Okla. Admin. Code § 785:46-15-2
The following words and terms, when used in this Subchapter, shall have the following meaning, unless the context clearly indicates otherwise:
"Ecoregion" means a geographical area within which ecosystems and the type, quality and quantity of environmental resources are generally similar, as more specifically described in EPA's 1997 revision of Omernick, "Ecoregions of the Conterminous United States", Annals of the Association of American Geographers.
"Impaired" means one or more designated beneficial uses are not being attained.
"MQL" means minimum quantification level.
"Non-wadable" means a stream which is not wadable.
"Rolling average" means the mathematical average of data values across a fixed length of time that incrementally changes its starting point but retains a fixed length of time by also incrementally changing its end point for each recalculation of the average. This term is also known as "moving average".
"Screening level" means an evaluation threshold based upon criteria prescribed in OAC 785:45 to protect a designated beneficial use.
"Seasonal base flow" means the sustained or fair-weather runoff, which includes but is not limited to groundwater runoff and delayed subsurface runoff.
"303(d) List" means the list of waterbodies with uses that are either threatened or impaired, developed for the State of Oklahoma in accordance with Section 303(d) of the federal Clean Water Act.
"305(b) Report" means the report of water quality in the State of Oklahoma developed in accordance with Section 305(b) of the federal Clean Water Act.
"Trophic State Index" means the results of the calculation for chlorophyll-a concentration using both Carlson, R.E. 1977, A Trophic State Index For Lakes, Limnology and Oceanography, 22:361-369 and the methods outlined in the Board guidance document "Guidance For Determining Lake Trophic State For Determination Of Nutrient Limited Waters Status".
"Wadable" means a stream or segment thereof, at least 10 percent of which under seasonal base flow conditions is:
(1) less than 1.25 meters deep at its thalweg, and
(2) has an instantaneous discharge of less than 10 cubic feet per second, or has a velocity of less than 10 centimeters per second.
"Waterbody" means a body of waters of the state.
Okla. Admin. Code § 785:46-15-2