Oregon Administrative Rules › Chapter 340 - DEPARTMENT OF ENVIRONMENTAL QUALITY › Division 41 - WATER QUALITY STANDARDS: BENEFICIAL USES, POLICIES, AND CRITERIA FOR OREGON › Section 340-041-0002 - Definitions

Current through Register Vol. 63, No. 7, July 1, 2024
Definitions in this rule apply to all basins unless context
				requires otherwise.
(1) "401 Water
			 Quality Certification" means a determination made by DEQ that a dredge and fill
			 activity, private hydropower facility, or other federally licensed or permitted
			 activity that may result in a discharge to waters of the state has adequate
			 terms and conditions to prevent an exceedance of water quality criteria. The
			 federal permit in question may not be issued without this state determination
			 in accordance with the Federal Clean Water Act, section 401 (33 USC
			 1341).
(2) "Ambient Stream Temperature" means the
			 stream temperature measured at a specific time and place. The selected location
			 for measuring stream temperature must be representative of the stream in the
			 vicinity of the point being measured.
(3) "Anthropogenic," when used to describe
			 "sources" or "warming," means that which results from human activity.
(4) "Applicable Criteria" means the
			 biologically based temperature criteria in OAR 340-041-0028(4), the superseding
			 cold water protection criteria in 340-041-0028(11)  or the superseding natural
			 condition criteria in 340-041-0028(8). The applicable criteria may also be
			 site-specific criteria approved by U.S. EPA. A subbasin may have a combination
			 of applicable temperature criteria derived from some or all of these numeric
			 and narrative criteria.
(5)
			 "Appropriate Reference Site or Region" means a site on the same water body or
			 within the same basin or ecoregion that has similar habitat conditions and
			 represents the water quality and biological community attainable within the
			 areas of concern.
(6) "Aquatic
			 Species" means plants or animals that live at least part of their life cycle in
			 waters of the state.
(7) "Basin"
			 means a third-field hydrologic unit as identified by the U.S. Geological
			 Survey.
(8) "BOD" means 5-day,
			 20°C Biochemical Oxygen Demand.
(9) "Cold Water Species" means aquatic
			 organisms that are physiologically restricted to cold water including, but not
			 limited to, native salmon, steelhead, mountain whitefish, char including bull
			 trout, and trout.
(10) "Cold Water
			 Refugia" means those portions of a water body where or times during the diel
			 temperature cycle when the water temperature is at least 2 degrees Celsius
			 colder than the daily maximum temperature of the adjacent well-mixed flow of
			 the water body.
(11) "Commission"
			 or "EQC" means the Oregon Environmental Quality Commission.
(12) "Cool Water Species" means aquatic
			 organisms that are physiologically restricted to cool waters including, but not
			 limited to, native sturgeon, Pacific lamprey, suckers, chub, sculpins and
			 certain species of cyprinids (minnows.)
(13) "Core Cold Water Habitat Use" means
			 waters expected to maintain temperatures within the range generally considered
			 optimal for salmon and steelhead rearing, or that are suitable for bull trout
			 migration, foraging and sub-adult rearing that occurs during the summer. These
			 uses are designated on the following subbasin maps set out at OAR 340-041-0101  to 340-041-0340: Figures 130A, 151A, 160A, 170A, 180A, 201A, 220A, 230A, 271A,
			 286A, 300A, 310A, 320A, and 340A.
(14) "Critical Habitat" means those areas
			 that support rare, threatened, or endangered species or serve as sensitive
			 spawning and rearing areas for aquatic life as designated by the U.S. Fish and
			 Wildlife Service or National Oceanic and Atmospheric Administration-Fisheries
			 according to the Endangered Species Act (16 U.S. Code § 1531).
(15) "Daily Mean" for dissolved oxygen means
			 the numeric average of an adequate number of data to describe the variation in
			 dissolved oxygen concentration throughout a day, including daily maximums and
			 minimums. For calculating the mean, concentrations in excess of 100 percent of
			 saturation are valued at the saturation concentration.
(16) "Department" or "DEQ" means the Oregon
			 State Department of Environmental Quality.
(17) "Designated Beneficial Use" means the
			 purpose or benefit to be derived from a water body as designated by the Water
			 Resources Department or the Water Resources Commission.
(18) "DO" means dissolved oxygen.
(19) "Ecological Integrity" means the
			 summation of chemical, physical, and biological integrity capable of supporting
			 and maintaining a balanced, integrated, adaptive community of organisms having
			 a species composition, diversity, and functional organization comparable to
			 that of the natural habitat of the region.
(20) "Epilimnion" means the seasonally
			 stratified layer of a lake or reservoir above the metalimnion; the surface
			 layer.
(21) "Erosion Control Plan"
			 means a plan containing a list of best management practices to be applied
			 during construction to control and limit soil erosion.
(22) "Estuarine Waters" means all mixed fresh
			 and oceanic waters in estuaries or bays from the point of oceanic water
			 intrusion inland to a line connecting the outermost points of the headlands or
			 protective jetties.
(23) "High
			 Quality Waters" means those waters that meet or exceed levels necessary to
			 support the propagation of fish, shellfish and wildlife; recreation in and on
			 the water; and other designated beneficial uses.
(24) "Hypolimnion" means the seasonally
			 stratified layer of a lake or reservoir below the metalimnion; the bottom
			 layer.
(25) "Industrial Waste"
			 means any liquid, gaseous, radioactive, or solid waste substance or a
			 combination thereof resulting from any process of industry, manufacturing,
			 trade, or business or from the development or recovery of any natural
			 resources.
(26) "In Lieu Fee" means
			 a fee collected by a jurisdiction in lieu of requiring construction of onsite
			 stormwater quality control facilities.
(27) "Intergravel Dissolved Oxygen" (IGDO)
			 means the concentration of oxygen measured in the water within the stream bed
			 gravels. Measurements should be taken within a limited time period before
			 emergence of fry.
(28)
			 "Jurisdiction" means any city or county agency in the Tualatin River and Oswego
			 Lake subbasin that regulates land development activities within its boundaries
			 by approving plats or site plans or issuing permits for land
			 development.
(29) "Land
			 Development" means any human-induced change to improved or unimproved real
			 estate including, but not limited to, construction, installation or expansion
			 of a building or other structure; land division; drilling; or site alteration
			 such as land surface mining, dredging, grading, construction of earthen berms,
			 paving, improvements for use as parking or storage, excavation or
			 clearing.
(30) "Load Allocation" or
			 "LA" means the portion of a receiving water's loading capacity that is
			 attributed either to one of its existing or future nonpoint sources of
			 pollution or to natural background sources. Load allocations are best estimates
			 of the loading that may range from reasonably accurate estimates to gross
			 allotments, depending on the availability of data and appropriate techniques
			 for predicting loading. Whenever possible, natural and nonpoint source loads
			 should be distinguished.
(31)
			 "Loading Capacity" or "LC" means the greatest amount of loading that a water
			 body can receive without violating water quality standards.
(32) "Low Flow Period" means the flows in a
			 stream resulting primarily from groundwater discharge or base flows augmented
			 from lakes and storage projects during the driest period of the year. The dry
			 weather period varies across the state according to climate and topography.
			 Wherever the low flow period is indicated in Water Quality Management Plans,
			 this period has been approximated by the inclusive months. Where applicable in
			 a waste discharge permit, the low flow period may be further defined.
(33) "Managed Lakes" refers to lakes in which
			 hydrology is managed by controlling the rate or timing of inflow or
			 outflow.
(34) "Marine Waters" means
			 all oceanic, offshore waters outside of estuaries or bays and within the
			 territorial limits of the State of Oregon.
(35) "mg/l" or "mg/L" means milligrams per
			 liter.
(36) "Metalimnion" means the
			 seasonal, thermally stratified layer of a lake or reservoir that is
			 characterized by a rapid change in temperature with depth and that effectively
			 isolates the waters of the epilimnion from those of the hypolimnion during the
			 period of stratification; the middle layer.
(37) "Migration Corridors" mean those waters
			 that are predominantly used for salmon and steelhead migration during the
			 summer and have little or no anadromous salmonid rearing in the months of July
			 and August. Migration corridors are designated in Tables 101B and 121B and
			 Figures 151A, 170A, 300A and 340A under OAR 340-041-0101  to
			 340-041-0340.
(38) "Minimum" for
			 dissolved oxygen means the minimum recorded concentration including seasonal
			 and diurnal minimums.
(39) "Monthly
			 (30-day) Mean Minimum" for dissolved oxygen means the minimum of the 30
			 consecutive-day floating averages of the calculated daily mean dissolved oxygen
			 concentration.
(40) "Natural
			 Conditions" means conditions or circumstances affecting the physical, chemical,
			 or biological integrity of a water of the state that are not influenced by past
			 or present anthropogenic activities. Disturbances from wildfire, floods,
			 earthquakes, volcanic or geothermal activity, wind, insect infestation and
			 diseased vegetation are considered natural conditions.
(41) "Natural Thermal Potential" means the
			 determination of the thermal profile of a water body using best available
			 methods of analysis and the best available information on the site-potential
			 riparian vegetation, stream geomorphology, stream flows and other measures to
			 reflect natural conditions.
(42)
			 "Nonpoint Sources" means any source of water pollution other than a point
			 source. Generally, a nonpoint source is a diffuse or unconfined source of
			 pollution where wastes can either enter into waters of the state or be conveyed
			 by the movement of water into waters of the state.
(43) "Ocean Waters" means all oceanic,
			 offshore waters outside of estuaries or bays and within the territorial limits
			 of Oregon.
(44) "Outstanding
			 Resource Waters" means waters designated by the EQC where existing high quality
			 waters constitute an outstanding state or national resource based on their
			 extraordinary water quality or ecological values or where special water quality
			 protection is needed to maintain critical habitat areas.
(45) "Pollution" means such contamination or
			 other alteration of the physical, chemical, or biological properties of any
			 waters of the state, including change in temperature, taste, color, turbidity,
			 silt, or odor of the waters, or such discharge of any liquid, gaseous, solid,
			 radioactive, or other substance into any water of the state that either by
			 itself or in connection with any other substance present can reasonably be
			 expected to create a public nuisance or render such waters harmful,
			 detrimental, or injurious to public health, safety, or welfare; to domestic,
			 commercial, industrial, agricultural, recreational, or other legitimate
			 beneficial uses; or to livestock, wildlife, fish, other aquatic life or the
			 habitat thereof.
(46) "Point
			 Source" means a discernible, confined, and discrete conveyance including, but
			 not limited to, a pipe, ditch, channel, tunnel, conduit, well, discrete
			 fissure, container, rolling stock, concentrated animal feeding operation,
			 vessel or other floating craft, or leachate collection system from which
			 pollutants are or may be discharged. Point source does not include agricultural
			 storm water discharges and return flows from irrigated agriculture.
(47) "Public Water" means the same as "waters
			 of the state".
(48) "Public Works
			 Project" means any land development conducted or financed by a local, state, or
			 federal governmental body.
(49)
			 "Reserve Capacity" means that portion of a receiving stream's loading capacity
			 that has not been allocated to point sources or to nonpoint sources and natural
			 background as waste load allocations or load allocations, respectively. The
			 reserve capacity includes that loading capacity that has been set aside for a
			 safety margin and is otherwise unallocated.
(50) "Resident Biological Community" means
			 aquatic life expected to exist in a particular habitat when water quality
			 standards for a specific ecoregion, basin or water body are met. This must be
			 established by accepted biomonitoring techniques.
(51) "Salmon" means chinook, chum, coho,
			 sockeye and pink salmon.
(52)
			 "Salmon and Steelhead Spawning Use" means waters that are or could be used for
			 salmon and steelhead spawning, egg incubation, and fry emergence. These uses
			 are designated on the following subbasin maps set out at OAR 340-041-0101  to
			 340-041-0340: Tables 101B, and 121B, and Figures 130B, 151B, 160B, 170B, 220B,
			 230B, 271B, 286B, 300B, 310B, 320B, and 340B.
(53) "Salmon and Trout Rearing and Migration
			 Use" means thermally suitable rearing habitat for salmon, steelhead, rainbow
			 trout, and cutthroat trout as designated on subbasin maps set out at OAR
			 340-041-0101  to 340-041-0340: Figures 130A, 151A, 160A, 170A, 220A, 230A, 271A,
			 286A, 300A, 310A, 320A, and 340A.
(54) "Salmonid or Salmonids" means native
			 salmon, trout, mountain whitefish and char including bull trout. For purposes
			 of Oregon water quality standards, salmonid does not include brook or brown
			 trout because they are introduced species.
(55) "Secondary Treatment" means the
			 following depending on the context:
(a) For
			 sewage wastes, secondary treatment means the minimum level of treatment
			 mandated by U.S. Environmental Protection Agency regulations pursuant to
			 Public Law
			 92-500.
(b) For industrial and other waste sources,
			 secondary treatment means control equivalent to best practicable
			 treatment.