AIR GAP: A physical vertical separation through the free atmosphere sufficient to prevent backflow between the free-flowing discharge end of the potable water system and the overflow level of the receiving vessel, tank, plumbing fixture, or any other system. Physically defined as a distance greater than or equal to twice the diameter of the supply pipe diameter, but in no case less than one inch (1"). (Ord. 4312, 5-13-1991)

APPROVED: (for purposes of the Water Utility Provisions) Approved in writing by the Washington State Department of Health or other agency having jurisdiction. (Ord. 4312, 5-13-1991)

AUXILIARY SUPPLY: Any water source or system on or available to the premises other than the purveyor approved potable water supply. (Ord. 4312, 5-13-1991)

BACKFLOW: The flow of water or any other liquid, gas, or substance from any source back into the distribution pipes of the potable water supply system. (Ord. 4312, 5-13-1991)

BACKFLOW PREVENTER: An approved assembly which prevents the backflow of water or any other liquid, gas, or substance from any source back into the distribution pipes of the potable water supply system. (Ord. 4312, 5-13-1991)

BACKSIPHONAGE: The flow of water or any other liquid, gases, or substances from any source back into the distribution pipes of the potable water supply system caused by the reduction of pressure in the potable water supply system. (Ord. 4312, 5-13-1991)

BEST MANAGEMENT PRACTICES (BMPs): The methods of improving stormwater quality by preventing or reducing the discharge of pollutants, directly or indirectly, into stormwater, surface water, and groundwater. Such practices encompass a variety of managerial, operational, and structural measures that will reduce the amount of contaminants in stormwater and improve the quality of water resources. BMPs are separated into two (2) broad categories: source control and treatment. Source control BMPs prevent contaminants from entering water bodies or stormwater runoff. Treatment BMPs are structures that treat stormwater to remove contaminants. See also RMC 4-11-020 for BEST MANAGEMENT PRACTICES – WETLANDS. (Ord. 5478, 8-3-2009)

BMPs: See BEST MANAGEMENT PRACTICES (BMPs), supra, and RMC 4-11-020. (Ord. 5478, 8-3-2009)

BUILDING DRAIN: That part of the lowest horizontal piping of a 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 feet (5') outside the inner face of the building walls. (Ord. 4343, 2-3-1992)

BUILDING SEWER: See “Sewer, Building.” (Ord. 4343, 2-3-1992)

BUSINESS: A general term for publicly and privately owned institutional, commercial, and industrial sites which have the potential to generate pollutants to the municipal separate storm sewer system (MS4). This includes multi-family housing developments (e.g., apartment developments, condominium developments).

COMBINED SEWER: A sewer receiving both surface runoff and sewage. (Ord. 4343, 2-3-1992)

CONTAMINANT: A substance that will impair the quality of the water to a degree that it creates a serious health hazard. (Ord. 4312, 5-13-1991)

CROSS CONNECTION: Any physical or potential arrangement whereby a public water system is connected, directly or indirectly, with any other nonpotable water system, drain, sewer, conduit, pool, storage reservoir, plumbing fixture, or other device which contains, or may contain, contaminated water, sewer, or other waste liquid of unknown or unsafe quality which may be capable of imparting contamination to the public water system as a result of backflow. Bypass arrangements, jumper connections, removable sections, swivel or change-over devices, or other temporary or permanent devices through which backflow may occur are considered to be cross connections. (Ord. 4312, 5-13-1991)

DOUBLE CHECK VALVE ASSEMBLY: An approved assembly composed of two (2) single, independently acting check valves, either spring loaded or internally weighted, installed as a unit between two (2) tightly closing shutoff valves and having suitable connections for testing. (Ord. 4312, 5-13-1991)

FWPCA: The Federal Water Pollution Control Act of 1956, PL 84-660, together with the amendments of 1966, 1972, and as same may be hereafter amended; Public Law 92-500 and all subsequent amendments thereto. (Ord. 4343, 2-3-1992)

HEALTH HAZARD: A physical or toxic hazard which could be dangerous to health. (Ord. 4312, 5-13-1991)

ILLICIT CONNECTION: Any infrastructure connection to the municipal stormwater sewer system that is not intended, permitted, or used for collecting and conveying stormwater or non-stormwater discharges allowed as specified in RMC 4-6-030. Examples include sanitary sewer connections, floor drains, channels, pipelines, conduits, inlets, or outlets that are connected directly to the MS4. (Ord. 5478, 8-3-2009; Ord. 5873, 1-8-2018)

ILLICIT DISCHARGE: Any discharge to the MS4 that is not composed entirely of stormwater or of non-stormwater discharges allowed as specified in RMC 4-6-030. This includes discharges resulting from inadequate implementation of source control BMPs. (Ord. 5478, 8-3-2009; Ord. 5873, 1-8-2018)

INDUSTRIAL WASTES: The liquid wastes from industrial process as distinct from sanitary sewage. (Ord. 4343, 2-3-1992)

INFILTRATION: The volume of water or groundwater entering sewers and building sewer connections from the soil through defective joints, broken or cracked pipe, improper connections, or other structural failures. (Ord. 4343, 2-3-1992)

LONG-RANGE WASTEWATER MANAGEMENT PLAN: See City Comprehensive Sewer Plan. (Ord. 4343, 2-3-1992)

MS4: See “Municipal Separate Storm Sewer System.” (Ord. 5478, 8-3-2009)

MUNICIPAL SEPARATE STORM SEWER SYSTEM: A conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, manmade channels, or storm drains):

a. Owned or operated by the City of Renton;

b. Designed or used for collecting or conveying stormwater;

c. Which is not part of a publicly owned treatment works (POTW) as defined at 40 CFR 403.3(q);

d. Which is not a combined sewer; and

e. Which is defined as “large” or “medium” or “small” or otherwise designated by Ecology pursuant to 40 CFR 122.26. (Ord. 5478, 8-3-2009; Ord. 5873, 1-8-2018)

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) STORMWATER DISCHARGE PERMIT: A permit issued by the Environmental Protection Agency (EPA) (or by Ecology under authority delegated pursuant to 33 U.S.C. Section 1342(b)) that authorizes the discharge of pollutants to waters of the United States, whether the permit is applicable on an individual, group, or general area-wide basis. (Ord. 5478, 8-3-2009)

NATURAL OUTLET: Any outlet into a watercourse, pond, ditch, lake, or other body of surface or groundwater. (Ord. 4343, 2-3-1992)

NPDES: See “National Pollutant Discharge Elimination System (NPDES) Stormwater Discharge Permit.” (Ord. 5478, 8-3-2009)

POTABLE WATER: Water which is safe for human consumption, as described by the public health authority having jurisdiction. (Ord. 4312, 5-13-1991)

POTW: See “Publicly Owned Treatment Works.” (Ord. 5478, 8-3-2009)

PRESSURE VACUUM BREAKER: An assembly consisting of a spring loaded check valve and independently operating air inlet valve, inlet and discharge shutoff valve, and properly installed test cocks. The air inlet valve is internally loaded to the open position, normally by means of a spring. This internal loading allows the assembly to be installed on the pressure side of a shutoff valve. It is designed to protect against backsiphonage only. (Ord. 4312, 5-13-1991)

PUBLICLY OWNED TREATMENT WORKS: Any device or system used in treatment of municipal sewage or industrial wastes of a liquid nature which is publicly owned. (Ord. 5478, 8-3-2009)

REDUCED PRESSURE PRINCIPLE BACKFLOW PREVENTER: An assembly consisting of two (2) independently acting spring operated check valves, separated by a spring loaded differential pressure relief valve, which is installed as a unit between two (2) tightly closing shutoff valves and having suitable connections for testing. (Ord. 4312, 5-13-1991)

SEWAGE: A combination of the water-carried wastes from residences, commercial buildings, institutions, and industrial establishments, together with such ground, surface, and stormwaters as may be present. (Ord. 4343, 2-3-1992)

SEWAGE TREATMENT PLANT: Any arrangement of devices and structures used for treating sewage.

SEWAGE WORKS: All facilities for collecting, pumping, treating, and disposing of sewage.

SEWER: A pipe or conduit for carrying sewage.

SEWER, BUILDING: The extension from the building drain to the public sewer or other place of disposal.

SEWER, PUBLIC: That portion of a sanitary sewer and its appurtenances located on property, easements, and rights-of-way held, owned, controlled, and accepted by the City or other public authority.

SEWER, SANITARY: A sewer which carries sewage and to which storm, surface, and groundwaters are not intentionally admitted.

SIDE SEWER: See “Sewer, Building.”

SIDE SEWER STUB: That portion of the building sewer between primary collection lines and individual property lines.

SOURCE CONTROL: A practice to implement preventative measures to stop pollution before it enters the MS4 and subsequently flows to receiving waters. Source control aims to address accumulation of non-point source pollutants such as fertilizers, oil and grease, washwater, etc., that originate from daily business/site activities, spill incidents, improper disposal, or other indirect sources.

SOURCE CONTROL BEST MANAGEMENT PRACTICES (BMPs): A structural or nonstructural BMP intended to prevent contaminants from entering surface water, stormwater, or groundwater including the modification of processes to eliminate the production or use of contaminants. Structural source control BMPs involve the construction of a physical structure on site, or other type of physical modification to a site (e.g., a covered storage area); nonstructural source control involves the modification or addition of managerial or behavioral practices.

SOURCE CONTROL INSPECTION: A site visit, or follow-up, conducted by the Public Works Administrator to assess compliance with source control requirements.

STORM SEWER and STORM DRAIN: A sewer which carries storm and surface waters and drainage, but excludes sewage and polluted industrial wastes.

STORMWATER: Runoff during and following precipitation and snowmelt events, including surface runoff, drainage, or interflow. (Ord. 5873, 1-8-2018)

WATERCOURSE: A channel in which a flow of water occurs either continuously or intermittently. (Ord. 4343, 2-3-1992; Ord. 6074, 7-18-2022)