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17.38.020 Definitions.

For the purposes of this Chapter, the following definitions apply:

A.  "Capacity" means the flow volume or rate for which a specific facility is designed to safely contain, receive, convey, infiltrate, or reduce pollutants from sanitary sewage, stormwater, wastewater, or other discharge in order to meet a specific performance standard.

B.  “Conveyance” means the transport of sanitary sewage, stormwater, wastewater or other discharge from one point to another point.

C.  "Director" means the Director of the Bureau of Environmental Services, or the Director’s designee.

D.  “Discharge” means any disposal, injection, dumping, spilling, pumping, emitting, emptying, leaching, leaking or placing of any material so that such material enters or is likely to enter a water body, groundwater, or a public sewer and drainage system.

E.  “Discharge Point” means the connection point of a site to a receiving system.

F.  “Discharge Rate” means the rate of flow of a discharge expressed in a unit of volume per unit of time.

G.  “Drainage Reserve” means the regulated area adjacent to and including a drainageway. A drainage reserve is required to protect the water quality and hydrology of the drainageway.

H.  "Drainageway" means a constructed or natural channel or depression that may at any time collect and convey water. A drainageway and its drainage reserve function together to manage flow rate, volume, and water quality. A drainageway may be permanently or temporarily inundated.

I.  “Groundwater” means subsurface water that occurs in soils and geological formations that are fully saturated.  Groundwater fluctuates seasonally and includes perched groundwater.

J.  “Groundwater Discharge” means a discharge of water pumped or directed from the ground. Groundwater discharges include but are not limited to subsurface water from site remediation and investigations, well development, Brownfield development, discharges from footing and foundation drains, and subsurface water associated with construction or property management dewatering activities.

K.  "Impervious Surface" means any surface that has a runoff coefficient greater than 0.8 (as defined in the City’s Sewer and Drainage Facilities Design Manual).  Types of impervious surfaces include rooftops, traditional asphalt and concrete parking lots, driveways, roads, sidewalks and pedestrian plazas. Slatted decks and gravel surfaces are considered pervious unless they cover impervious surfaces or unless gravels are compacted to a degree that causes their runoff coefficient to exceed 0.8.

L.  “Infiltration” means the percolation of water into the ground.  Infiltration is often expressed as a rate (unit of distance per unit of time) that is determined through an infiltration test.

M.  "Pollutants of Concern" means constituents identified by the Oregon Department of Environmental Quality or Bureau of Environmental Services (BES) as having the potential to have a negative impact on the receiving system. Pollutants of concern can include suspended solids, metals, nutrients, bacteria and viruses, organics, volatiles, semi-volatiles, floatable debris and increased temperature.

N.  "Practicable" means available and capable of being done as determined by the Director, after taking into consideration of factors such as cost, resources, existing technology, and logistics in light of overall project purpose.

O.  “Public Right-of-Way” means the area within the confines of a dedicated public street, an easement owned by the City, or other area dedicated for public use.

P.  “Receiving System” means any system that may receive stormwater or other discharges. Receiving systems include, but are not limited to: surface water bodies, groundwater, and sewer or drainage systems. 

Q.  "Redevelopment" means any development activity that requires demolition or removal of existing structures or impervious surfaces at a site and replacement with new impervious surfaces. Stormwater management requirements for redevelopment are found in the Stormwater Management Manual.

R.  “Source Control” means a structural or operational measure to prevent or control the release or potential release of pollutants generated by certain site characteristics and uses.

S.  “Stormwater” means water that originates as precipitation on a particular site, basin, or watershed.

T.  “Stormwater Management" means techniques used to reduce pollutants from, detain, retain, or provide a discharge point for stormwater. 

U.  "Stormwater Management Facility” means a facility or other technique used to reduce volume, flow rate or pollutants from stormwater. Stormwater management facilities may reuse, collect, convey, detain, retain, treat, or provide a discharge point for stormwater.

V.  “Temporary Structure” means a structure that is separate and distinct from all other structures and is created and removed in its entirety within three years, including all impervious area associated with the structure.

W.  "Tract" means a parcel of land designated as part of a land division per Title 33 that is not a lot, lot of record, or a public right-of-way.

X.  “Waters of the State” as defined by state law.

Y.  “Waters of the US” as jointly defined by the US Army Corps of Engineers and the Environmental Protection Agency.

Z.  "Wetland" means an area that is inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support, and that under normal circumstances does support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands include swamps, marshes, bogs, and similar areas except those constructed as pollution reduction or flow control facilities wholly outside Waters of the US and Waters of the State.

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