NR 105.06(5)(b)1.
1. If the acute toxicity of a substance is related to any water quality parameter, the acute-chronic ratio shall be based on acute and chronic toxicity data obtained from organisms exposed to test water with similar, if not identical, values of those water quality parameters. Preference under this paragraph shall be given to data from acute and chronic tests done by the same author or reference in order to increase the likelihood of comparable test conditions.
NR 105.06(5)(b)2.
2. If the acute and chronic toxicity data indicate that the acute-chronic ratio varies with changes in the values of the water quality parameters, the acute-chronic ratio used at specified values of the water quality parameters shall be based on the ratios at values closest to that specified.
NR 105.06(5)(b)3.
3. If the acute toxicity of a substance is unrelated to water quality parameters, the acute-chronic ratio may be derived from any acute and chronic test on a species regardless of the similarity in values of those parameters. Preference under this paragraph shall be given to data from acute and chronic tests done by the same author or reference to increase the likelihood of comparable test conditions.
NR 105.06(5)(c)
(c) A final chronic value shall be calculated for a substance under this subsection only if at least one acute-chronic ratio is available for at least one species of aquatic animal in at least 3 different families, provided that of the 3 species, one is a fish, one is an invertebrate, and the third is a relatively sensitive freshwater species on an acute toxicity basis. The other 2 may be saltwater species.
NR 105.06(5)(d)
(d) The geometric mean acute-chronic ratio is calculated for each species using the available acute-chronic ratios for that species. That mean ratio shall be called the species mean acute-chronic ratio (SMACR).
NR 105.06(5)(e)
(e) For a given substance, if the SMACR appears to increase or decrease as the species or genus mean acute values (SMAVs or GMAVs) calculated for that substance using the procedure described in s.
NR 105.05 increase, the final acute-chronic ratio (FACR) shall be equal to the geometric mean of the SMACRs for species with SMAVs closest to the final acute value.
NR 105.06(5)(f)
(f) For a given substance, if no trend is apparent regarding changes in SMACRs and GMAVs, the FACR shall be equal to the geometric mean of all SMACRs available for that substance.
NR 105.06(5)(g)
(g) For a given substance, the final chronic value (FCV) shall be equal to the final acute value (FAV) divided by the final acute-chronic ratio (FACR). The chronic toxicity criterion shall be equal to the lower of the FCV and the final plant value as calculated using the procedure in s.
NR 105.11, if available.
NR 105.06(5)(h)
(h) Chronic toxicity criteria for the fish and aquatic life subcategories listed in s.
NR 102.04 (3) that are calculated using acute-chronic ratios are listed in Table 5 for substances with acute toxicity unrelated to water quality parameters and in Table 6 for substances with acute toxicity related to water quality parameters. Equations listed in Table 6 are applicable over the range of water quality parameters as contained in Table 4A. Table 2A should be used where no range is listed in Table 4A.
NR 105.06(6)
(6)
Secondary chronic values. If all 8 minimum data requirements for calculating FCVs in sub.
(1) (a) are not met for a substance, secondary chronic values (SCVs) shall be calculated for that substance using the procedure in this subsection.
NR 105.06(6)(a)
(a) If any one of the combinations of information in subds.
1. to
3. is available, a SCV may be calculated. To calculate a SCV for a substance, the acute value from subds.
1. to
3. is divided by the applicable acute-chronic ratio in the same subdivision.
NR 105.06(6)(a)1.
1. Calculate a FAV using the procedure in s.
NR 105.05 (2) and divide it by a secondary acute-chronic ratio (SACR) using the procedure in sub.
(7).
NR 105.06(6)(b)
(b) If appropriate, the SCV shall be made a function of a water quality characteristic in a manner similar to that described in sub.
(4) (a).
NR 105.06(6)(c)
(c) If, for a commercially, recreationally or ecologically important species, the SMCV is lower than the calculated SCV, that SMCV shall be used as the SCV instead of the calculated SCV.
NR 105.06(6)(d)
(d) If there is an FPV available using the procedure in s.
NR 105.11 which is lower than the calculated SCV, that FPV shall be used as the SCV instead of the calculated SCV.
NR 105.06(7)(a)
(a) If a FACR cannot be calculated using the procedure in sub.
(5) because SMACRs are not available for a fish, an invertebrate or an acutely sensitive freshwater species, a secondary acute-chronic ratio (SACR) may be calculated using the procedure in this subsection.
NR 105.06(7)(b)
(b) The SACR shall be equal to the geometric mean of 3 acute-chronic ratios. Those ratios consist of the SMACRs available for the species in sub.
(5) (c). When SMACRs are not available for the species in par.
(a), the default acute-chronic ratio to be used is 18. Use of a SACR will result in the calculation of a secondary chronic value.
NR 105.06(8)
(8)
Chronic toxicity criteria expressed in the dissolved form. Chronic water quality criteria may be expressed as a dissolved concentration. The conversion of a chronic water quality criterion expressed as a total recoverable concentration to a chronic water quality criterion expressed as a dissolved concentration, the portion of the substance which will pass through a 0.45 um filter, shall be done using the equations in pars.
(a) and
(b). Substances which may have criteria expressed as a dissolved concentration are listed in par.
(a) with corresponding conversion factors.
NR 105.06(8)(a)
(a) The conversion of the water quality criterion expressed as total recoverable (WQC
Total R.) to the water quality criterion expressed as dissolved (WQC
D) shall be performed as follows:
WQCD = (CF)(WQCTotal R.)
Where: WQCTotal R. = Criteria from NR 105, Table 5 or 6.
CF = Conversion factor for total recover-
able to dissolved.
Conversion factors are as follows:
Arsenic 1.000
Cadmium 0.850
Chromium (III) 0.860
Chromium (VI) 0.962
Copper 0.960
Lead 0.792
Mercury 0.85
Nickel 0.997
Selenium 0.922
Zinc 0.986
NR 105.06(8)(b)
(b) The translation of the WQC
D into the water quality criterion which accounts for site-specific conditions (WQC
TRAN) shall be performed as follows:
WQCTRAN = (Translator)(WQCD)
Where: Translator (unitless) = ((MP)(TSS) + MD)/MD
MP = Particle-bound concentration of the pollutant (ug/g) in receiving water.
MD = Dissolved concentration of the pollutant in receiving water (ug/L).
TSS = Total Suspended Solids (g/L) concentration in receiving water.
NR 105.06 Note
Note:
*Criterion listed is applicable to the “total recoverable" form except for chlorine which is applicable to the “total residual" form.
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See PDF for table 
NR 105.06 History
History: Cr.
Register, February, 1989, No. 398, eff. 3-1-89; am. (5) (f) and Tables 2, 2a, 4, 4a and 6,
Register, July, 1995, No. 475, eff. 8-1-95; am. (1) (a) 1., 2., 4., and 5., (1) (b), (3) (intro.), (a) to (g), (4) (a) 1., 7. to 13., (5) (c), renum. (1) (a) 6. to be (1) (a) 10., (3) (h) to be (3) (i) and am. (1) (a) 10, (4) (a) 6. to be (4) (a) 6. a., (4) (b) to be (4) (c), (5) (e) to (i) to be (5) (d) to (h) and am. (5) (e) to (g), cr. (3) (h), (4) (a) 6. b., (4) (b), (5) (b) 3., (6) to (8), r. and recr., Tables 1 to 2a, 3 to 6, r. (5) (d)
; am. Tables 1 and 5,
Register, January, 2000, No. 529, eff. 2-1-00
; CR 03-050: am. Tables 2 and 6, cr. Tables 2C and 4B
Register February 2004 No. 578, eff. 3-1-04;
CR 07-110: am Tables 2, 2A, 5 and 6
Register November 2008 No. 635, eff. 12-1-08;
CR 09-123: am. (5) (h), (8) (a), Tables 4B and 5
Register July 2010 No. 655, eff. 8-1-10.
NR 105.07(1)(1)
The wildlife criterion is the concentration of a substance which if not exceeded protects Wisconsin's wildlife from adverse effects resulting from ingestion of surface waters of the state and from ingestion of aquatic organisms taken from surface waters of the state.
NR 105.07(1)(a)
(a) For any substance not shown in Table 7, the wildlife criterion (WC) is the lower of the available mammalian or avian wildlife values (WVs) calculated pursuant to sub.
(2). A wildlife criterion protective of Wisconsin's reptile fauna may be calculated pursuant to sub.
(2) whenever data specific to reptiles are available.
NR 105.07(2)(a)(a) Mammalian and avian wildlife values shall be calculated as follows using information available from scientifically acceptable studies of animal species exposed repeatedly to the substance via oral routes including gavage:
WV = NOAEL x WtA x SSF
NR 105.07(2)(b)
(b) The selection of the species sensitivity factor (SSF) shall be based on the available toxicological data base and available physicochemical and toxicokinetic properties of the substance and the amount and quality of available data.
NR 105.07(2)(c)
(c) The bald eagle, kingfisher, herring gull, mink and otter are representative of avian and mammalian species to be protected by wildlife criteria. A NOAEL specific to each taxonomic class is used to calculate WVs for each of the 5 representative species. The avian WV is the geometric mean of the WVs calculated for the 3 representative avian species. The mammalian WV is the geometric mean of the WVs calculated for the 2 representative mammalian species.
NR 105.07(2)(d)
(d) In those cases in which more than one NOAEL is available, the following shall apply:
NR 105.07(2)(d)1.
1. If more than one NOAEL is available within a taxonomic class, based on the same endpoint of toxicity, the NOAEL from the most sensitive species shall be used.
NR 105.07(2)(d)2.
2. If more than one NOAEL is available for a given species, based on the same enpoint of toxicity, the NOAEL for that species shall be calculated using the geometric mean of those NOAELs.
NR 105.07(2)(e)
(e) Because wildlife consume fish from both trophic levels 3 and 4, baseline BAFs shall be available for both trophic levels 3 and 4 to calculate either a criterion or secondary value for a chemical. When appropriate, ingestion through consumption of invertebrates, plants, mammals and birds in the diet of wildlife species to be protected shall be included.
NR 105.07(3)
(3) In those cases in which a no observed adverse effect level (NOAEL) is available from studies of mammalian or avian species exposed repeatedly to the substance via oral routes including gavage, but is available in units other than mg/kg-d as specified in sub.
(2), the following procedures shall be used to express the NOAEL prior to calculating the wildlife value:
NR 105.07(3)(a)
(a) If the NOAEL is given in milligrams of toxicant per liter of water consumed (mg/L), the NOAEL shall be multiplied by the daily average volume of water consumed by the test animals in liters per day (L/d) and divided by the average weight of the test animals in kilograms (kg).
NR 105.07(3)(b)
(b) If the NOAEL is given in milligrams of toxicant per kilogram of food consumed (mg/kg), the NOAEL shall be multiplied by the average amount of food in kilograms consumed daily by the test animals (kg/d) and divided by the average weight of the test animals in kilograms (kg).
NR 105.07(4)
(4) In those cases in which a NOAEL is unavailable and a lowest observed adverse effect level (LOAEL) is available from studies of animal species exposed repeatedly to the substance via oral routes including gavage, the LOAEL may be substituted with proper adjustment to estimate the NOAEL. An uncertainty factor of between one and 10 may be applied to the LOAEL, depending on the sensitivity of the adverse effect, to reduce the LOAEL into the range of a NOAEL. If the LOAEL is available in units other than mg/kg-d, the LOAEL shall be expressed in the same manner as that specified for the NOAEL in sub.
(3).
NR 105.07(5)
(5) In instances where a NOAEL is based on subchronic data, an uncertainty factor may be applied to extrapolate from subchronic to chronic levels. The value of the uncertainty factor may not be less than 0.1 and may not exceed 1.0. This factor is to be used when assessing highly bioaccumulative substances where toxicokinetic considerations suggest that a bioassay of limited length underestimates chronic effects.
NR 105.07(6)
(6) If drinking or feeding rates are not available for representative species, drinking (W) and feeding rates (F
TLi) shall be calculated for representative mammalian or avian species by using the allometric equations given in pars.
(a) and
(b).
NR 105.07 Note
Note: Criteria to protect domestic animals will be considered on an as needed basis using a model that accounts for domestic animal exposure through drinking water. Because domestic animals do not regularly consume aquatic organisms, the wildlife exposure model is not appropriate.
NR 105.07 History
History: Cr.
Register, February, 1989, No. 398, eff. 3-1-89; am. table 7,
Register, July, 1991, No. 427, eff. 8-1-91; am. (1), (2) (a), (b), (3) (intro.), (6) (intro.), r. and recr. (2) (c), (5), cr. (2) (d), (e), r. (6) (a), renum. (6) (b) and (c) to be (6) (a) and (b) and am.,
Register, August, 1997, No. 500, eff. 9-1-97.
NR 105.08
NR 105.08 Human threshold criteria. NR 105.08(1)(1)
The human threshold criterion (HTC) is the maximum concentration of a substance established to protect humans from adverse effects resulting from contact with or ingestion of surface waters of the state and from ingestion of aquatic organisms taken from surface waters of the state. Human threshold criteria are derived for those toxic substances for which a threshold dosage or concentration can be estimated below which no adverse effect or response is likely to occur.
NR 105.08(2)
(2) For noncarcinogenic components of mixtures in effluents, interactions among substances may be additive, antagonistic or synergistic and may be accounted for by a model that is supported by credible scientific evidence. The risks are assumed to be additive when substances are members of the same structural class and cause potential adverse effects via the same mechanism of action, influencing the same kind of endpoint, and shall be accounted for by a model that is supported by credible scientific evidence.
NR 105.08(3)
(3) Human threshold criteria are listed in Table 8. Criteria for the same substance may be different depending on the surface water classification, due to the lipid value of representative fish, a component of the BAF, and whether or not the water may be a source of drinking water. Further application of these criteria to protect drinking water and downstream uses in the Great Lakes system shall be according to s.
NR 106.06 (1) NR 105.08(4)
(4) To derive human threshold criteria for substances not included in Table 8 the following methods shall be used:
NR 105.08(4)(b)
(b) For surface waters classified as public water supplies, if the human threshold criterion for a toxic substance as calculated in par.
(a) exceeds the maximum contaminant level (MCL) for that substance as specified in ch.
NR 809 or
the July 8, 1987 Federal Register (52 FR 25690), the MCL shall be used as the human threshold criterion.
NR 105.08(5)
(5) The acceptable daily exposure (ADE) referenced in sub.
(4) represents the maximum amount of a substance which if ingested daily for a lifetime results in no adverse effects to humans. Paragraphs
(a) to
(c) list methods for determining the acceptable daily exposure.
NR 105.08(5)(a)
(a) The department shall review available references for acceptable daily exposure or equivalent values, such as a reference dose (RfD) as used by the U.S. environmental protection agency, and for human or animal toxicological data from which an acceptable daily exposure can be derived. Suitable references for review include, but are not limited to, those presented in s.
NR 105.04 (5).
NR 105.08(5)(b)
(b) When human or animal toxicological data are available, the department may derive an acceptable daily exposure by using as guidance procedures presented by the U.S. environmental protection agency in “Water Quality Criteria Documents; Availability" (45 FR 79318, November 28, 1986). Additional guidance for deriving acceptable daily exposures from toxicological data are given in subds.
1. to
4. Alternate procedures may be used if supported by credible scientific evidence.
NR 105.08(5)(b)1.
1. No observable adverse effect levels (NOAELs) and lowest observable adverse effect levels (LOAELs) from studies of humans or mammalian test species shall be divided by an uncertainty factor to derive an acceptable daily exposure. Uncertainty factors reflect uncertainties in predicting acceptable exposure levels for the general human population based upon experimental animal data or limited human data. Factors to be considered when selecting an uncertainty factor include, but are not limited to, interspecies and individual variations in response and susceptibility to a toxicant, and the quality and quantity of the available data. The following guidelines shall be considered when selecting an uncertainty factor:
NR 105.08(5)(b)1.a.
a. Use an uncertainty factor of 10 when extrapolating from valid experimental results from studies on prolonged ingestion by humans. This 10-fold factor protects sensitive members of the human population.
NR 105.08(5)(b)1.b.
b. Use an uncertainty factor of 100 when extrapolating from valid results of long-term feeding studies on experimental animals with results of studies of human ingestion not available or insufficient (e.g., acute exposure only). This represents an additional 10-fold uncertainty factor in extrapolating data from the average animal to the average human.
NR 105.08(5)(b)1.c.
c. Use an uncertainty factor of 1000 when extrapolating from less than chronic results on experimental animals with no useful long-term or acute human data. This represents an additional 10-fold uncertainty factor in extrapolating from less than chronic to chronic exposures.
NR 105.08(5)(b)1.d.
d. Use an additional uncertainty factor of between 1 and 10 depending on the severity of the adverse effect when deriving an acceptable daily exposure from a lowest observable adverse effect level (LOAEL). This uncertainty factor reduces the LOAEL into the range of a no observable adverse effect level (NOAEL).
NR 105.08(5)(b)1.e.
e. Use an additional uncertainty factor of 10 when deriving an acceptable daily exposure for a substance which the U.S. environmental protection agency classifies as a “group C" carcinogen, but which is not defined as a carcinogen in s.
NR 105.03 (13).
NR 105.08(5)(b)2.
2. Results from studies of humans or mammalian test species used to derive acceptable daily exposures shall have units of milligrams of toxicant per kilogram of body weight per day (mg/kg-d). When converting study results to the required units, a water consumption of 2 liters per day (L/d) and a body weight of 70 kilograms (kg) is assumed for humans. The following examples and procedures illustrate the conversion of units:
