Rule 57.
(3) Levels of toxic substances in the surface waters of the state shall not exceed the wildlife values specified in table 4 or, in the absence of such values, the wildlife values derived according to the following process, unless site-specific modifications have been developed pursuant to subdivision (n) of this subrule: (a) Tier I wildlife values for the BCCs listed in table 5, with the exception of the wildlife values listed in table 4, shall be calculated using the following equation: Click here To View Image
Where:
WV = wildlife value in milligrams of substance per liter (mg/L).
TD = test dose (TD) in milligrams of substance per kilograms per day (mg/kg/d) for the test species. This shall be either a NOAEL or a LOAEL.
UFA = uncertainty factor (UF) for extrapolating toxicity data across species (unitless).
A species-specific UF shall be selected and applied to each representative species, consistent with the equation.
UFS = UF for extrapolating from subchronic to chronic exposures (unitless).
UFL = UF for LOAEL to NOAEL extrapolations (unitless).
Wt = average weight in kilograms (kg) for the representative species.
W = average daily volume of water consumed in liters per day (L/d) by the representative species.
FTLi = average daily amount of food consumed from trophic level i in kilograms per day (kg/d) by the representative species.
BAF TLi[GREATER THAN EQUAL TO] bioaccumulation factor (BAF) for wildlife food in trophic level i in liters per kilogram (L/kg), developed using the BAF methodology in subrule (5) of this rule. For consumption of piscivorous birds by other birds, for example herring gulls by eagles, the BAF is derived by multiplying the trophic level 3 BAF for fish by a biomagnification factor to account for the biomagnification from fish to the consumed birds.
(b) Piscivorous species are identified as the focus of concern for wildlife values. Three avian species - eagle, kingfisher, and herring gull - and 2 mammalian species -mink and otter - are used as representative species for protection. The TD obtained from toxicity data for each taxonomic class is used to calculate WVs for each of the 5 representative species.(c) 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. The lower of the mammalian and avian WVs shall be the final WV.(d) A TD value is required for WV calculation. To derive a WV, the data set shall be sufficient to generate a subchronic or chronic dose-response curve for any given substance for both mammalian and avian species using acceptable wildlife endpoints. In reviewing the toxicity data available that meet the minimum data requirements for each taxonomic class, data from peer-reviewed field studies of wildlife species take precedence over other types of studies where the studies are of adequate quality. An acceptable field study shall be of subchronic or chronic duration, provide a defensible, chemical-specific dose-response curve in which cause and effect are clearly established, and assess acceptable wildlife endpoints. When acceptable wildlife field studies are not available or are determined to be of inadequate quality, the needed toxicity information may come from peer-reviewed laboratory studies. When laboratory studies are used, preference shall be given to laboratory studies with wildlife species over traditional laboratory animals to reduce uncertainties in making interspecies extrapolations. All available laboratory data and field studies shall be reviewed to corroborate the final WV, to assess the reasonableness of the toxicity value used, and to assess the appropriateness of any UFs that are applied. All of the following requirements apply when evaluating the studies from which a TD is derived: (i) The mammalian data shall come from at least 1 well-conducted study of 90 days or more that is designed to observe acceptable wildlife endpoints.(ii) The avian data shall come from at least 1 well-conducted study of 70 days or more that is designed to observe acceptable wildlife endpoints.(iii) In reviewing the studies from which a TD is derived for use in calculating a WV, studies involving exposure routes other than oral may be considered only when an equivalent oral daily dose can be estimated and technically justified. The WV calculations are based on an oral route of exposure.(iv) In assessing the studies that meet the minimum data requirements, preference should be given to studies that assess effects on developmental or reproductive endpoints because, in general, these are more important endpoints in ensuring that a population's productivity is maintained.(e) In selecting data to be used in the derivation of WVs, the evaluation of acceptable endpoints will be the primary selection criterion. All data that are not part of the selected subset may be used to assess the reasonableness of the toxicity value and the appropriateness of the UFs. In addition, the following provisions shall apply: (i) If more than 1 TD value based on different endpoints of toxicity is available within a taxonomic class, then that TD, which is likely to reflect best potential impacts to wildlife populations through resultant changes in mortality or fecundity rates, shall be used for the calculation of WVs.(ii) If more than 1 TD based on the same endpoint toxicity is available within a taxonomic class, then the TD from the most sensitive species shall be used.(iii) If more than 1 TD based on the same endpoint of toxicity is available for a given species, then the TD for that species shall be calculated using the geometric mean of the TDs for the same endpoint of toxicity.(f) If a TD is available in units other than milligrams of substance per kilograms per day (mg/kg/d), then the following procedures shall be used to convert the TD to the appropriate units before calculating a WV: (i) If the TD is given in milligrams of toxicant per liter of water consumed by the test animals (mg/L), then the TD 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).(ii) If the TD is given in milligrams of toxicant per kilogram of food consumed by the test animals (mg/kg), then the TD 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).(g) When drinking and feeding rates and body weight are needed to express the TD in milligrams of substance per kilograms per day (mg/kg/d), they are obtained from the study from which the TD was derived. If not already determined, body weight and drinking and feeding rates are to be converted to a wet weight basis. If the study does not provide the needed values, then the values shall be determined as follows: (i) For studies done with domestic laboratory animals, use either the publication entitled "Registry of Toxic Effects, a Comprehensive Guide," 1993, United States Department of Health and Human Services, NIOSH Publication No. 97-119, or the publication entitled "Recommendations for and Documentation of Biological Values for use in Risk Assessment," United States EPA, 1988 NTIS-PB88-179874.(ii) If the references in paragraph (i) of this subdivision do not contain the information for the species used in a given study, then the following allometric equations shall be used: (A) For mammalian species, the general allometric equations are as follows:(1) F = 0.0687 x (Wt) 0.82 Where: F = feeding rate of mammalian species in kilograms per day (kg/d) dry weight.
Wt = average weight in kilograms (kg) of the test animals.
(2) W = 0.099 x (Wt) 0.90Where:
W = drinking rate of mammalian species in liters per day (L/d).
Wt = average weight in kilograms (kg) of the test animals.
(B) For avian species, the general allometric equations are as follows: (1) F = 0.0582 (Wt) 0.65Where:
F = feeding rate of avian species in kilograms per day (kg/d) dry weight. Wt = average weight in kilograms (kg) of the test animals.
(2) W = 0.059 x (Wt) 0.67Where:
W = drinking rate of avian species in liters per day (L/d).
Wt = average weight in kilograms (kg) of the test animals.
(h) If an NOAEL is unavailable as the TD and an LOAEL is available, then the LOAEL may be used to estimate the NOAEL. If used, the LOAEL shall be divided by a UF to estimate an NOAEL for use in deriving WVs. The value of the UF shall not be less than 1 and should not exceed 10, depending on the dose-response curve and any other available data, and is represented by UFL in the equation expressed in subdivision (a) of this subrule.(i) If only subchronic data are available, then the TD may be derived from subchronic data. In such cases, the TD shall be divided by a UF to extrapolate from subchronic to chronic levels. The value of the UF shall not be less than 1 and should not exceed 10, and is represented by UFS in the equation expressed in subdivision (a) of this subrule. This UF is to be used when assessing highly bioaccumulative substances where toxicokinetic considerations suggest that a bioassay of limited length underestimates chronic effects.(j) The selection of the UFA shall be based on the available toxicological data and on available data concerning the physicochemical, toxicokinetic, and toxicodynamic properties of the substance in question and the amount and quality of available data. This UFA is a UF that is intended to account for differences in toxicological sensitivity among species and both of the following provisions apply: (i) The UFA shall not be less than 1 and should not exceed 100 and shall be applied to each of the 5 representative species based on existing data and best professional judgment. The value of UFA may differ for each of the representative species.(ii) The UFA shall be used only for extrapolating toxicity data across species within a taxonomic class; however, an interclass extrapolation employing a UFA may be used for a given chemical if it can be supported by a validated biologically-based dose-response model or by an analysis of interclass toxicological data, considering acceptable endpoints, for a chemical analog that acts under the same mode of toxic action.(k) The body weights (Wt), feeding rates (FTLi), drinking rates (W), and trophic level dietary composition (as food ingestion rate and percent in diet) for each of the 5 representative species are presented in table 6. The methodology for development of bioaccumulation factors is presented in subrule (5) of this rule. Trophic level 3 and 4 BAFs are used to derive WVs because these are the trophic levels at which the representative species feed.(l) Determine, on the basis of all pertinent data available, whether the wildlife values derived are consistent with sound scientific evidence. If they are not, the values shall be adjusted to more appropriately reflect the weight of available scientific evidence.(m) The WVs shall be applied as a monthly average and compliance shall be based on the average of all daily measurements taken at a site within the same calendar month.(n) Wildlife values may be modified on a site-specific basis to be more or less stringent to reflect local environmental conditions. The modifications shall be derived by making appropriate site-specific adjustments to the methodology in this subrule. The following provisions shall apply:(i) Less stringent modifications shall be protective of designated uses of the surface waters of the state, shall be based on sound scientific rationale, shall not jeopardize the continued existence of endangered or threatened species listed or proposed under section 4 of the endangered species act or result in the destruction or adverse modification of the species critical habitat, and shall consider the mobility of both the prey organisms and wildlife populations in defining the site for which criteria are developed.(ii) More stringent modifications to protect endangered or threatened species listed or proposed under section 4 of the endangered species act may be accomplished by the use of an intraspecies uncertainty factor to account for protection of individuals within a wildlife population.(iii) Any site-specific modifications developed pursuant to this subdivision shall be approved by the department. (4) Levels of toxic substances in the surface waters of the state shall not exceed the human health values specified in tables 7 and 8 or, in the absence of such values, the values derived according to the following process, unless site-specific modifications have been developed pursuant to subdivision (h) of this subrule: (a) Human cancer values (HCVs) and human noncancer values (HNVs) shall be derived based on either a tier I or tier II classification. The 2 tiers are primarily distinguished by the amount of toxicity data available for deriving the concentration levels and the quantity and quality of data on bioaccumulation. The best available toxicity data on the adverse health effects of a chemical and the best data on bioaccumulation factors shall be used when developing human health values. The toxicity data shall include data from well-conducted epidemiological studies or animal studies, or both, that provide, for carcinogens, an adequate weight of evidence of potential human carcinogenicity and, for tier I values for noncarcinogens, a dose-response relationship involving critical effects biologically relevant to humans. These data shall be obtained from sources described in 40 C.F.R. §132, appendix C, item II, "Minimum Data Requirements" (1995), including the integrated risk information system (IRIS), the scientific literature, and other informational databases, studies, or reports that contain adverse health effects data of adequate quality for use in this procedure. Strong consideration shall be given to the most currently available guidance provided by IRIS in deriving values, supplemented with any recent data not incorporated into IRIS. Minimum data requirements to derive the human health values are as follows: (i) HCVs shall be derived if there is adequate evidence of potential human carcinogenic effects for a chemical. Carcinogens shall be classified, depending on the weight of evidence, as either human carcinogens, probable human carcinogens, or possible human carcinogens. To develop tier I and tier II human cancer values, the following minimum data sets are necessary:(A) Weight of evidence of potential human carcinogenic effects sufficient to derive a tier I HCV shall generally include human carcinogens and probable human carcinogens and can include, on a case-by-case basis, possible human carcinogens if studies have been well-conducted, although based on limited evidence, when compared to studies used in classifying human and probable human carcinogens. The decision to use data on a possible human carcinogen for deriving tier I values shall be a case-by-case determination. In determining whether to derive a tier I HCV, available information on mode of action, such as mutagenicity/genotoxicity (determinations of whether the chemical interacts directly with DNA), structure activity, and metabolism shall also be considered.(B) Weight of evidence of possible human carcinogenic effects sufficient to derive a tier II HCV shall include the possible human carcinogens for which, at a minimum, there are data sufficient for quantitative risk assessment, but for which data are inadequate for tier I value development due to a tumor response of marginal statistical significance or inability to derive a strong dose-response relationship. In determining whether to derive tier II human cancer values, available information on mode of action, such as mutagenicity/genotoxicity (determinations of whether the chemical interacts directly with DNA), structure activity, and metabolism shall also be considered. As with the use of data on possible human carcinogens in developing tier I values, the decision to use data on possible human carcinogens to derive tier II values shall be made on a case-by-case basis.(ii) To derive HNVs, all available toxicity data shall be evaluated. The full range of possible health effects of a chemical shall be considered in order to best describe the dose-response relationship of the chemical, and to calculate values which will protect against the most sensitive endpoint or endpoints of toxicity. Although it is desirable to have an extensive database that considers a wide range of possible adverse effects, this type of data exists for a very limited number of chemicals. For many others, there is a range in quality and quantity of data available. To assure minimum reliability of values, it is necessary to establish a minimum database with which to develop tier I or tier II values. The following procedures represent the minimum data sets necessary for this procedure: (A) The minimum data set sufficient to derive a tier I HNV shall include at least 1 well-conducted epidemiologic study or animal study. A well- conducted epidemiologic study shall quantify exposure levels and demonstrate positive association between exposure to a chemical and adverse effects in humans. A well-conducted study in animals shall demonstrate a dose-response relationship involving 1 or more critical effects biologically relevant to humans. Ideally, the duration of a study should span multiple generations of exposed test species or at least a major portion of the lifespan of 1 generation. This type of data is currently very limited. By the use of uncertainty adjustments, shorter- term studies, such as 90-day subchronic studies, with evaluation of more limited effects, may be used to extrapolate to longer exposures or to account for a variety of adverse effects. For tier I values developed pursuant to this procedure, such a limited study shall be conducted for not less than 90 days in rodents or for 10% of the lifespan of other appropriate test species and shall demonstrate a no observable adverse effect level (NOAEL). Chronic studies of 1 year or longer with rodents or 50% of the lifespan or longer with other appropriate test species that demonstrate a lowest observable adverse effect level (LOAEL) may be sufficient for use in tier I value derivation if the effects observed at the LOAEL were relatively mild and reversible as compared to effects at higher doses. This does not preclude the use of a LOAEL from a study of chronic duration with only 1 or 2 doses if the effects observed appear minimal when compared to effect levels observed at higher doses in other studies.(B) If the minimum data for deriving tier I values are not available to meet the tier I data requirements, then a more limited data base may be considered for deriving tier II values. As with tier I, all available data shall be considered and ideally should address a range of adverse health effects with exposure over a substantial portion of the lifespan, or multiple generations, of the test species. If such data are lacking, it may be necessary to rely on less extensive data to establish a tier II value. With the use of appropriate uncertainty factors to account for a less extensive database, the minimum data sufficient to derive a tier II value shall include a NOAEL from at least 1 well-conducted short-term repeated dose study. The study shall be conducted with animals, be of not less than 28 days duration, demonstrate a dose-response, and involve effects biologically relevant to humans. Data from studies of longer duration (more than 28 days) that may demonstrate other study conditions, as well as LOAELs from the studies (more than 28 days), may be more appropriate in some cases for derivation of tier II values. Use of a LOAEL should be based on consideration of the severity of effect, the quality of the study, and the duration of the study.(iii) Bioaccumulation factor minimum data requirements for tier determination include the following: (A) To be considered a tier I cancer or noncancer human health value, along with satisfying the minimum toxicity data requirements of paragraphs (i)(A) and (ii)(A) of this subdivision, an organic chemical shall meet 1 of the following bioaccumulation data requirements: (1) A field-measured BAF.(2) A BAF derived using the BSAF methodology.(3) A chemical that has a BAF of less than 125 regardless of what method in subrule (5) of this rule was used to derive the BAF.(B) To be considered a tier I cancer or noncancer human health value, along with satisfying the minimum toxicity data requirements of paragraphs (i)(A) and (ii)(A) of this subdivision, an inorganic chemical, including organometals such as mercury, shall meet 1 of the following bioaccumulative data requirements:(1) A field-measured BAF.(2) A laboratory-measured BCF.(C) Cancer or noncancer human health values are considered tier II if they do not meet either the minimum toxicity data requirements of paragraphs (i)(A) and (ii)(A) of this subdivision or the minimum bioaccumulation data requirements of subparagraph (A) or (B) of this paragraph.(b) The fundamental principles for human health cancer values development are as follows: (i) A non-threshold mechanism of carcinogenesis shall be assumed unless biological data adequately demonstrate the existence of a threshold on a chemical-specific basis.(ii) All appropriate human epidemiologic data and animal cancer bioassay data shall be considered. Data specific to an environmentally appropriate route of exposure shall be used. Oral exposure is preferred over dermal and inhalation exposure since, in most cases, the exposure routes of greatest concern are fish consumption and drinking water/incidental ingestion. The risk associated dose shall be set at a level corresponding to an incremental cancer risk of 1 in 100,000. If acceptable human epidemiologic data are available for a chemical, then the data shall be used to derive the risk associated dose. If acceptable human epidemiologic data are not available, then the risk associated dose shall be derived from available animal bioassay data. Data from a species that is considered most biologically relevant to humans, that is, responds most like humans, is preferred where all other considerations regarding quality of data are equal. In the absence of data to distinguish the most relevant species, data from the most sensitive species tested, that is, the species showing a carcinogenic effect at the lowest administered dose, shall generally be used.(iii) If animal bioassay data are used and a non-threshold mechanism of carcinogenicity is assumed, then the data are fitted to a linearized multistage computer model, for example, a GLOBAL '86 or equivalent model. GLOBAL '86 is the linearized multistage model which was derived by Howe, Crump, and Van Landingham (1986) which the Unites States EPA uses to determine cancer potencies (Howe et al., 1986). The upper- bound 95% confidence limit on risk, or the lower 95% confidence limit on dose, at the 1 in 100,000 risk level shall be used to calculate a risk associated dose (RAD) for individual chemicals. Other models, including modifications or variations of the linear multistage model that are more appropriate to the available data may be used where scientifically justified.(iv) If the duration of the study is significantly less than the natural lifespan of the test animal, then the slope may be adjusted on a case-by- case basis to compensate for latent tumors that were not expressed.(v) A species scaling factor shall be used to account for differences between test species and humans. It shall be assumed that milligrams per surface area per day is an equivalent dose between species. All doses presented in mg/kg bodyweight will be converted to an equivalent surface area dose by raising the mg/kg dose to the 3/4 power. However, if adequate pharmacokinetic and metabolism studies are available, then these data may be factored into the adjustment for species differences on a case-by-case basis.(vi) Additional data selection and adjustment decisions shall also be made in the process of quantifying risk. Consideration shall be given to tumor selection for modeling, that is, pooling estimates for multiple tumor types and identifying and combining benign and malignant tumors. All doses shall be adjusted to give an average daily dose over the study duration. Adjustments in the rate of tumor response shall be made for early mortality in test species. The goodness-of-fit of the model to the data shall also be assessed.(vii) If a linear, non-threshold dose-response relationship is assumed, then the RAD shall be calculated using the following equation: Click Here To View Image
Where: RAD = risk associated dose in milligrams of toxicant per kilogram body weight per day (mg/kg/day).
0.00001 (1 x 10-5) = incremental risk of developing cancer equal to 1 in 100,000.
q1* = slope factor (mg/kg/day)-1 .
(viii) If human epidemiologic data or other biological data (animal), or both, indicate that a chemical causes cancer via a threshold mechanism, then the risk associated dose may, on a case-by-case basis, be calculated using a method that assumes a threshold mechanism is operative.(c) The fundamental principles for human health noncancer value development are as follows: (i) Noncarcinogens shall generally be assumed to have a threshold dose or concentration below which no adverse effects should be observed. Therefore, the noncancer value is the maximum water concentration of a substance at or below which a lifetime exposure from drinking the water, consuming fish caught in the water, and ingesting water as a result of participating in water-related recreation activities is likely to be without appreciable risk of deleterious effects.(ii) For some noncarcinogens, there may not be a threshold dose below which no adverse effects should be observed. Chemicals acting as genotoxic teratogens and germline mutagens are thought to possibly produce reproductive or developmental effects, or both, through a genetically linked mechanism that may have no threshold. Other chemicals also may not demonstrate a threshold. Values for these types of chemicals will be established on a case-by-case basis using appropriate assumptions reflecting the likelihood that no threshold exists.(iii) All appropriate human and animal toxicologic data shall be reviewed and evaluated. To the maximum extent possible, data most specific to the environmentally relevant route of exposure shall be used. Oral exposure is preferred over dermal and inhalation exposure since, in most cases, the exposure routes of greatest concern are fish consumption and drinking water/incidental ingestion. If acceptable human epidemiologic data are not available, then animal data from species most biologically relevant to humans shall be used. In the absence of data to distinguish the most relevant species, data from the most sensitive animal species tested, that is, the species showing a toxic effect at the lowest administered dose given a relevant route of exposure should generally be used.(iv) Minimum data requirements are specified in subdivision (a)(ii)(A) of this subrule. The experimental exposure level representing the highest level tested at which no adverse effects were demonstrated (NOAEL) from studies satisfying the minimum data requirements shall be used for value calculations. In the absence of a NOAEL, a LOAEL from studies satisfying the minimum data requirements may be used if based on relatively mild and reversible effects.(v) Uncertainty factors shall be used to account for the uncertainties in predicting acceptable dose levels for the general human population based upon experimental animal data or limited human data. The uncertainty factors shall be determined as follows: (A) An uncertainty factor of 1 to 10 shall be used when extrapolating from valid experimental results from studies on prolonged exposure to average healthy humans. This factor of up to tenfold is used to protect sensitive members of the human population.(B) An uncertainty factor of 1 to 10 shall be used when extrapolating from valid results of long-term studies on experimental animals when results of studies of human exposure are not available or are inadequate. When considered with subparagraph (A) of this paragraph, a factor of up to one hundredfold is used in extrapolating data from the average animal to protect sensitive members of the human population.(C) An uncertainty factor of 1 to 10 shall be used when extrapolating from animal studies for which the exposure duration is less than chronic, but more than subchronic (90 days or more in length), or when other significant deficiencies in study quality are present, and when useful long- term human data are not available. When considered with subparagraphs (A) and (B) of this paragraph, a factor of up to one thousandfold is used in extrapolating data from less than chronic, but more than subchronic, studies for average animals to protect sensitive members of the human population from chronic exposure.(D) An uncertainty factor of 1 to 3 shall be used when extrapolating from animal studies for which the exposure duration is less than subchronic (less than 90 days). When considered with subparagraphs (A) , (B), and (C) of this paragraph, a factor of up to 3 thousandfold is used in extrapolating data from less than subchronic studies for average animals to protect sensitive members of the human population from chronic exposure.(E) An additional uncertainty factor of 1 to 10 may be used when deriving a value from a LOAEL. The UF accounts for the lack of an identifiable NOAEL. The level of additional uncertainty applied may depend upon the severity and the incidence of the observed adverse effect.(F) An additional uncertainty factor of 1 to 10 may be applied when there are limited effects data or incomplete subacute or chronic toxicity data, for example, reproductive/developmental data. The level of quality and quantity of the experimental data available and structure-activity relationships may be used to determine the factor selected.(G) When deriving a UF for use in developing an HNV, the total uncertainty, as calculated following subparagraphs (A) to (F) of this paragraph, shall not exceed 10,000 for tier I values and 30,000 for tier II values.(vi) All study results shall be converted, as necessary, to the standard unit for acceptable daily exposure of milligrams of toxicant per kilogram of body weight per day (mg/kg/day). Doses shall be adjusted for continuous exposure (7 days/week, 24 hours/day).(vii) The acceptable daily exposure (ADE) shall be calculated as follows: Click Here To View Image
Where:
ADE = acceptable daily exposure in milligrams of toxicant per kilogram body weight per day (mg/kg/day).
NOAEL/LOAEL = the study NOAEL or LOAEL.
UF = the uncertainty factor derived in paragraph (v) of this subdivision.
(d) Human health cancer values shall be derived using the following equation:Click Here To View Image
Where:
HCV = human cancer value in milligrams per liter (mg/L).
RAD = risk associated dose in milligrams toxicant per kilogram body weight per day (mg/kg/day) that is associated with a lifetime incremental cancer risk equal to 1 in 100,000 for individual chemicals.
BW = weight of an average human (BW = 70 kg).
WCd = per capita water consumption, both drinking and incidental exposure, for surface waters specified in R 323.1100(8) = 2 liters/day, or
WCr = per capita incidental daily water ingestion for surface waters not specified in R 323.1100(8) = 0.01 liters/day.
FCTL3 = consumption of regionally caught trophic level 3 fish = 0.0036 kg/day.
FCTL4 = consumption of regionally caught trophic level 4 fish = 0.0114 kg/day.
BAF3 = bioaccumulation factor for trophic level 3 fish, as derived using the BAF methodology in subrule (5) of this rule.
BAF4 = bioaccumulation factor for trophic level 4 fish, as derived using the BAF methodology in subrule (5) of this rule.
Where:
HNV = human noncancer value in milligrams per liter (mg/l).
ADE = acceptable daily exposure in milligrams toxicant per kilogram body weight per day (mg/kg/day).
RSC = relative source contribution factor of 0.8. An RSC derived from actual exposure data may be developed on a case-by-case basis.
BW = weight of an average human (BW = 70 kg).
WCd = per capita water consumption, both drinking and incidental exposure, for surface waters specified in R 323.1100(8) = 2 liters/day, or
WCr = per capita incidental daily water ingestion for surface waters not specified in R 323.1100(8) = 0.01 liters/day.
FC TL3 = consumption of regionally caught trophic level 3 fish = 0.0036 kg/day.
FC TL4 = consumption of regionally caught trophic level 4 fish = 0.0114 kg/day.
BAF 3 = human health bioaccumulati on factor for edible portion of trophic level 3 fish , as derived using the BAF methodology in subrule (5) of this rule.
BAF 4 = human health bioaccumulati on factor for edible portion of trophic level 4 fish , as derived using the BAF methodology in subrule (5) of this rule.
(f) Determine, on the basis of all pertinent data available, whether the hum an health cancer and noncancer values derived are consistent with sound scientific evidence. If they are not, the values shall be adjusted to more appropriately reflect the weight of available scientific evidence.(g) The tierI and tierII human health values shall be applied as monthly a verages, and compliance shall be based on the average of all daily measurements taken at a site within thesame calendar month.(h) Human health values may be modified on a site - specific basis to be more or less stringent to reflect local environmental conditions or local hum an exposure. Less stringent human health values shall be protective of designated uses of the surface waters of the state and shall be based on sound scientific rationale. Any such modifications shall be derived by making appropriate site - specific adjustments to the methodology in this subrule and shall be approved by the department.