Section R. 323.1044 - Definitions; M to WRule 44. As used in this part:
(a) "Maximum acceptable toxicant concentration (MATC)" means the concentration obtained by calculating the geometric mean of the lower and upper chronic limits from a chronic test. A lower chronic limit is the highest tested concentration that did not cause the occurrence of a specific adverse effect. An upper chronic limit is the lowest tested concentration which did cause the occurrence of a specific adverse effect and above which all tested concentrations caused such an occurrence.(b) "Mixing zone" means the portion of a water body in which a point source discharge or venting groundwater is mixed with the receiving water.(c) "Natural water temperature" means the temperature of a body of water without an influence from an artificial source or a temperature as otherwise determined by the department.(d) "New discharge" means any building, structure, facility, or installation from which there is or may be a discharge of substances to the surface waters of the state, the construction of which commenced after July 29, 1997.(e) "No observed adverse effect level (NOAEL)" means the highest tested dose or concentration of a substance that results in no observed adverse effect in exposed test organisms where higher doses or concentrations result in an adverse effect.(f) "Nonpoint source" means a source of material to the surface waters of the state other than a source defined as a point source.(g) "Octanol-water partition coefficient (Kow)" means the ratio of the concentration of a substance in the n-octanol phase to its concentration in the aqueous phase in an equilibrated 2-phase octanol-water system. For log Kow, the log of the octanol-water partition coefficient is a base 10 logarithm.(h) "Palatable" means the state of being agreeable or acceptable to the sense of sight, taste, or smell.(i) "Partial body contact recreation" means any activities normally involving direct contact of some part of the body with water, but not normally involving immersion of the head or ingesting water, including fishing, wading, hunting, and dry boating.(j) "Plant nutrients" means the chemicals, including nitrogen and phosphorus, necessary for the growth and reproduction of aquatic rooted, attached, and floating plants, fungi, or bacteria.(k) "Point source" means a discharge that is released to the surface waters of the state by a discernible, confined, and discrete conveyance, including any of the following from which wastewater is or may be discharged:(vii) A discrete fissure.(ix) A concentrated animal feeding operation.(x) A boat or other watercraft.(l) "Public water supply sources" means the surface waters of the state at the point of water intake as identified in the publication "public water supply intakes in Michigan," dated December 9, 1999, and contiguous areas as the department determines necessary to assure protection of the source.(m) "Receiving waters" means the surface waters of the state into which an effluent is or may be discharged.(n) "Relative source contribution (RSC)" means the factor (percentage) used in calculating an HNV to account for all sources of exposure to a contaminant. The RSC reflects the percent of total exposure that can be attributed to surface water through water intake and fish consumption.(o) "Risk associated dose (RAD)" means a dose of a known or presumed carcinogenic substance, in milligrams per kilogram per day, that, over a lifetime of exposure, is estimated to be associated with a plausible upper bound incremental cancer risk equal to 1 in 100,000.(p) "Sanitary sewage" means treated or untreated effluent that contains human metabolic and domestic wastes.(q) "Significant industrial user (SIU)" means either of the following: (i) A nondomestic user subject to categorical pretreatment standards under 40 C.F.R. §403 (1992) and 40 C.F.R. chapter I, subchapter N (1990).(ii) A nondomestic user to which 1 of the following provisions applies: (A) The user discharges an average of 25,000 gallons per day or more of process wastewater to the publicly owned treatment works, excluding sanitary, noncontact cooling, and boiler blowdown wastewater.(B) The user contributes a process wastestream that makes up 5% or more of the average dry weather hydraulic or organic capacity of the publicly owned treatment works.(C) The user is designated as a significant industrial user by the control authority on the basis that the user has a potential for adversely affecting the publicly owned treatment works' operation or for violating any pretreatment standard or requirement. Upon a finding that a nondomestic user meeting the criteria in this subdivision has no reasonable potential for adversely affecting the publicly owned treatment works' operation or for violating any pretreatment standard or requirement, the control authority may, at any time, on its own initiative or in response to a petition received from a nondomestic user or publicly owned treatment works, determine that a nondomestic user is not a significant nondomestic user.(r) "Slope factor" means the incremental rate of cancer development calculated using a linearized multistage model or other appropriate model. It is expressed in milligrams per kilogram per day of exposure to the chemical in question and is also known as q1*.(s) "Standard" means a definite numerical value or narrative statement promulgated by the department to maintain or restore water quality to provide for, and fully protect, a designated use of the surface waters of the state.(t) "Subchronic effect" means an adverse effect, measured by assessing an acceptable endpoint resulting from continual exposure for a period of time less than the time deemed necessary for a chronic test.(u) "Surface waters of the state" means all of the following, but does not include drainage ways and ponds used solely for wastewater conveyance, treatment, or control: (i) The Great Lakes and their connecting waters.(viii) Other surface bodies of water within the confines of the state.(v) "Suspended solids" means the amount of materials suspended in water and is commonly expressed as a concentration in terms of milligrams per liter.(w) "Threshold effect" means an effect of a substance for which there is a theoretical or empirically established dose or concentration below which the effect does not occur.(x) "Total body contact recreation" means any activities normally involving direct contact with water to the point of complete submergence, particularly immersion of the head, with considerable risk of ingesting water, including swimming.(y) "Total maximum daily load (TMDL)" means an allowable pollutant loading to a surface water of the state as defined in R 323.1207.(z) "Toxic substance" means a substance, except for heat, that is present in sufficient a concentration or quantity that is or may be harmful to plant life, animal life, or designated uses.(aa) "Uncertainty factor (UF)" means one of several numeric factors used in operationally deriving criteria from experimental data to account for the quality or quantity of the available data.(bb) "Uptake" means the acquisition of a substance from the environment by an organism as a result of any active or passive process.(cc) "Venting groundwater" means groundwater that is entering a surface water of the state from a facility, as defined in section 20101 of 1994 PA 451, MCL 324.20101.(dd) "Warmwater fishery use" means the ability of a waterbody to support a balanced, integrated, adaptive community of fish species which thrive in relatively warm water, including any of the following:(ee) "Wasteload allocation (WLA)" means the allocation for an individual point source which ensures that the level of water quality to be achieved by the point source complies with these rules.(ff) "Wastewater" means any of the following: (i) Storm water runoff that could result in injury to a use designated in R 323.1100.(ii) Liquid waste resulting from commercial, institutional, domestic, industrial, and agricultural activities, including cooling and condensing waters.(gg) "Water quality value" means a tier I or tier II aquatic life or human health value or tier I wildlife value developed under R 323.1057.(hh) "Watershed" means the geographic region within which water drains into a particular river, stream, or body of water.(ii) "Wetland" means land characterized by the presence of water at a frequency and duration sufficient to support, and that under normal circumstances does support, wetland vegetation or aquatic life.(jj) "Whole effluent toxicity" means the total toxic effect of an effluent measured directly with a toxicity test under R 323.1219.(kk) "Wildlife use" means that a waterbody will not likely cause population-level impacts to mammalian and avian wildlife populations from lifetime exposure to the waterbody as a source of drinking water and aquatic food, consistent with the level of protection provided by these rules.(ll) "Wildlife value" means the maximum ambient water concentration of a substance at which adverse effects are not likely to result in population-level impacts to mammalian and avian wildlife populations from lifetime exposure through drinking water and aquatic food supply, using the methodology specified in R 323.1057(3).Mich. Admin. Code R. 323.1044
1979 AC; 1985 AACS; 1986 AACS; 1994 AACS; 1997 AACS; 2006 AACS