For use in these chapters, unless the context specifically indicates otherwise, the following terms are defined:
1. “B.O.D.” (denoting Biochemical Oxygen Demand) means the quantity of oxygen utilized in the biochemical oxidation of organic matter under standard laboratory procedure in five (5) days at twenty degrees (20º) C, expressed in milligrams per liter or parts per million.
2. “Building drain” means that part of the lowest horizontal piping of a building drainage system which receives the discharge from soil, waste, and other drainage pipes inside the walls of the building and conveys it to the building sewer, beginning five (5) feet (1.5 meters) outside the inner face of the building wall.
3. “Building sewer” means that part of the horizontal piping from the building wall to its connection with the main sewer or the primary treatment portion of an on-site wastewater treatment and disposal system conveying the drainage of one building site.
4. “Combined sewer” means a sewer receiving both surface run-off and sewage.
5. “Customer” means any person responsible for the production of domestic, commercial, or industrial waste which is directly or indirectly discharged into the public sewer system.
6. “Garbage” means solid wastes from the domestic and commercial preparation, cooking, and dispensing of food, and from the handling, storage, and sale of food products and produce.
7. “Industrial wastes” means solid, liquid, or gaseous substances from any industrial, manufacturing, commercial, or business establishment, or process, or from the development, recovery, or processing of any natural resource which any person discharges or allows to be discharged into the public sewer, but does not include any wastes from a building used exclusively for residential purposes which contains eight dwelling or rooming units or less.
8. “Inspector” means the person duly authorized by the Council to inspect and approve the installation of building sewers and their connections to the public sewer system; and to inspect such sewage as may be discharged therefrom.
9. “Natural outlet” means any outlet into a watercourse, pond, ditch, lake, or other body of surface or groundwater.
10. “On-site wastewater treatment and disposal system” means all equipment and devices necessary for proper conduction, collection, storage, treatment, and disposal of wastewater from four or fewer dwelling units or other facilities serving the equivalent of fifteen persons (1500 gpd) or less.
11. “Parts per million (ppm)” means a weight-to-weight ratio; the parts-per-million value multiplied by the factor 8.345 is equivalent to pounds per million gallons of water, and for the purposes of these Sanitary Sewer chapters, it means the same as milligrams per liter (mg/l).
12. “Paunch manure” means any material found in the stomachs or paunches of livestock.
13. “pH” means the logarithm of the reciprocal of the weight of hydrogen ions in grams per liter of solution.
14. “Public sewer” means a sanitary sewer provided by or under the jurisdiction of the City or a sewer provided by or under the jurisdiction of any other city or sewer district which ultimately discharges into a sewer under the jurisdiction of the City.
15. “Sanitary sewer” means a sewer that conveys sewage or industrial wastes or a combination of both, and into which storm, surface, and ground waters or unpolluted industrial wastes are not intentionally admitted.
16. “Sewage” means the water-carried human, animal, and household wastes in a public or private drain, together with such groundwater infiltration, surface drainage and industrial wastes as may be present.
17. “Sewage treatment plant” means the arrangement of devices and structures and equipment of the City of Des Moines for treating sewage and industrial wastes.
18. “Sewage works” means all facilities for collecting, pumping, treating, and disposing of sewage and industrial wastes.
19. “Sewer” means a pipe or conduit for carrying sewage or any other wastes liquids, including storm, surface, and ground water drainage.
20. “Slug” means any discharge of water, sewage, or industrial waste which in concentration of any given constituent or in quantity of flow exceeds for any period of duration longer than fifteen (15) minutes more than five (5) times the average 24-hour concentration or flows during normal operation.
21. “Standard methods” means the examination and analytical procedures set forth in the most recent edition of Standard Methods for the Examination of Water, Sewage, and Industrial Wastes, published jointly by the American Public Health Association, the American Water Works Association and the Water Pollution Control Federation.
22. “Storm drain” or “storm sewer” means a sewer which carries storm and surface waters and drainage but excludes sewage and industrial wastes, other than unpolluted cooling water.
23. “Storm water runoff” means that portion of rainfall that is drained into the sewers.
24. “Superintendent” means the Public Works Director of the City or any authorized deputy, agent, or representative.
25. “Suspended solids” means solids that either float on the surface of, or are in suspension in water, sewage, or other liquids, and which are removable by laboratory filtering.
26. “Unpolluted water or liquids” means any water or liquid containing none of the following: free or emulsified grease or oil; substances that may impart taste-and-odor or color characteristics; volatile, explosive, toxic, or poisonous substances in suspension, colloidal state, or solution; explosive, odorous, or otherwise obnoxious gases. Such water or liquids shall not contain more than 25 mg/l of suspended solids, and not more than 25 mg/l of B.O.D.
27. “Watercourse” means a channel in which a flow of water occurs, either continuously or intermittently.