(1) “BOD (biochemical oxygen demand)” shall mean the quantity of oxygen utilized in the biochemical oxidation of organic matter under standard laboratory procedure in five days at 20 degrees centigrade, expressed in milligrams per liter.

(2) “Collection system” shall mean the system of public sewers to be operated by the city designed for the collection of sanitary sewage.

(3) “Commercial user” shall mean any premises used for commercial or business purposes which is not an industry as defined in this chapter.

(4) “Domestic waste” shall mean any wastewater emanating from dwellings or from domestic activities which are performed outside the home in lieu of a home activity directly by or for private citizens.

(5) “Industrial user” shall mean any nongovernmental user of the public treatment works that discharges more than the equivalent of 25,000 gallons per day (gpd) of sanitary wastes and which is identified in the Standard Industrial Classification Manual, 1972, Office of Management and Budget, as amended and supplemented under one of the following divisions:

Division A: Agriculture, Forestry, and Fishing

Division B: Mining

Division D: Manufacturing

Division E: Transportation, Communications, Electric, Gas, and Sanitary Services

Division I: Services

“Industrial user” also means any nongovernmental user of a publicly owned treatment works which discharges wastewater to the treatment works which contains toxic pollutants or poisonous solids, liquids, or gases in sufficient quantity either singly or by interaction with other wastes to contaminate the sludge of any municipal systems, or to injure or interfere with any sewage treatment process, or which constitutes a hazard to humans or animals, creates a public nuisance, or creates any hazard in or has an adverse effect on the waters receiving any discharge from the treatment works.

(6) “Industrial waste” shall mean that portion of the wastewater emanating from an industrial user which is not domestic waste or waste from sanitary conveniences.

(7) “Operation and maintenance” shall mean activities required to assure the dependable and economical function of treatment works and shall consist of:

(8) “Person” shall mean any individual, firm, company, association, society, corporation, or group.

(9) “Public treatment works” shall mean a treatment works owned and operated by a public authority.

(10) “Replacement” shall mean obtaining and installing equipment, accessories, or appurtenances which are necessary during the design or useful life, whichever is longer, of the treatment works to maintain the capacity and performance for which such works were designed and constructed.

(11) “Service area” shall mean all the area served by the treatment works and for which there is one uniform user charge system.

(12) “Sewage” shall mean a combination of water-carried wastes from residences, business buildings, institutions, and industrial establishments, together with such ground, surface, and stormwaters as may be present.

(13) “Sewage treatment plant” shall mean an arrangement of devices and structures used for treating sewage.

(14) “Shall” is mandatory; “may” is permissible.

(15) “Suspended solids” shall mean solids that either float on the surface or are in suspension in water, sewage, or other liquids, and which are removable by laboratory filtering.

(16) “Treatment works” shall mean all facilities for collecting, pumping, treating and disposing of sewage. “Treatment system” and “sewerage system” shall be equivalent terms for “treatment works.”

(17) “Useful life” shall mean the period during which a treatment works operates, as distinguished from “design life” which is the period during which a treatment works is planned and designed to be operated.

(18) “User” shall mean every person using any part of the public treatment works of the city of North Bend.