Idaho Administrative Code › Title IDAPA 58 - Environmental Quality, Department of › Rule 58.01.02 - WATER QUALITY STANDARDS › Section 58.01.02.010 - DEFINITIONS

Current through August 31, 2023
For the purpose of the rules contained in IDAPA 58.01.02,
				"Water Quality Standards," the following definitions apply: (3-31-22)
01.
Activity
. For purposes of
			 antidegradation review, an activity that causes a discharge to a water subject
			 to the jurisdiction of the Clean Water Act. (3-31-22)
02.
Acute
. A stimulus severe
			 enough to induce a rapid response. In aquatic toxicity tests, acute refers to a
			 single or short-term (i.e., ninety-six (96) hours or less) exposure to a
			 concentration of a toxic substance or effluent which results in death to fifty
			 percent (50%) of the test organisms. When referring to human health, an acute
			 effect is not always measured in terms of lethality. (3-31-22)
03.
Acute Criteria
. Unless
			 otherwise specified in these rules, the maximum instantaneous or one (1) hour
			 average concentration of a toxic substance or effluent which ensures adequate
			 protection of sensitive species of aquatic organisms from acute toxicity due to
			 exposure to the toxic substance or effluent. Acute criteria are expected to
			 adequately protect the designated aquatic life use if not exceeded more than
			 once every three (3) years. This is also known as the Criterion Maximum
			 Concentration (CMC). There are no specific acute criteria for human health;
			 however, the human health criteria are based on chronic health effects and are
			 expected to adequately protect against acute effects. (3-31-22)
04.
Aquatic Species
. Any plant
			 or animal that lives at least part of its life in the water column or benthic
			 portion of waters of the state. (3-31-22)
05.
Assigned Criteria
. Criteria
			 associated with beneficial uses from Section
			 100 of these rules.
			 (3-31-22)
06.
Background
. The biological, chemical or physical condition of
			 waters measured at a point immediately upstream (up-gradient) of the influence
			 of an individual point or nonpoint source discharge. If several discharges to
			 the water exist or if an adequate upstream point of measurement is absent, the
			 Department will determine where background conditions should be measured.
			 (3-31-22)
07.
Basin Advisory
			 Group
. No less than one (1) advisory group named by the Director, in
			 consultation with the designated agencies, for each of the state's six (6)
			 major river basins which shall generally advise the Director on water quality
			 objectives for each basin, work in a cooperative manner with the Director to
			 achieve these objectives, and provide general coordination of the water quality
			 programs of all public agencies pertinent to each basin. Each basin advisory
			 group named by the Director reflect a balanced representation of the interests
			 in the basin and shall, where appropriate, include representatives from each of
			 the following: agriculture, mining, nonmunicipal point source discharge
			 permittees, forest products, local government, livestock, Indian tribes (for
			 areas within reservation boundaries), water-based recreation, and environmental
			 interests. (3-31-22)
08.
Beneficial Use
. Any of the various uses which may be made of the
			 water of Idaho, including, but not limited to, domestic water supplies,
			 industrial water supplies, agricultural water supplies, navigation, recreation
			 in and on the water, wildlife habitat, and aesthetics. The beneficial use is
			 dependent upon actual use, the ability of the water to support a non-existing
			 use either now or in the future, and its likelihood of being used in a given
			 manner. The use of water for the purpose of wastewater dilution or as a
			 receiving water for a waste treatment facility effluent is not a beneficial
			 use. (3-31-22)
09.
Best
			 Management Practice
. A practice or combination of practices, techniques
			 or measures developed, or identified, by the designated agency and identified
			 in the state water quality management plan which are determined to be the
			 cost-effective and practicable means of preventing or reducing the amount of
			 pollution generated by nonpoint sources to a level compatible with water
			 quality goals. (3-31-22)
10.
Bioaccumulation
. The process by which a compound is taken up by,
			 and accumulated in the tissues of an aquatic organism from the environment,
			 both from water and through food. (3-31-22)
11.
Bioaccumulative Pollutants
.
			 A compound with a bioaccumulation factor of greater than one thousand (1,000)
			 or a bioconcentration factor of greater than one thousand (1,000).
			 (3-31-22)
12.
Biological
			 Monitoring or Biomonitoring
. The use of a biological entity as a
			 detector and its response as a measure to determine environmental conditions.
			 Toxicity tests and biological surveys, including habitat monitoring, are common
			 biomonitoring methods. (3-31-22)
13.
Board
. The Idaho Board of
			 Environmental Quality. (3-31-22)
14.
Chronic
. A stimulus that
			 persists or continues for a long period of time relative to the life span of an
			 organism. In aquatic toxicity tests, chronic refers to continuous exposure to a
			 concentration of a toxic substance or effluent which results in mortality,
			 injury, reduced growth, impaired reproduction, or other adverse effect to
			 aquatic organisms. The test duration is long enough that sub-lethal effects can
			 be reliably measured. When referring to human health, a chronic effect is
			 usually measured in terms of estimated changes in rates (# of cases/ 1000
			 persons) of illness over a lifetime of exposure. (3-31-22)
15.
Chronic Criteria
. Unless
			 otherwise specified in these rules, the four (4) day average concentration of a
			 toxic substance or effluent which ensures adequate protection of sensitive
			 species of aquatic organisms from chronic toxicity due to exposure to the toxic
			 substance or effluent. Chronic criteria are expected to adequately protect the
			 designated aquatic life use if not exceeded more than once every three (3)
			 years. This is also known as the Criterion Continuous Concentration (CCC).
			 Human health chronic criteria are based on lifetime exposure.
			 (3-31-22)
16.
Compliance
			 Schedule or Schedule Of Compliance
. A schedule of remedial measures
			 including an enforceable sequence of actions or operations leading to
			 compliance with an effluent limitation, other limitation, prohibition, or
			 standard. (3-31-22)
17.
Cost-Effective and Reasonable Best Management Practices (BMPs) for
			 Nonpoint Sources
. All approved BMPs specified in Subsections
			 350.03 and
			 055.07 of these rules. BMPs for
			 activities not specified are, in accordance with Section
			 350, determined on a case-by-case
			 basis. (3-31-22)
18.
Daily
			 Maximum (Minimum)
. The highest (lowest) value measured during one (1)
			 calendar day or a twenty-four (24) hour period, as appropriate. For ambient
			 monitoring of dissolved oxygen, pH, and temperature, multiple measurements
			 should be obtained at intervals short enough that the difference between
			 consecutive measurements around the daily maximum (minimum) is less than zero
			 point two (0.2) ppm for dissolved oxygen, zero point one (0.1) SU for pH, or
			 zero point five (0.5) degree C for temperature. (3-31-22)
19.
Daily Mean
. The average of
			 at least two (2) appropriately spaced measurements, acceptable to the
			 Department, calculated over a period of one (1) day: (3-31-22)
a. Confidence bounds around the point
			 estimate of the mean may be required to determine the sample size necessary to
			 calculate a daily mean; (3-31-22)
b. If any measurement is greater or less than
			 five-tenths (0.5) times the average, additional measurements over the one-day
			 period may be needed to obtain a more representative average;
			 (3-31-22)
c. In calculating the
			 daily mean for dissolved oxygen, values used in the calculation shall not
			 exceed the dissolved oxygen saturation value. If a measured value exceeds the
			 dissolved oxygen saturation value, then the dissolved oxygen saturation value
			 will be used in calculating the daily mean. (3-31-22)
d. For ambient monitoring of temperature, the
			 daily mean should be calculated from equally spaced measurements, at intervals
			 such that the difference between any two (2) consecutive measurements does not
			 exceed one point zero (1.0) degree C. (3-31-22)