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. 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 wastewater treatment process, constitute a hazard to humans or animals or create any hazard in the receiving waters of the wastewater treatment plant;

3. Any waters or wastes having a pH lower than 5.0 and having any other corrosive property capable of causing damage or hazard to structures, equipment and personnel of the wastewater treatment plant;

4. Any waters or wastes having a pH in excess of 10.0;

5. 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. Suspended solids concentrations shall be limited to two hundred fifty milligrams per liter per twenty-four-hour composite;

6. 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 approving authority that such wastes can harm either the sewers, wastewater treatment plant or equipment, have an adverse effect on the receiving stream, or can otherwise endanger life, limb, property or constitute a nuisance. In forming their 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 sewers, materials of construction of the sewers, nature of the wastewater treatment process, capacity of wastewater treatment plant, and other pertinent factors.

The substances prohibited are:

a. Any liquid or vapor having a temperature higher than one hundred fifty degrees Fahrenheit.

b. Any water or waste containing fats, wax, grease, or oils, whether emulsified or not, in excess of one hundred milligrams per liter or containing substances which may solidify or become viscous at temperatures between thirty-two and one hundred fifty degrees Fahrenheit, and which will or may cause obstruction to the flow in a sewer or other interference with the operation of the wastewater system.

c. Any commercial garbage that has not been properly shredded. The installation and operation of any commercial grinder equipped with a motor of one horsepower or greater shall be subject to the review and approval of the approving authority. A permit shall be obtained from the plumbing inspector prior to the installation of such commercial garbage grinder unit.

d. Any waters or wastes containing iron, copper, zinc, and similar objectionable or toxic substances; or wastes exerting an excessive chlorine requirement, to such a degree that any such material discharged in the composite wastewater to the sewer exceeds limits established by the approving authority for such materials.

e. Any waters or wastes discharged to the sewer containing over 0.1 milligrams per liter hexavalent chromium per twenty-four-hour composite.

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

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

h. Materials which exert or cause:

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

ii. Unusual volume of flow or concentration of wastes constituting "slugs" as defined in Section 12.08.010,

iii. 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 sulfate),

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

v. 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 the Department of Natural Resources, Division of Environmental Protection of the state.