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For the purposes of this chapter, the following terms shall have the following meanings:


“AKART” means all known, available, and reasonable methods of prevention, control, and treatment.

“Applicable manual” means the Stormwater Management Manual for Western Washington (2012 manual as amended in 2014) prepared by the Washington State Department of Ecology in 2012 and amended in 2014.


“Best management practices (BMPs)” means the schedules of activities, prohibitions of practices, maintenance procedures, and structural and/or managerial practices approved by the Washington Department of Ecology that, when used singly or in combination, prevent or reduce the release of pollutants and other adverse impacts to waters of Washington State.


“City manager or his/her designee” means the city’s active appointed manager or an employee of the city that acts on his/her behalf.


“Development” means new development, redevelopment, or both.


“Ground water” means water in a saturated zone or stratum beneath the surface of the land or below a surface water body.


“Hard surface” means an impervious surface, a permeable pavement, or a vegetated roof.

“Hazardous materials” means any pollutant, contaminant, toxic or hazardous waste, dangerous substance, potentially dangerous substance, noxious substance, toxic substance, flammable material, explosive material, radioactive material, urea formaldehyde foam insulation, asbestos, PCBs, or any other substances the removal of which is required, or the manufacture, preparation, production, generation, use, maintenance, treatment, storage, transfer, handling, or shipment of which is restricted, prohibited, regulated, or penalized by any federal, state, county, or municipal statutes or laws.

“Hyperchlorinated” means water that contains a chlorine concentration exceeding 10 milligrams per liter.


“Illicit connection” means any manmade conveyance that is connected to the city’s storm and surface water system without a permit, excluding roof drains and other similar type connections.

“Illicit discharge” means any discharge to the city’s storm and surface water system that is not composed entirely of storm water except discharges pursuant to any nonmunicipal NPDES permit and discharges from fire-fighting activities.


“Land disturbing activity” means any activity that results in a change in the existing soil cover (both vegetative and nonvegetative) and/or the existing soil topography. Land disturbing activities include, but are not limited to, demolition, construction, clearing, grading, filling and excavation.

“Low impact development” or “LID” means a storm water and land use management strategy that strives to mimic predisturbance hydrologic processes of infiltration, filtration, storage, evaporation, and transpiration by emphasizing conservation, use of on-site natural features, site planning, and distributed storm water management practices that are integrated into a project design.

“Low impact development best management practices” or “LID BMPs” means distributed storm water management practices, integrated into a project design, that emphasize predisturbance hydrologic processes of infiltration, filtration, storage, evaporation and transpiration. LID BMPs include, but are not limited to, bioretention, rain gardens, permeable pavements, roof downspout controls, dispersion, soil quality and depth, vegetated roofs, minimum excavation foundations, and water reuse.


“New development” means land disturbing activities; structural development, including construction or installation of a building or other structure; creation of hard surfaces; and subdivision, short subdivision and binding site plans, as defined and applied in Chapter 58.17 RCW. Projects meeting the definition of “redevelopment” shall not be considered new development.

“NPDES” means the National Pollutant Discharge Elimination System, a national program for permitting and imposing pretreatment requirements related to the discharge of pollutants to surface waters of the state from point discharges. The permits are administered by the Washington Department of Ecology.


“On-site storm water management BMPs” are synonymous with LID BMPs.


“Pollutant” means any liquid, gaseous, solid, radioactive or other substance that when introduced into waters of the state will or is likely to create a nuisance or render such waters harmful, detrimental or injurious to the public health, safety or welfare, or to domestic, commercial, industrial, agricultural, recreational, or other legitimate beneficial uses, or to livestock, wild animals, birds, fish or other aquatic life.

“Pollution-generating impervious surface (PGIS)” means impervious surfaces considered to be a significant source of pollutants in storm water runoff. Such surfaces include those which are subject to: vehicular use; industrial activities (as further defined in the applicable manual); storage of erodible or leachable materials, wastes, or chemicals, and which receive direct rainfall or the run-on or blow-in of rainfall; metal roofs unless they are coated with an inert, nonleachable material (e.g., baked-on enamel coating); or roofs that are subject to venting significant amounts of dusts, mists, or fumes from manufacturing, commercial, or other indoor activities.


“Redevelopment” means, on a site that is already substantially developed (i.e., has 35 percent or more of existing hard surface coverage), the creation or addition of hard surfaces; the expansion of a building footprint or addition or replacement of a structure; structural development including construction, installation or expansion of a building or other structure; replacement of hard surface that is not part of a routine maintenance activity; and land disturbing activities.


“Storm and surface water system” means the entire system within the city, both public and private, naturally existing and manmade, for the drainage, conveyance, detention, treatment and storage of storm and surface waters.

“Storm water” means runoff during and following precipitation and snowmelt events, including surface runoff, drainage or interflow.

“Storm water facility” means a constructed component of a storm water system, designed or constructed to perform a particular function, or multiple functions. Storm water facilities include, but are not limited to, pipes, swales, ditches, culverts, street gutters, detention ponds, retention ponds, constructed wetlands, infiltration devices, catch basins, oil/water separators, and biofiltration swales.

“Storm water pollution prevention plan (SWPPP)” means a plan prepared for a site in accordance with applicable manual to control pollutants generated on the site that could enter waters of the state.

“Storm water treatment and flow control BMPs/facilities” means detention facilities, treatment BMPs/facilities, bioretention, vegetated roofs, and permeable pavements that help meet Minimum Requirement No. 6 (Runoff Treatment), Minimum Requirement No. 7 (Flow Control), or both according to the applicable manual.


“2012 manual (as amended in 2014)” means the Stormwater Management Manual for Western Washington prepared by the Washington State Department of Ecology in 2012 and amended in 2014. (Ord. 17C-09 § 1; Ord. 09C-09 § 1).