18 AAC 70.990 - Definitions

Current through September 28, 2021

Unless the context indicates otherwise, in this chapter

(1) "acute" means of, relating to, or resulting from a level of toxicity of a substance, a substance combination, or an effluent sufficient to produce observable lethal or sublethal effects in aquatic organisms exposed for short periods of time, typically 96 hours or less;
(2) "anadromous" with respect to fish, has the meaning given in the definition of "anadromous fish" in the definitions section of the Catalog of Waters Important for Spawning, Rearing, or Migration of Anadromous Fishes, adopted by reference in 5 AAC 95.011;
(3) "apparent color" means the condition of water that results in the visual sensations of hue and intensity, due both to substances in solution and to suspended matter;
(4) "aquaculture" means the cultivation of aquatic plants or animals for human use or consumption;
(5) "available evidence" means all relevant and applicable data and information the applicant has or can obtain, and all relevant and applicable data and information available to the department from other sources; "available evidence" does not include data and information that the collection or preparation of which, in the department's determination, is not practicable;
(6) "bioaccumulation" means the ability of a substance or chemical to be taken up by an organism either directly from exposure to a contaminated medium or by consumption of food containing the substance or chemical;
(7) "bioconcentration" means the ability of a substance or chemical to be absorbed from water through gills or epithelial tissue and concentrate in the body of an organism;
(8) "boundary" means a line or landmark that serves to clarify, outline, or mark a limit, border, or interface;
(9) "carcinogenic" means a substance that is expected to cause cancer in aquatic life or, for human health purposes, that is classified as a Group A or Group B carcinogen according to the United States Environmental Protection Agency Guidelines for Carcinogen Risk Assessment, 51 Fed. Reg. 33992, 33999 - 34000(1986); Group A includes substances that have been shown to cause cancer in humans; Group B, based on epidemiologic and other studies, includes "probable human carcinogens" and is divided between
(A) "B1", for which there is limited evidence of carcinogenicity in humans; and
(B) "B2", for which there is sufficient evidence of carcinogenicity in animals, but inadequate or no evidence of carcinogenicity in humans from epidemiologic studies;
(10) "certification" means the certificate of reasonable assurance the department may issue under 33 U.S.C. 1341 (Clean Water Act, sec. 401), as amended through February 4, 1987;
(11) "chronic" means of, relating to, or resulting from a level of toxicity of a substance, a substance combination, or an effluent sufficient to produce observable lethal or sublethal effects, including effects on growth, development, behavior, reproduction, or survival, in aquatic organisms exposed for a period of time that generally is one-tenth or more of their life span;
(12) "Clean Water Act" means the Federal Water Pollution Control Act (33 U.S.C. 1251 - 1387), as amended through February 4, 1987;
(13) "color" means the condition that results in the visual sensations of hue and intensity, as measured after turbidity is removed;
(14) "commissioner" means the commissioner of the Department of Environmental Conservation, or the commissioner's designee;
(15) "compensation point for photosynthetic activity" means the point at which incident light penetration allows plankton to photosynthetically produce enough oxygen to balance their respiration requirements;
(16) "contact recreation" means activities in which there is direct and intimate contact with water; "contact recreation" includes swimming, diving, and water skiing; "contact recreation" does not include wading;
(17) "criterion" means a set concentration or limit of a water quality parameter that, when not exceeded, will protect an organism, a population of organisms, a community of organisms, or a prescribed water use with a reasonable degree of safety; a criterion might be a narrative statement instead of a numerical concentration or limit;
(18) "department" means the Department of Environmental Conservation;
(19) "designated uses" means those uses specified in 18 AAC 70.020 as protected use classes for each waterbody or segment, regardless of whether those uses are being attained;
(20) "dissolved oxygen" means the concentration of oxygen in water as determined either by the Winkler (iodometric) method and its modifications or by the membrane electrode method;
(21) "cosystem" means a system made up of a community of animals, plants, and bacteria, and the system's interrelated physical and chemical environment;
(22) "effluent" means the segment of a wastewater stream that follows the final step in a treatment process and precedes discharge of the wastewater stream to the receiving environment;
(23) "EPA" means the United States Environmental Protection Agency;
(24) "existing uses" means those uses actually attained in a waterbody on or after November 28, 1975;
(25) "fecal coliform bacteria" means those bacteria that can ferment lactose at 44.5ø /+ 0.2ø C to produce gas in a multiple tube procedure; "fecal coliform bacteria" also means all bacteria that produce blue colonies within 24 /+ hours of incubation at 44.5ø /+ 0.2ø C in an M-FC broth medium;
(26) "fish" means any of the group of cold-blooded vertebrates that live in water and have permanent gills for breathing and fins for locomotion;
(27) "grain size accumulation graph" means a plot of sediment-sieving data showing logarithm of grain size in millimeters on the horizontal axis and percent accumulation by weight (linear scale) on the vertical axis;
(28) "ground water" means water in the zone of saturation; in this paragraph, "zone of saturation" is the zone below the water table, where all interstices are filled with water;
(29) "harmonic mean flow" means a long-term mean flow value calculated by dividing the number of daily flows analyzed by the sum of the reciprocals of those daily flows;
(30) repealed 3/23/2006;
(31) "industrial use" means use of a water supply for a manufacturing or production enterprise except food processing, and includes mining, placer mining, energy production, or development;
(32) "irreparable displacement" means a change in aquatic organism use or presence due to a decrease in water quality that is irreversible by natural processes so that the biological system will not return to a state functionally equivalent to the original after cessation of discharge;
(33) "lake" means an inland waterbody of substantial size that occupies a basin or hollow in the earth's surface and that might or might not have a current or a single direction of flow;
(34) "mean" means the average of values obtained over a specified time period and, for fecal coliform analysis, is computed as a geometric mean;
(35) "mean lower low water" means the tidal datum plane of the average of the lower of the two low waters of each day, as would be established by the National Geodetic Survey, at any place subject to tidal influence;
(36) "micrograms per liter (mg/l)" means the concentration at which one millionth of a gram (10-6 g) is found in a volume of one liter;
(37) "milligrams per liter (mg/l)" means the concentration at which one thousandth of a gram (10-3 g) is found in a volume of one liter; it is approximately equal to the unit "parts per million (PPM)," formerly of common use;
(38) "mixing zone" means a volume of water, adjacent to a discharge, in which wastes discharged mix with the receiving water;
(39) "most probable number (MPN)" means the statistic that represents the number of individuals most likely present in a given sample, based on test data;
(40) "mutagenic" means the ability of a substance or chemical to increase the frequency or extent of a significant and basic alteration in an organism's chromosomes or genetic material as determined according to the United States Environmental Protection Agency Guidelines for Mutagenicity Risk Assessment, 51 Fed. Reg. 34006 (1986), adopted by reference;
(41) "natural condition" means any physical, chemical, biological, or radiological condition existing in a waterbody before any human-caused influence on, discharge to, or addition of material to, the waterbody;
(42) "nonpoint source" means a source of pollution other than a point source;
(43) "oils and grease" means oils and grease as defined by the procedure used under 18 AAC 70.020(c) (1);
(44) "persist" means the ability of a substance or chemical not to decay, degrade, transform, volatilize, hydrolyze, or photolyze;
(45) "pH" means the negative logarithm of the hydrogen-ion concentration, expressed as moles per liter:

pH = -log10 (H+);

(46) "point source" means a discernible, confined, and discrete conveyance, including a pipe, ditch, channel, tunnel, conduit, well, container, rolling stock, or vessel or other floating craft, from which pollutants are or could be discharged;
(47) "pollution" has the meaning given that term in AS 46.03.900;
(48) "practicable" means available and capable of being done after taking into consideration cost, existing technology, and logistics in light of overall project purposes;
(49) "residues" means floating solids, debris, sludge, deposits, foam, scum, or any other material or substance remaining in a waterbody as a result of direct or nearby human activity;
(50) "secondary recreation" means activities in which incidental water use can occur; "secondary recreation" includes boating, camping, hunting, hiking, wading and recreational fishing; in this paragraph "recreational fishing" does not include fish consumption;
(51) "sediment" means solid material of organic or mineral origin that is transported by, suspended in, or deposited from water; "sediment" includes chemical and biochemical precipitates and organic material, such as humus;
(52) "settleable solids" means solid material of organic or mineral origin that is transported by and deposited from water, as measured by the volumetric Imhoff cone method and at the method detection limits specified in method 2540(F), in any edition of Standard Methods for the Examination of Water and Wastewater, adopted by reference in 18 AAC 70.020(c) (1);
(53) "sheen" means an iridescent appearance on the water surface;
(54) "significantly adverse levels" means concentrations of pollutants that would impair the productivity or biological integrity of the overall waterbody, including reducing or eliminating the viability or sustainability of a given species or community of species in the overall waterbody;
(55) "sodium adsorption ratio (SAR)" means the estimated degree to which sodium from a given water will be adsorbed in soil, as proposed in Diagnosis and Improvement of Saline and Alkali Soils, Agriculture Handbook No. 60, United States Salinity Laboratory Staff, United States Department of Agriculture, and is expressed as the quotient of the sodium ion concentration and the square root of half the sum of the calcium and magnesium ion concentrations:


(56) "spawning" means the process of producing, emitting, or depositing eggs, sperm, seed, germ, larvae, young, or juveniles, especially in large numbers, by aquatic life;
(57) "teratogenic" means the ability of a substance or chemical to cause developmental malformations and monstrosities, as determined according to the United States Environmental Protection Agency Guidelines for Health Assessment of Suspect Developmental Toxicants, 51 Fed. Reg. 34028 (1986), adopted by reference;
(58) "thermocline" means a zone of water between a warmer, surface zone and a colder, deep-water zone in a thermally stratified waterbody, in which water temperature decreases rapidly with depth;
(59) "total aqueous hydrocarbons (TAqH)" means those collective dissolved and water-accommodated monoaromatic and polynuclear aromatic petroleum hydrocarbons that are persistent in the water column; "total aqueous hydrocarbons" does not include floating surface oils or greases;
(60) "total aromatic hydrocarbons (TAH)" means the sum of the following volatile monoaromatic hydrocarbon compounds: benzene, ethylbenzene, toluene, and the xylene isomers, commonly called BETX;
(61) "toxic" means of, relating to, or resulting from a substance or substance combination that causes in affected organisms or their offspring
(A) death, disease, malignancy, genetic mutations;
(B) abnormalities, or malfunctions in growth, development, behavior, or reproduction; or
(C) other physical or physiological abnormalities or malfunctions;
(62) "toxic substances" means those substances or substance combinations, including disease-causing agents, which after discharge and upon exposure, ingestion, inhalation, or assimilation into an organism, either directly from the environment or indirectly by ingestion through food chains, will, on the basis of information available, cause a toxic effect in the affected organism or its offspring; "toxic substances" includes the following substances, and any other substance identified as a toxic pollutant under 33 U.S.C. 1317(a) (Clean Water Act, sec. 307(a)):

2-chlorophenol; 2,4-dichloraphenol; 2,4-dimethylphenol; acenaphthene; acrolein; acrylonitrile; Aldrin/Dieldrin; ammonia; antimony; arsenic; asbestos; benzene; benzidine; beryllium; cadmium; carbon tetrachloride; Chlordane; chlorinated benzenes; chlorinated naphthalene; chlorinated ethanes; chlorine; chloroalkyl ethers; chloroform; chlorophenols; chlorophenoxy herbicides; chromium; copper; cyanide; DDT; Demeton; dichlorobenzenes; dichlorobenzidine; dichloroethylenes; dichloropropane; dichloropropene; dinitrotoluene; diphenlyhydrazine; Endosulfan; Endrin; ethylbenzene; fluoranthene; Guthion; haloethers; halomethanes; Heptachlor; hexachlorobutadiene; hexachlorocyclohexane; hexachlorocyclopentadiene; isphorone; lead; Lindane; Malathion; mercury; methoxychlor; Mirex; napthalene; nickel; nitrobenzene; nitrophenols; nitrosamines; p-dioxin; Parathion; PCBs; pentachlorophenol; phenol; phthalate esters; polynuclear aromatic hydrocarbons; selenium; silver; tetrachloroethylene; thallium; toluene; Toxaphene; trichloroethylene; vinyl chloride; and zinc;

(63) "treatment works" has the meaning given that term in AS 46.03.900;
(64) "turbidity" means an expression of the optical property that causes light to be scattered and absorbed rather than transmitted in straight lines through a water sample; turbidity in water is caused by the presence of suspended matter such as clay, silt, finely divided organic and inorganic matter, plankton, and other microscopic organisms;
(65) "water," "waterbody," and "waters" have the meaning given the term "waters" in AS 46.03.900;
(66) "water of the United States" has the meaning given that term "water of the United States" in 40 C.F.R. 122.2, as amended through August 15, 1997;
(67) "water recreation" means contact recreation or secondary recreation;
(68) "water supply" means any of the waters of the state that are designated in this chapter to be protected for fresh water or marine water uses, including waters used for drinking, culinary, food processing, agricultural, aquacultural, seafood processing, and industrial purposes; "water supply" does not necessarily mean that a waterbody, protected as a supply for the uses listed in this paragraph is safe to drink in its natural state;
(69) "wildlife" means all species of mammals, birds, reptiles, and amphibians;
(70) "milliequivalents per liter" or "meq/l" mean milligrams per liter divided by the molecular weight of a chemical species, and multiplied by the electrical charge or valence of the species;
(71) "sodium percentage" means the quotient of (sodium x 100) divided by the sum of (sodium + calcium + magnesium + potassium); in this paragraph "sodium," "calcium," "magnesium," and "potassium" mean amounts of those substances expressed as milliequivalents per liter;
(72) "shellfish" means a species of crustacean, mollusk, or other aquatic invertebrate with a shell or shell-like exoskeleton, in any stage of its life cycle.
(73) "Colony forming unit (CFU)" means a measurement for microbial growth reported as colony forming units per 100 ml of water (CFU/100 ml); a colony of bacteria means a mass of one or more individual cells of the same organism, growing together.
(74) "assimilative capacity" means
(A) the increment of water quality that is better than the applicable criteria; or
(B) the capacity of a specific water to accommodate the addition of a parameter without causing violations of applicable water quality criteria, impairing water quality, or negatively impacting uses;
(75) "new or expanded," with respect to discharges, means discharges that are regulated for the first time or discharges that are expanded such that they could result in an increase in permitted parameter load or concentration or other changes in discharge characteristics that could lower water quality or have other adverse environmental impacts;
(76) "parameter" means any chemical, physical, or biological characteristic of water, including a pollutant as defined under 18 AAC 83.990;
(77) "receiving water" means the water, or segment of the water, to which a discharge occurs or is proposed to occur;
(78) "sufficient and credible" means scientifically valid chemical, physical, or biological data that
(A) is of adequate quantity and quality; and
(B) is collected under a sampling and analysis plan, including quality assurance and quality control procedures, and addressing spatial and temporal coverage, as applicable.
(79) "water quality standards variance" means a time-limited designated use and criterion
(A) for one or more specific pollutants or water quality parameters; and
(B) that reflect the highest attainable condition during the term of the writer quality standard variance.


18 AAC 70.990
Eff. 11/1/97, Register 143; am 4/29/99, Register 150; am 6/22/2003, Register 166; am 3/23/2006, Register 177; am 6/13/2006, Register 178; am 2/5/2017, Register 221, April 2017; am 4/6/2018, Register 226, July 2018; am 3/5/2020, Register 233, April 2020

Authority: AS 46.03.010

AS 46.03.020

AS 46.03.050

AS 46.03.070

AS 46.03.080

AS 46.03.100

AS 46.03.110

AS 46.03.710

AS 46.03.720

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