treatment process, capacity of the wastewater treatment plant, degree of treatability of wastes in the wastewater treatment plant, and other pertinent factors. The substances prohibited are:

1. Any liquid or vapor having a temperature higher than one hundred twenty (120) degrees Fahrenheit (forty-nine (49) degrees Celsius);

2. Any water or waste containing fats, wax, grease or oils, whether emulsified or not, in excess of one hundred (100) milligrams per liter or containing substances which may solidify or become viscous at temperatures between thirty-two (32) degrees and one hundred twenty (120) degrees Fahrenheit (zero degrees and forty-nine (49) degrees Celsius);

3. Any garbage that has not been properly shredded. The installation and operation of any garbage grinder equipped with a motor of three-fourths horsepower (0.76 hp metric) or greater shall be subject to the review and approval of the director of public utilities;

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

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 degree that any such material received in the composite wastewater at the waste-water treatment works exceeds the limits established by the director of public utilities for such materials, or pretreatment requirements established by state, federal, or other public agencies or jurisdiction for such discharge;

6. Any waters or wastes containing phenols or other taste- or odor-producing substances, in such concentrations exceeding limits which may be established by the director of public utilities as necessary, after treatment of the composite wastewater to meet the requirements of the state, federal or other public agencies or jurisdiction for such discharge;

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

8. Materials which exert or cause:

a. Unusual concentrations of inert suspended solids (such as, but not limited to, Fullers earth, lime slurries and lime residues) or 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 wastewater treatment works,

d. Unusual volume of flow or concentration of wastes constituting "slugs" as defined in Section 13.16.010 of this chapter;

9. Waters or 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 discharge to the receiving waters;

10. Any waters or wastes (a) having a five-day BOD greater than three hundred (300) milligrams per liter, or (b) containing more than three hundred fifty (350) milligrams per liter of suspended solids, or (c) having an average daily flow greater than two percent of the average wastewater flow of the city, shall be subject to the review of the director of public utilities. Where necessary, in the opinion of the director of public utilities, the owner shall provide, at his or her expense, such preliminary treatment as may be necessary to (a) reduce the BOD to three hundred (300) milligrams per liter, or (b) reduce the suspended solids to three hundred fifty (350) milligrams per liter, (c) control the quantities and rates of discharge of such waters or wastes. Plans, specifications and any other pertinent information relating to proposed preliminary treatment facilities shall be submitted for the approval of the director of public utilities and no construction of such facilities shall be commenced until the approvals are obtained in writing.

E. If any waters or wastes are, or are proposed to be, discharged to the public wastewater collection system which contain the substances or possess the characteristics enumerated in subsection (D) of this section, the director of public utilities may:

1. Reject the wastes;

2. Require pretreatment to an acceptable condition for discharge to the public wastewater collection system;

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 user charges.

If the director of public utilities 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 of public utilities and subject to the requirements of all applicable codes, ordinances and laws.

F. Grease, oil and sand interceptors shall be provided when, in the opinion of the director of public utilities, they are necessary for the proper handling of liquid wastes containing grease in excessive amounts, or any 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 of public utilities and shall be located as to be readily and easily accessible for cleaning and inspection. No materials shall be disposed of directly into manholes. Manhole covers shall be removed only by licensed plumbers or the city utility department.

G. Where preliminary treatment or flow-equalizing facilities are provided for any water wastes, they shall be maintained continuously in satisfactory and effective operation by the owner, at his or her expense.

H. When required by the director of public utilities the owner of any property served 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, to 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 of public utilities. The manhole shall be installed by the owner at his or her expense, and shall be maintained by him or her 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 chapter shall be performed by a laboratory approved by the director of public utilities and 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. 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. Sampling shall be carried out by customarily accepted methods to reflect the effect of the constituents upon the treatment works and to determine the existence of hazards to life, limb and property. (The particular analyses involved will determine whether a twenty-four-hour composite of all building sewers of a premises is appropriate or whether a grab sample or samples should be taken. Normally, but not always, BOD and suspended solids analyses are obtained from twenty-four-hour composites of all building sewers, whereas pHs and heavy metals are determined from periodic grab samples.)

J. Any pretreatment standards, as established by state, federal, or other public agencies of jurisdiction for such discharge, will be used as the minimum requirements by the director of public utilities as applied to this chapter. (Prior code § 9-306)