Section 327IAC2-1.5-2. Definitions

   In addition to the definitions contained in IC 13-11-2 and 327 IAC 1, the following definitions apply throughout this article, 327 IAC 5, and 327 IAC 15:

(1) "Acceptable daily exposure" or "ADE" means an estimate of the maximum daily dose of a substance that is not expected to result in adverse noncancer effects to the general human population, including sensitive subgroups.

(2) "Acceptable endpoints" (subchronic and chronic), for the purpose of wildlife criteria derivation, means those endpoints that affect reproductive or developmental success, organismal viability or growth, or any other endpoint that is, or is directly related to, a parameter that influences population dynamics.

(3) "Acute-chronic ratio" or "ACR" means a standard measure of the acute toxicity of a material divided by an appropriate measure of the chronic toxicity of the same material under comparable conditions.

(4) "Acute toxicity" means concurrent and delayed adverse effects that result from an acute exposure and occur within any short observation period, which begins when the exposure begins, may extend beyond the exposure period, and usually does not constitute a substantial portion of the life span of the organism.

(5) "Acute toxic unit" or "TU_a" means 100/LC₅₀ where the LC₅₀ is expressed as a percent effluent in the test medium of an acute whole effluent toxicity (WET) test that is statistically or graphically estimated to be lethal to fifty percent (50%) of the test organisms.

(6) "Adverse effect" means any deleterious effect to organisms due to exposure to a substance. The term includes effects that are or may become debilitating, harmful, or toxic to the normal functions of the organism, but does not include nonharmful effects, such as tissue discoloration alone or the induction of enzymes involved in the metabolism of the substance.

(7) "Alternate mixing zone" means a mixing zone granted by the commissioner under 327 IAC 5-2-11.4(b)(4) for a particular pollutant and a particular criterion or value that is larger than that specified in 327 IAC 5-2-11.4(b)(2) or 327 IAC 5-2-11.4(b)(3).

(8) "Baseline BAF" means the following:

(A) For organic chemicals, a BAF that is based on the concentration of freely dissolved chemical in the ambient water and takes into account the partitioning of the chemical within the organism.

(B) For inorganic chemicals, a BAF that is based on the wet weight of the tissue.

(9) "Baseline BCF" means the following:

(A) For organic chemicals, a BCF that is based on the concentration of freely dissolved chemical in the ambient water and takes into account the partitioning of the chemical within the organism.

(B) For inorganic chemicals, a BCF that is based on the wet weight of the tissue.

(10) "Bioaccumulation" means the net accumulation of a substance by an organism as a result of uptake from all environmental sources.

(11) "Bioaccumulation factor" or "BAF" means the ratio (in L/kg) of a substance’s concentration in tissue of an aquatic organism to its concentration in the ambient water, in situations where both the organism and its food are exposed and the ratio does not change substantially over time.

(12) "Bioaccumulative chemical of concern" or "BCC" has the meaning set forth in section 6 of this rule.

(13) "Bioconcentration" means the net accumulation of a substance by an aquatic organism as a result of uptake directly from the ambient water through gill membranes or other external body surfaces.

(14) "Bioconcentration factor" or "BCF" means the ratio (in liters per kilogram) of a substance’s concentration in tissue of an aquatic organism to its concentration in the ambient water, in situations where the organism is exposed through the water only and the ratio does not change substantially over time.

(15) "Biota-sediment accumulation factor" or "BSAF" means the ratio (in kilograms of organic carbon per kilogram of lipid) of a substance’s lipid-normalized concentration in tissue of an aquatic organism to its organic carbon-normalized concentration in surface sediment, in situations where:

(A) the ratio does not change substantially over time;

(B) both the organism and its food are exposed; and

(C) the surface sediment is representative of average surface sediment in the vicinity of the organism.

(16) "Carcinogen" means a substance that causes an increased incidence of benign or malignant neoplasms, or substantially decreases the time to develop neoplasms, in animals or humans. The classification of carcinogens is discussed in section 14(b)(1) of this rule.

(17) "Chronic effect", for purposes of wildlife criteria derivation, means:

(A) an adverse effect that is measured by assessing an acceptable endpoint; and

(B) results from continual exposure over several generations, or at least over a significant part of the test species’ projected life span or life stage.

(18) "Chronic toxicity" means concurrent and delayed adverse effects that occur only as a result of a chronic exposure.

(19) "Chronic toxic unit" or "TU_c" means 100/NOEC or 100/IC₂₅, where the NOEC and IC₂₅ are expressed as a percent effluent in the test medium.

(20) "Clean Water Act" or "CWA" means the federal Water Pollution Control Act, as amended (33 U.S.C. 1251 et seq.).

(21) "Coliform bacteria" means all the aerobic and facultatively anaerobic, gram-negative, nonsporeforming bacilli that produce acid and gas from the fermentation of lactose.

(22) "Community" means a general collective term to describe the varieties of aquatic species and associated organisms living together in a waterbody.

(23) "Criteria conversion factors" refers to the conversion factors that are multiplied by acute and chronic aquatic criteria developed using toxicological data in the form of total recoverable metal to express the criteria in the form of dissolved metal. The conversion factor for a particular metal and criterion is the fraction of the metal corresponding to an estimate of the percent of the total recoverable metal that was dissolved in the aquatic toxicity tests that were most important in the derivation of the criterion for the metal.

(24) "Criterion" means a definite numerical value or narrative statement promulgated by the water pollution control board to maintain or enhance water quality to provide for and fully protect designated uses of the waters of the state.

(25) "Criterion continuous concentration" or "CCC" means an estimate of the highest concentration of a material in the water column to which an aquatic community can be exposed indefinitely without resulting in an unacceptable effect.

(26) "Criterion maximum concentration" or "CMC" means an estimate of the highest concentration of a material in the water column to which an aquatic community can be exposed briefly without resulting in an unacceptable effect.

(27) "Depuration" means the loss of a substance from an organism as a result of any active or passive process.

(28) "Designated uses" has the meaning set forth in section 5 of this rule, whether or not they are being attained.

(29) "EC₅₀" refers to a statistically or graphically estimated concentration that is expected to cause one (1) or more specified effects in fifty percent (50%) of a group of organisms under specified conditions.

(30) "Effluent" means a wastewater discharge from a point source to the waters of the state.

(31) "Endangered or threatened species" includes those species that are listed as endangered or threatened under Section 4 of the Endangered Species Act (ESA).

(32) "ESA" means the Endangered Species Act (ESA), 16 U.S.C. 1531 et seq.

(33) "Existing uses" includes those uses actually attained in the waterbody on or after November 28, 1975, whether or not they are included under section 5 of this rule.

(34) "Final acute value" or "FAV" means:

(A) a calculated estimate of the concentration of a test material such that ninety-five percent (95%) of the genera (with which acceptable acute toxicity tests have been conducted on the material) have higher GMAVs; or

(B) the SMAV of an important or critical species, if the SMAV is lower than the calculated estimate.

(35) "Final chronic value" or "FCV" means:

(A) a calculated estimate of the concentration of a test material such that ninety-five percent (95%) of the genera (with which acceptable chronic toxicity tests have been conducted on the material) have higher GMCVs;

(B) the quotient of an FAV divided by an appropriate acute-chronic ratio; or

(C) the SMCV of an important or critical species, if the SMCV is lower than the calculated estimate or the quotient, whichever is applicable.

(36) "Final plant value" or "FPV" means the lowest plant value that was obtained with an important aquatic plant species in an acceptable toxicity test for which the concentrations of the test material were measured and the adverse effect was biologically important.

(37) "Food-chain multiplier" or "FCM" means the ratio of a BAF to an appropriate BCF.

(38) "Full body contact" means direct contact with the water to the point of complete submergence.

(39) "Genus mean acute value" or "GMAV" means the geometric mean of the SMAVs for the genus.

(40) "Genus mean chronic value" or "GMCV" means the geometric mean of the SMCVs for the genus.

(41) "Geometric mean" means the Nth root of the product of N quantities. Alternatively, the geometric mean can be calculated by adding the logarithms of the N numbers, dividing the sum by N, and taking the antilog of the quotient.

(42) "Great Lakes" means Lake Erie and Lake Michigan.

(43) "Great Lakes states" means:

(A) Illinois;

(B) Indiana;

(C) Michigan;

(D) Minnesota;

(E) New York;

(F) Ohio;

(G) Pennsylvania; and

(H) Wisconsin.

(44) "Great Lakes system" means all the streams, rivers, lakes, and other waters of the state within the drainage basin of the Great Lakes within Indiana.

(45) "Great Lakes water quality wildlife criterion" or "GLWC" means the concentration of a substance that is likely to, if not exceeded, protect avian and mammalian wildlife populations inhabiting the Great Lakes basin from adverse effects resulting from the ingestion of water and aquatic prey taken from surface waters of the Great Lakes system. These criteria are based on existing toxicological studies of the substance of concern and quantitative information about the exposure of wildlife species to the substance, that is, food and water consumption rates. Since toxicological and exposure data for individual wildlife species are limited, a GLWC is derived using a methodology similar to that used to derive noncancer human health criteria. Separate avian and mammalian values are developed using taxonomic class-specific toxicity data and exposure data for five (5) representative Great Lakes basin wildlife species. The following wildlife species selected are representative of avian and mammalian species resident in the Great Lakes basin that are likely to experience the highest exposures to bioaccumulative contaminants through the aquatic food web:

(A) Bald eagle.

(B) Herring gull.

(C) Belted kingfisher.

(D) Mink.

(E) River otter.

(46) "Ground water" means water located below the ground surface in interconnected voids and pore spaces in the zone of saturation.

(47) "High quality waters" means waterbodies in which, on a parameter by parameter basis, the quality of the waters exceeds levels necessary to support propagation of fish, shellfish, and wildlife and recreation in and on the water. The term includes any waterbody for which the pollutant has not been detected in:

(A) the water column; and

(B) nontransient aquatic organisms at levels that would indicate that a water quality criterion is not being met.

(48) "Human cancer criterion" or "HCC" refers to a human cancer value (HCV) for a pollutant that meets the minimum data requirements for Tier I specified in section 14 of this rule.

(49) "Human cancer value" or "HCV" means the maximum ambient water concentration of a substance at which a lifetime of exposure will represent a plausible upper-bound risk of contracting cancer of one (1) in one hundred thousand (100,000) using the exposure assumptions specified in section 14 of this rule from either:

(A) drinking the water, consuming fish from the water, and water-related recreational activities; or

(B) consuming fish from the water and water-related recreational activities.

(50) "Human noncancer criterion" or "HNC" refers to a human noncancer value (HNV) for a pollutant that meets the minimum data requirements for Tier I specified in section 14 of this rule.

(51) "Human noncancer value" or "HNV" means the maximum ambient water concentration of a substance at which adverse noncancer effects are not likely to occur in the human population from lifetime exposure using section 14 of this rule from either:

(A) drinking the water, consuming fish from the water, and water-related recreational activities; or

(B) consuming fish from the water and water-related recreation activities.

(52) "Inhibition concentration 25" or "IC₂₅" means the toxicant concentration that would cause a twenty-five percent (25%) reduction in a nonquantal biological measurement for the test population. For example, the IC₂₅ is the concentration of toxicant that would cause a twenty-five percent (25%) reduction in mean young per female or in growth for the test population.

(53) "LC₅₀" refers to a statistically or graphically estimated concentration that is expected to be lethal to fifty percent (50%) of a group of organisms under specified conditions.

(54) "Linearized multistage model" means a conservative mathematical model for cancer risk assessment. This model fits linear dose-response curves to low doses. It is consistent with a no-threshold model of carcinogenesis, that is, exposure to even a very small amount of the substance is assumed to produce a finite increased risk of cancer.

(55) "Lowest observed adverse effect level" or "LOAEL" means the lowest tested dose or concentration of a substance that resulted in an observed adverse effect in exposed test organisms when all higher doses or concentrations resulted in the same or more severe effects.

(56) "Maximum contaminant level" or "MCL" means the maximum permissible level of a contaminant in water that is delivered to the free-flowing outlet of the ultimate user of a public water system.

(57) "Mixing zone" means an area contiguous to a discharge where the discharged wastewater mixes with the receiving water. Where the quality of the effluent is lower than that of the receiving water, it may not be possible to attain within the mixing zone all beneficial uses attained outside the zone. The mixing zone should not be considered a place where effluents are treated.

(58) "New Great Lakes discharger" has the meaning set forth in 327 IAC 5-1.5-36.

(59) "Nonthreshold mechanism" means a process that results in some possible effect no matter what level is present. There is no level that may not produce an effect.

(60) "No observed adverse effect level" or "NOAEL" is the highest tested dose or concentration of a substance that resulted in no observed adverse effect in exposed test organisms where higher doses or concentrations resulted in an adverse effect.

(61) "No observed effect concentration" or "NOEC" is the highest concentration of toxicant to which organisms are exposed in a full life cycle or partial life cycle (short term) test, that causes no observable adverse effects on the test organisms, that is, the highest concentration of toxicant in which the values for the observed responses are not statistically significantly different from the controls.

(62) "Occur at the site" includes the species, genera, families, orders, classes, and phyla that:

(A) are usually present at the site;

(B) are present at the site only seasonally due to migration;

(C) are present intermittently because they periodically return to or extend their ranges into the site;

(D) were present at the site in the past, are not currently present at the site due to degraded conditions, and are expected to return to the site when conditions improve; or

(E) are present in nearby bodies of water, are not currently present at the site due to degraded conditions, and are expected to be present at the site when conditions improve.

The taxa that occur at the site cannot be determined merely by sampling downstream and upstream of the site at one (1) point in time. The term does not include taxa that were once present at the site but cannot exist at the site now due to permanent physical alteration of the habitat at the site, for example, alterations resulting from dams.

(63) "Octanol-water partition coefficient" or "K_OW" means the ratio of the concentration of a substance in the n-octanol phase to its concentration in the aqueous phase in an equilibrated two-phase octanol-water system. For log K_OW, the log of the octanol-water partition coefficient is a base ten (10) logarithm.

(64) "Open waters of Lake Michigan" means all of the waters within Lake Michigan lakeward from a line drawn across the mouth of tributaries to the lake, including all waters enclosed by constructed breakwaters. For the Indiana Harbor Ship Canal, the boundary of the open waters of Lake Michigan is delineated by a line drawn across the mouth of the harbor from the East Breakwater Light (1995 United States Coast Guard Light List No. 19675) to the northernmost point of the LTV Steel property along the west side of the harbor.

(65) "Outstanding national resource water" means a water designated as such by the general assembly after recommendations by the water pollution control board and the environmental quality service council under IC 13-18-3-2(o) and IC 13-18-3-2(p). The designation must describe the quality of the outstanding national resource water to serve as the benchmark of the water quality that shall be maintained and protected. Waters that may be considered for designation as outstanding national resource waters include waterbodies that are recognized as:

(A) important because of protection through official action, such as:

(i) federal or state law;

(ii) presidential or secretarial action;

(iii) international treaty; or

(iv) interstate compact;

(B) having exceptional recreational significance;

(C) having exceptional ecological significance;

(D) having other special environmental, recreational, or ecological attributes; or

(E) waters with respect to which designation as an outstanding national resource water is reasonably necessary for protection of other waterbodies designated as outstanding national resource waters.

(66) "Outstanding state resource water" means any water designated as such by the water pollution control board regardless of when the designation occurred or occurs. Waters that may be considered for designation as outstanding state resource waters include waterbodies that have unique or special ecological, recreational, or aesthetic significance.

(67) "Point source" has the meaning set forth in 327 IAC 5-1.5-40.

(68) "Policy" means a statement of administrative practice or decision making guidelines to be followed or implemented to the maximum extent feasible with respect to an identified problematic situation but to be less than strictly enforceable in contrast to a standard or rule of law.

(69) "Public water supply" means a source of water for a public water system.

(70) "Public water system" has the meaning set forth in 42 U.S.C. 300f.

(71) "Quantitative structure activity relationship" or "QSAR" or "structure activity relationship" or "SAR" refers to a mathematical relationship between a property (activity) of a chemical and a number of descriptors of the chemical. These descriptors are chemical or physical characteristics obtained experimentally or predicted from the structure of the chemical.

(72) "Relative source contribution" or "RSC" means the factor (percentage) used in calculating an HNV or HNC to account for all sources of exposure to a contaminant. The RSC reflects the percent of total exposure that may be attributed to surface water through water intake and fish consumption.

(73) "Risk" means the probability that a substance, when released to the environment, will cause an adverse effect in exposed humans or other living organisms.

(74) "Risk assessment" means the analytical process used to determine the level of risk.

(75) "Risk associated dose" or "RAD" refers to a dose of a known or presumed carcinogenic substance in milligrams per kilogram per day, which, over a lifetime of exposure, is estimated to be associated with a plausible upper bound incremental cancer risk equal to one (1) in one hundred thousand (100,000).

(76) "Secondary continuous concentration" or "SCC" means an estimate of the highest concentration of a material in the water column to which an aquatic community can be exposed indefinitely without resulting in an unacceptable effect. The SCC differs from the CCC in that fewer data are required to calculate the SCC than the CCC.

(77) "Secondary maximum concentration" or "SMC" means an estimate of the highest concentration of a material in the water column to which an aquatic community can be exposed briefly without resulting in an unacceptable effect. The SMC differs from the CMC in that fewer data are required to calculate the SMC than the CMC.

(78) "Slope factor", also known as "q₁*", means the incremental rate of cancer development calculated through use of a linearized multistage model or other appropriate model. Slope factor is expressed in milligrams per kilogram per day of exposure to the chemical in question.

(79) "Species mean acute value" or "SMAV" means the geometric mean of the results of all acceptable flow-through acute toxicity tests (for which the concentrations of the test material were measured) with the most sensitive tested life stage of the species. For a species for which no such result is available for the most sensitive tested life stage, the SMAV is the geometric mean of the results of all acceptable acute toxicity tests with the most sensitive tested life stage.

(80) "Species mean chronic value" or "SMCV" means the geometric mean of the results of all acceptable life-cycle and partial life-cycle toxicity tests with the species; for a species of fish for which no such result is available, the SMCV is the geometric mean of all acceptable early life-stage tests.

(81) "Steady-state" means an equilibrium condition has been achieved in the body burden of a substance in an organism. Steady-state is assumed when the rate of loss of a substance matches its rate of uptake.

(82) "Stream design flow" means the stream flow that represents critical conditions, upstream from the source, for protection of aquatic life, human health, or wildlife.

(83) "Subchronic effect" means an adverse effect, measured by assessing an acceptable endpoint, resulting from continual exposure for a period of time less than that deemed necessary for a chronic test.

(84) "Surface waters of the state" or "surface water" has the meaning set forth in IC 13-11-2-265 except that the term does not include underground waters with the exception of the following:

(A) The underground portion of the Lost River and its underground tributaries.

(B) Any other underground stream that supports fish or other higher aquatic life forms and its underground tributaries.

(85) "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.

(86) "Tier I criteria" means numeric values derived by use of the Tier I procedures in sections 11 and 13 through 16 of this rule that either have been adopted as numeric criteria into a water quality standard or are used to implement narrative water quality criteria.

(87) "Tier II values" means numeric values derived by use of the Tier II procedures in sections 12 through 16 of this rule that are used to implement narrative water quality criteria.

(88) "Toxic substances" means substances that are or may become harmful to:

(A) aquatic life;

(B) humans;

(C) other animals;

(D) plants; or

(E) food chains;

when present in sufficient concentrations or combinations. Toxic substances include, but are not limited to, those pollutants identified as toxic under Section 307(a)(1) of the Clean Water Act.

(89) "Tributaries of the Great Lakes system" means all waters of the Great Lakes system that are not open waters of Lake Michigan.

(90) "Trophic level" means a functional classification of taxa within a community that is based on feeding relationships, for example, aquatic green plants comprise the first trophic level and herbivores comprise the second.

(91) "Uncertainty factor" or "UF" means one (1) of several numeric factors used in operationally deriving criteria from experimental data to account for the quality or quantity of the available data.

(92) "Uptake" means acquisition of a substance from the environment by an organism as a result of any active or passive process.

(93) "Variance" means a deviation from a water quality standard.

(94) "Water-effect ratio" or "WER" means the ratio that is computed as a specific pollutant’s acute or chronic toxicity endpoint measured in water from the site covered by the criterion, divided by the respective acute or chronic toxicity endpoint in laboratory dilution water.

(95) "Waters of the state" has the meaning set forth in IC 13-11-2-265.

(96) "Water use designations" means a use of the waters of the state as established by this rule, including, but not limited to, the following:

(A) Industrial water supply.

(B) Agricultural use.

(C) Public water supply.

(D) Full body contact.

(E) Aquatic life.

(F) Limited use.

(97) "Well-balanced aquatic community" means an aquatic community that:

(A) is diverse in species composition;

(B) contains several different trophic levels; and

(C) is not composed mainly of pollution tolerant species.

(98) "Wildlife criterion" or "WC" means the criterion used to denote the number derived from data meeting the Tier I minimum database requirements and will be protective of the two (2) classes of wildlife. The term is synonymous with GLWC, and the two (2) are used interchangeably.

(99) "Wildlife value" or "WV" means:

(A) a value used to denote each representative species that results from using the equation presented in section 15 of this rule;

(B) the value obtained from averaging species values within a class; or

(C) any value derived from application of the site-specific procedure provided in section 16 of this rule.

The WVs calculated for the representative species are used to calculate taxonomic class-specific WVs. The WV is the concentration of a substance that, if not exceeded, should better protect the taxon in question.

(100) "Zone of initial dilution" or "ZID" means the area of the receiving water directly after the end of the pipe where an instantaneous volume of water gives up to a one-to-one (1:1) dilution of the discharge.

(Water Pollution Control Division; 327 IAC 2-1.5-2; filed Jan 14, 1997, 12:00 p.m.: 20 IR 1363; errata filed Aug 11, 1997, 4:15 p.m.: 20 IR 3376; filed Feb 14, 2005, 10:05 a.m.: 28 IR 2068)