Section 327IAC2-1-9. Definitions

   In addition to the definitions contained in IC 13-11-2, the following definitions apply throughout this title:

(1) "Acceptable daily intake" or "ADI" represents the maximum amount of a substance that if ingested daily for a lifetime results in no adverse effects to humans.

(2) "Acute aquatic criterion" or "AAC" means the highest concentration of chemical that if met instream will protect the aquatic life present from mortality or other irreversible effects due to short term exposure. The AAC is equal to one-half (1/2) the final acute value (FAV).

(3) "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.

(4) "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.

(5) "Bioaccumulative chemical of concern" or "BCC" refers to the following substances:

Table 9-1
Bioaccumulative Chemicals of Concern
CAS Number	Substance
309002	Aldrin
57749	Chlordane
72548	4,4'-DDD; p,p'-DDD; 4,4'-TDE; p,p'-TDE
72559	4,4'-DDE; p,p'-DDE
50293	4,4'-DDT; p,p'-DDT
60571	Dieldrin
72208	Endrin
76448	Heptachlor
118741	Hexachlorobenzene
87683	Hexachlorobutadiene; hexachloro-1,3-butadiene
608731	Hexachlorocyclohexanes; BHCs
319846	alpha-Hexachlorocyclohexane; alpha-BHC
319857	beta-Hexachlorocyclohexane; beta-BHC
319868	delta-Hexachlorocyclohexane; delta-BHC
58899	Lindane; gamma-Hexachlorocyclohexane; gamma-BHC
7439976	Mercury
2385855	Mirex
29082744	Octachlorostyrene
1336363	PCBs; polychlorinated biphenyls
608935	Pentachlorobenzene
39801144	Photomirex
1746016	2,3,7,8-TCDD; dioxin
634662	1,2,3,4-Tetrachlorobenzene
95943	1,2,4,5-Tetrachlorobenzene
8001352	Toxaphene

(6) "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.

(7) "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.

(8) "Carcinogen" means a chemical that causes an increased incidence of benign or malignant neoplasms, or a substantial decrease in the latency period between exposure and onset of neoplasms through oral or dermal exposure, or through inhalation exposure when the cancer occurs at nonrespiratory sites in at least one (1) mammalian species or man through epidemiological studies or clinical studies, or both.

(9) "Chronic aquatic criterion" or "CAC" means the highest concentration of chemical that if met instream will protect the aquatic life present from toxic effects due to long term exposure, for example, adverse effects on growth and reproduction.

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

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

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

(13) "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.

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

(15) "Discharge-induced mixing" or "DIM" means mixing initiated by the use of submerged, high rate diffuser outfall structures (or the functional equivalent) that provide turbulent initial mixing and will minimize organism exposure time.

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

(17) "Endangered or threatened species" includes those species that are listed as endangered or threatened under Section 4 of the Endangered Species Act (ESA) except as specifically provided for in 327 IAC 2-1.3.

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

(19) "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 genus mean acute values (GMAVs); or

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

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

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

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

(23) "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.

(24) "Great Lakes system" has the meaning set forth in 327 IAC 2-1.5-2(44).

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

(26) "Human life cycle safe concentration" or "HLSC" is the highest concentration of a chemical to which a human is exposed continuously for a lifetime and that results in no observable adverse effects to a human and its progeny.

(27) "Indigenous" means, generally, an organism native to and growing and reproducing in a particular region. For purposes of this rule, the term also includes historically nonnative species introduced by the Indiana department of natural resources as part of a program of wildlife management whether such species reproduce or not.

(28) "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.

(29) "LD₅₀" means the median lethal dose of a chemical, which is the amount of a test material per body weight that, when administered, results in fifty percent (50%) mortality to the organisms during a specified time period.

(30) "Life cycle safe concentration" means the highest concentration of a chemical to which an organism is exposed continuously for a lifetime and that results in no observable adverse effects to the organism and its progeny.

(31) "Lowest observable 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.

(32) "MATC" means the maximum acceptable toxicant 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 specified adverse effect. An upper chronic limit is the lowest tested concentration that did cause the occurrence of a specified adverse effect and above which all tested concentrations caused such an occurrence.

(33) "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.

(34) "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.

(35) "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.

(36) "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.

(37) "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.

(38) "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.

(39) "Outstanding national resource water" means a water designated as such by the general assembly after recommendations by the environmental rules 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.

(40) "Outstanding state resource water" means any water designated as such by the environmental rules 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.

(41) "Persistent substance" means a chemical that is long-lived in soil, aquatic environments, and animal and plant tissues and is not readily broken down by biological or physiochemical processes.

(42) "Point source" means the following:

(A) Any discernible, confined, and discrete conveyance, including, but not limited to, any of the following from which pollutants are or may be discharged:

(i) Pipe.

(ii) Ditch.

(iii) Channel.

(iv) Tunnel.

(v) Conduit.

(vi) Well.

(vii) Discrete fissure.

(viii) Container.

(ix) Rolling stock.

(x) Concentrated animal feeding operation.

(xi) Landfill leachate collection system.

(xii) Vessel.

(xiii) Other floating craft.

(B) The term does not include return flows from irrigated agriculture or agricultural storm run-off. See 327 IAC 5-2-4(a)(4) for other exclusions.

(43) "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.

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

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

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

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

(48) "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.

(49) "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.

(50) "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.

(51) "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.

(52) "Terrestrial life cycle safe concentration" or "TLSC" is the highest concentration of chemical to which wildlife is exposed continuously for a lifetime and that results in no observable adverse effects to wildlife and its progeny.

(53) "Threshold mechanism" means a process that results in some effect if a certain level is exceeded, but that produces no effect below that level.

(54) "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.

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

(56) "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.

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

(58) "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.

(59) "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.

(60) "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 2-1-9; filed Sep 24, 1987, 3:00 p.m.: 11 IR 584; filed Feb 1, 1990, 4:30 p.m.: 13 IR 1041; errata filed Jul 6, 1990, 5:00 p.m.: 13 IR 2004; filed Jan 14, 1997, 12:00 p.m.: 20 IR 1360; errata filed Aug 11, 1997, 4:15 p.m.: 20 IR 3376; filed Feb 14, 2005, 10:05 a.m.: 28 IR 2060; filed Nov 10, 2014, 1:51 p.m.: 20141210-IR-327130290FRA)