eLaws | eCases | State of Indiana |
 Indiana Administrative Code (Last Updated: December 20, 2016)
 Title 327. WATER POLLUTION CONTROL DIVISION
 Article 327IAC2. WATER QUALITY STANDARDS
 Rule 327IAC2-1.5. Water Quality Standards Applicable to All State Waters Within the Great Lakes System

  Section 327IAC2-1.5-13. Determination of bioaccumulation factors (BAFs)  

Latest version.

  •    (a) This section describes procedures for deriving bioaccumulation factors (BAFs) to be used in the calculation of human health Tier I criteria and Tier II values and wildlife Tier I criteria. A subset of the human health BAFs is also used to identify the chemicals that are considered bioaccumulative chemicals of concern (BCCs). BAFs are derived as follows:

    (1) Bioaccumulation reflects uptake of a substance by aquatic organisms exposed to the substance through all routes, such as ambient water and food, as would occur in nature. Bioconcentration reflects uptake of a substance by aquatic organisms exposed to the substance only through the ambient water. Both BAFs and bioconcentration factors (BCFs) are proportionality constants that describe the relationship between the concentration of a substance in aquatic organisms and its concentration in the ambient water. In this section, BAFs, rather than BCFs, are used to calculate Tier I criteria for human health and wildlife and Tier II values for human health because they better account for the total exposure of aquatic organisms to chemicals.

    (2) For organic chemicals, the lipid content of the aquatic organisms is used to account for partitioning of organic chemicals within organisms so that data from different tissues and species can be integrated. The baseline BAF is based on the concentration of freely dissolved organic chemicals in the ambient water to facilitate extrapolation from one (1) water to another. Baseline BAFs shall be derived using one (1) of the following four (4) methods:

    (A) Measured baseline BAFs are derived from field-measured BAFs.

    (B) Predicted baseline BAFs are derived using biota-sediment accumulation factors (BSAFs).

    (C) Predicted baseline BAFs are derived by multiplying a laboratory-measured BCF by a food-chain multiplier (FCM).

    (D) Predicted baseline BAFs are derived by multiplying a predicted BCF by a FCM.

    (3) For inorganic chemicals, BAFs are assumed to equal BCFs (that is, the FCM is one (1.0)) unless chemical-specific biomagnification data support using a FCM other than one (1.0). The baseline BAFs are derived using either of the following two (2) methods:

    (A) Field-measured BAFs.

    (B) By multiplying laboratory-measured BCFs by a FCM.

    (4) Because both humans and wildlife consume fish from both trophic levels three (3) and four (4), two (2) baseline BAFs are needed to calculate either a human health criterion or value or a wildlife criterion for a chemical. When appropriate, ingestion through consumption of invertebrates, plants, mammals, and birds in the diet of wildlife species to be protected may be taken into account.

      (b) The following procedures shall be used to review and select the data necessary to determine BAFs, BSAFs, and BCFs:

    (1) Measured BAFs, BSAFs, and BCFs are assembled from available sources, including the following:

    (A) U.S. EPA Ambient Water Quality Criteria documents issued after January 1, 1980.

    (B) Published scientific literature.

    (C) Reports issued by U.S. EPA or other reliable sources.

    (D) Unpublished data.

    (E) Sources referenced in the Aquatic Toxicity Information Retrieval (AQUIRE) database.

    (2) The following procedural and quality assurance requirements shall be met for field-measured BAFs:

    (A) The field studies used shall be limited to those conducted in the Great Lakes system with fish at or near the top of the aquatic food chain, for example, in trophic levels three (3) or four (4).

    (B) The trophic level of the fish species shall be determined.

    (C) The site of the field study should not be so unique that the BAF cannot be extrapolated to other locations where the criteria and values will apply.

    (D) For organic chemicals, the percent lipid shall be either measured or reliably estimated for the tissue used in the determination of the BAF.

    (E) The concentration of the chemical in the water shall be measured in a way that can be related to particulate organic carbon (POC) or dissolved organic carbon (DOC) and should be relatively constant during the steady-state time period.

    (F) For organic chemicals with log KOW greater than four (4), the concentrations of POC and DOC in the ambient water shall be either measured or reliably estimated.

    (G) For inorganic and organic chemicals, BAFs shall be used only if they are expressed on a wet weight basis; BAFs reported on a dry weight basis cannot be converted to wet weight unless a conversion factor is measured or reliably estimated for the tissue used in the determination of the BAF.

    (3) The following procedural and quality assurance requirements shall be met for field-measured BSAFs:

    (A) The field studies used shall be limited to those conducted in the Great Lakes system with fish at or near the top of the aquatic food chain, for example, in trophic levels three (3) or four (4).

    (B) Samples of surface sediments (zero (0) to one (1) centimeter is ideal) shall be from locations in which there is net deposition of fine sediment and is representative of average surface sediment in the vicinity of the organism.

    (C) The KOWs used shall be of acceptable quality as described in subdivision (6).

    (D) The site of the field study should not be so unique that the resulting BAF cannot be extrapolated to other locations where the criteria and values will apply.

    (E) The trophic level of the fish species shall be determined.

    (F) The percent lipid shall be either measured or reliably estimated for the tissue used in the determination of the BAF.

    (4) The following procedural and quality assurance requirements shall be met for laboratory-measured BCFs:

    (A) The test organism shall not be diseased, unhealthy, or adversely affected by the concentration of the chemical.

    (B) The total concentration of the chemical in the water shall be measured and should be relatively constant during the steady-state time period.

    (C) The organisms shall be exposed to the chemical using a flow-through or renewal procedure.

    (D) For organic chemicals, the percent lipid shall be either measured or reliably estimated for the tissue used in the determination of the BCF.

    (E) For organic chemicals with log KOW greater than four (4), the concentrations of POC and DOC in the test solution shall be either measured or reliably estimated.

    (F) Laboratory-measured BCFs should be determined using fish species, but BCFs determined with molluscs and other invertebrates may be used with caution. For example, because invertebrates metabolize some chemicals less efficiently than vertebrates, a baseline BCF determined for such a chemical using invertebrates is expected to be higher than a comparable baseline BCF determined using fish.

    (G) If laboratory-measured BCFs increase or decrease as the concentration of the chemical increases in the test solutions in a bioconcentration test, the BCF measured at the lowest test concentration that is above concentrations existing in the control water shall be used, for example, a BCF should not be calculated from a control treatment. The concentrations of an inorganic chemical in a bioconcentration test should be greater than normal background levels and greater than levels required for normal nutrition of the test species if the chemical is a micronutrient, but below levels that adversely affect the species. Bioaccumulation of an inorganic chemical might be overestimated if concentrations are at or below normal background levels due to, for example, nutritional requirements of the test organisms.

    (H) For inorganic and organic chemicals, BCFs shall be used only if they are expressed on a wet weight basis. BCFs reported on a dry weight basis cannot be converted to wet weight unless a conversion factor is measured or reliably estimated for the tissue used in the determination of the BAF.

    (I) BCFs for organic chemicals may be based on measurement of radioactivity only when the BCF is intended to include metabolites or when there is confidence that there is no interference due to metabolites.

    (J) The calculation of the BCF must appropriately address growth dilution.

    (K) Other aspects of the methodology used shall be similar to those described by ASTM, 1990, Standard Practice for Conducting Bioconcentration Tests with Fishes and Saltwater Bivalve Molluscs, Standard E 1022.

    (5) The following procedural and quality assurance requirements shall be met for predicted BCFs:

    (A) The KOW used shall be of acceptable quality as described in subdivision (6).

    (B) The predicted baseline BCF shall be calculated using the equation:

    predicted baseline BCF = KOW

    Where:

    KOW

    =

    octanol-water partition coefficient.

    (6) The value of KOW shall be determined as follows:

    (A) The value of KOW used for an organic chemical shall be determined by giving priority to the experimental and computational techniques used as follows:

    (i) Where the Log KOW is less than four (4) (Log KOW < 4):

    Priority

    Technique

    1

    Slow-stir

    1

    Generator-column

    1

    Shake-flask

    2

    Reverse-phase liquid chromatography on C18 chromatography packing with extrapolation to zero percent solvent

    3

    Reverse-phase liquid chromatography on C18 chromatography packing without extrapolation to zero percent solvent

    4

    Calculated by the CLOGP program

    (ii) Where the Log KOW is greater than four (4) (Log KOW > 4):

    Priority

    Technique

    1

    Slow-stir

    1

    Generator-column

    2

    Reverse-phase liquid chromatography on C18 chromatography packing with extrapolation to zero percent solvent

    3

    Reverse-phase liquid chromatography on C18 chromatography packing without extrapolation to zero percent solvent

    4

    Shake-flask

    5

    Calculated by the CLOGP program

    (B) The CLOGP program is a computer program available from Pomona College. A value of KOW that seems to be different from the others should be considered an outlier and not used. The value of KOW used for an organic chemical shall be the geometric mean of the available KOWs with highest priority or can be calculated from the arithmetic mean of the available log KOWs with the highest priority. Because it is an intermediate value in the derivation of a BAF, the value used for the KOW of a chemical should not be rounded to fewer than three (3) significant digits and a value for log KOW should not be rounded to fewer than three (3) significant digits after the decimal point.

    (7) This section provides overall guidance for the derivation of BAFs, but it cannot cover all the decisions that must be made in the review and selection of acceptable data. Professional judgment is required throughout the process. A degree of uncertainty is associated with the determination of any BAF, BSAF, BCF, or KOW. The amount of uncertainty in a baseline BAF depends on both the quality of data available and the method used to derive the BAF.

    (8) Hereinafter in this section, "BAF", "BSAF", "BCF", and "KOW" refer to the "BAF", "BSAF", "BCF", and "KOW" that are consistent with the procedural and quality assurance requirements given in this subsection.

      (c) For comparative purposes, baseline BAFs should be derived for each chemical by as many of the four (4) methods as available data allow. Baseline BAFs shall be derived using the following four (4) methods, which are listed from most preferred to least preferred:

    (1) A measured baseline BAF for an organic or inorganic chemical derived from a field study of acceptable quality.

    (2) A predicted baseline BAF for an organic chemical derived using field-measured BSAFs of acceptable quality.

    (3) A predicted baseline BAF for an organic or inorganic chemical derived from a BCF measured in a laboratory study of acceptable quality and an FCM.

    (4) A predicted baseline BAF for an organic chemical derived from a KOW of acceptable quality and an FCM.

      (d) The following procedures shall be used to calculate baseline BAFs for organic chemicals:

    (1) The following procedures shall be used to determine the lipid-normalized concentration:

    (A) It is assumed that BAFs and BCFs for organic chemicals can be extrapolated on the basis of percent lipid from one (1) tissue to another and from one (1) aquatic species to another in most cases.

    (B) Because BAFs and BCFs for organic chemicals are related to the percent lipid, it does not make any difference whether the tissue sample is whole body or edible portion, but both the BAF (or BCF) and the percent lipid must be determined for the same tissue. The percent lipid of the tissue should be measured during the BAF or BCF study, but in some cases it can be reliably estimated from measurements on tissue from other organisms. If percent lipid is not reported for the test organisms in the original study, it may be obtained from the author; or, in the case of a laboratory study, lipid data for the same or a comparable laboratory population of test organisms that were used in the original study may be used.

    (C) The lipid-normalized concentration, Cℓ, of a chemical in tissue is defined using the following equation:

    Where:

    CB

    =

    concentration of the organic chemical in the tissue of aquatic biota (either whole organism or specified tissue) (micrograms per gram).

     

    fℓ

    =

    fraction of the tissue that is lipid.

    (2) By definition, baseline BAFs and BCFs for organic chemicals, whether measured or predicted are based on the concentration of the chemical that is freely dissolved in the ambient water in order to account for bioavailability. The following procedures shall be used to determine this freely dissolved concentration:

    (A) For the purposes of this subsection, the relationship between the total concentration of the chemical in the water (that which is freely dissolved plus that which is sorbed to particulate organic carbon or to dissolved organic carbon) to the freely dissolved concentration of the chemical in the ambient water shall be calculated using the following equation:

    Where:

    Cd

    =

    freely dissolved concentration of the organic chemical in the ambient water.

     

    C

    =

    total concentration of the organic chemical in the ambient water.

     

    ffd

    =

    fraction of the total chemical in the ambient water that is freely dissolved.

    (B) The fraction of the total chemical in the ambient water that is freely dissolved, ffd, shall be calculated using the following equation:

    Where:

    DOC

    =

    concentration of dissolved organic carbon in kilograms of dissolved organic carbon per liter of water.

     

    KOW

    =

    octanol-water partition coefficient of the chemical.

     

    POC

    =

    concentration of particulate organic carbon in kilograms of particulate organic carbon per liter of water.

    (3) In the absence of a field-measured BAF or a predicted BAF derived from a BSAF, a food chain multiplier (FCM) shall be used to calculate the baseline BAF for trophic levels three (3) and four (4) from a laboratory-measured or predicted BCF. For an organic chemical, the FCM used shall be derived from Table 13-1 in subsection (h), using the chemical's log KOW and linear interpolation. An FCM greater than one (1.0) applies to most organic chemicals with a log KOW of four (4) or more. The trophic level used shall take into account the age or size of the fish species consumed by the human, avian, or mammalian predator because, for some species of fish, the young are in trophic level three (3) whereas the adults are in trophic level four (4).

    (4) A baseline BAF shall be calculated from a field-measured BAF of acceptable quality using the following equation:

    Where:

    BAF

    =

    BAF based on total concentration in tissue and water.

     

    fℓ

    =

    fraction of the tissue that is lipid.

     

    ffd

    =

    fraction of the total chemical that is freely dissolved in the ambient water.

    The trophic level to which the baseline BAF applies is the same as the trophic level of the organisms used in the determination of the field-measured BAF. For each trophic level, a species mean measured baseline BAF shall be calculated as the geometric mean if more than one (1) measured baseline BAF is available for a given species. For each trophic level, the geometric mean of the species mean measured baseline BAFs shall be calculated. If a baseline BAF based on a measured BAF is available for either trophic level three (3) or four (4), but not both, a measured baseline BAF for the other trophic level shall be calculated using the ratio of the FCMs that are obtained by linear interpolation from Table 13-1 in subsection (h) for the chemical.

    (5) A baseline BAF shall be calculated from a field-measured BAF in accordance with the following:

    (A) A baseline BAF for organic chemical "i" shall be calculated from a field-measured BSAF of acceptable quality using the following equation:

    Where:

    (BSAF)i

    =

    BSAF for chemical "i".

     

    (BSAF)r

    =

    BSAF for the reference chemical "r".

     

    (KOW)i

    =

    octanol-water partition coefficient for chemical "i".

     

    (KOW)r

    =

    octanol-water partition coefficient for the reference chemical "r".

    (B) A BSAF shall be calculated using the following equation:

    Where:

    Cℓ

    =

    the lipid-normalized concentration of the chemical in tissue.

     

    CSOC

    =

    the organic carbon-normalized concentration of the chemical in sediment.

    (C) The organic carbon-normalized concentration of a chemical in sediment, CSOC, shall be calculated using the following equation:

    Where:

    CS

    =

    concentration of chemical in sediment (micrograms per gram of sediment).

     

    fOC

    =

    fraction of the sediment that is organic carbon.

    (D) Predicting BAFs from BSAFs requires data from a steady-state (or near steady-state) condition between sediment and ambient water for both a reference chemical "r" with a field-measured BAFd and other chemicals "n = i" for which BSAFs are to be determined.

    (E) The trophic level to which the baseline BAF applies is the same as the trophic level of the organisms used in the determination of the BSAF. For each trophic level, a species mean baseline BAF shall be calculated as the geometric mean if more than one (1) baseline BAF is predicted from BSAFs for a given species. For each trophic level, the geometric mean of the species mean baseline BAFs derived using BSAFs shall be calculated.

    (F) If a baseline BAF based on a measured BSAF is available for either trophic level three (3) or four (4), but not both, a baseline BAF for the other trophic level shall be calculated using the ratio of the FCMs that are obtained by linear interpolation from Table 13-1 in subsection (h) for the chemical.

    (6) A baseline BAF for trophic level three (3) and a baseline BAF for trophic level four (4) shall be calculated from a laboratory-measured BCF of acceptable quality and a FCM using the following equation:

    Where:

    BCF

    =

    BCF based on total concentration in tissue and water.

     

    fℓ

    =

    fraction of the tissue that is lipid.

     

    ffd

    =

    fraction of the total chemical in the test water that is freely dissolved.

     

    FCM

    =

    the food-chain multiplier obtained from Table 13-1 in subsection (h) by linear interpolation for trophic level three (3) or four (4) as necessary.

    For each trophic level, a species mean baseline BAF shall be calculated as the geometric mean if more than one (1) baseline BAF is predicted from laboratory-measured BCFs for a given species. For each trophic level, the geometric mean of the species mean baseline BAFs based on laboratory-measured BCFs shall be calculated.

    (7) A baseline BAF for trophic level three (3) and a baseline BAF for trophic level four (4) shall be calculated from a KOW of acceptable quality and a FCM using the following equation:

    Where:

    FCM

    =

    the food-chain multiplier obtained from Table 13-1 in subsection (h) by linear interpolation for trophic level three (3) or four (4) as necessary.

     

    KOW

    =

    octanol-water partition coefficient.

      (e) The following procedures shall be used to calculate human health and wildlife BAFs for organic chemicals:

    (1) To calculate human health and wildlife BAFs for an organic chemical, the KOW of the chemical shall be used with a POC concentration of 0.00000004 kilograms per liter and a DOC concentration of 0.000002 kilograms per liter to yield the fraction freely dissolved:

     

    (2) The human health BAFs for an organic chemical shall be calculated using the following equations:

    (A) For trophic level three (3):

    Human Health = [(baseline BAF)(0.0182)+ 1](ffd)

    Where:

    0.0182 is the standardized fraction lipid values for trophic level three (3) that is used to derive human health criteria and values.

    (B) For trophic level four (4):

    Human Health = [(baseline BAF)(0.0310)+ 1](ffd)

    Where:

    0.0310 is the standardized fraction lipid values for trophic level four (4) that is used to derive human health criteria and values.

    (3) The wildlife BAFs for an organic chemical shall be calculated using the following equations:

    (A) For trophic level three (3):

    Wildlife = [(baseline BAF)(0.0646)+ 1](ffd)

    Where:

    0.0646 is the standardized fraction lipid value for trophic level three (3) that is used to derive wildlife criteria.

    (B) For trophic level four (4):

    Wildlife = [(baseline BAF)(0.1031)+ 1](ffd)

    Where:

    0.1031 is the standardized fraction lipid values for trophic level four (4) that is used to derive wildlife criteria.

      (f) The following procedures shall be used to calculate human health and wildlife BAFs for inorganic chemicals:

    (1) For inorganic chemicals, the baseline BAFs for trophic levels three (3) and four (4) are both assumed to equal the BCF determined for the chemical with fish, for example, the FCM is assumed to be one (1) for both trophic levels three (3) and four (4). However, an FCM greater than one (1) might be applicable to some metals, such as mercury, if, for example, an organometallic form of the metal biomagnifies.

    (2) The following procedures shall be used to calculate human health BAFs for inorganic chemicals:

    (A) Measured BAFs and BCFs used to determine human health BAFs for inorganic chemicals shall be based on edible tissue, such as muscle, of freshwater fish unless it is demonstrated that whole body BAFs or BCFs are similar to edible tissue BAFs or BCFs. BCFs and BAFs based on measurements of aquatic plants and invertebrates should not be used in the derivation of human health criteria and values.

    (B) If one (1) or more field-measured baseline BAFs for an inorganic chemical are available from studies conducted in the Great Lakes system with the muscle of fish:

    (i) for each trophic level, a species mean measured baseline BAF shall be calculated as the geometric mean if more than one (1) measured BAF is available for a given species; and

    (ii) for each trophic level, the geometric mean of the species mean measured baseline BAFs shall be used as the human health BAF for that chemical.

    (C) If an acceptable measured baseline BAF is not available for an inorganic chemical and one (1) or more acceptable edible portion laboratory measured BCFs are available for the chemical, a predicted baseline BAF shall be calculated by multiplying the geometric mean of the BCFs times a FCM. The FCM will be one (1.0) unless chemical-specific biomagnification data support using a multiplier other than one (1.0). The predicted baseline BAF shall be used as the human health BAF for that chemical.

    (3) The following procedures shall be used to calculate wildlife BAFs for inorganic chemicals:

    (A) Measured BAFs and BCFs used to determine wildlife BAFs for inorganic chemicals shall be based on whole body freshwater fish and invertebrate data unless it is demonstrated that edible tissue BAFs or BCFs are similar to whole body BAFs or BCFs.

    (B) If one (1) or more field-measured baseline BAFs for an inorganic chemical are available from studies conducted in the Great Lakes system with whole body of fish or invertebrates:

    (i) for each trophic level, a species mean measured baseline BAF shall be calculated as the geometric mean if more than one (1) measured BAF is available for a given species; and

    (ii) for each trophic level, the geometric mean of the species mean measured baseline BAFs shall be used as the wildlife BAF for that chemical.

    (C) If an acceptable measured baseline BAF is not available for an inorganic chemical and one (1) or more acceptable whole body laboratory measured BCFs are available for the chemical, a predicted baseline BAF shall be calculated by multiplying the geometric mean of the BCFs times a FCM. The FCM will be one (1.0) unless chemical-specific biomagnification data support using a multiplier other than one (1.0). The predicted baseline BAF shall be used as the wildlife BAF for that chemical.

      (g) For both organic and inorganic chemicals, human health and wildlife BAFs for both trophic levels shall be reviewed for consistency with all available data concerning the bioaccumulation, bioconcentration, and metabolism of the chemical. For example, information concerning octanol-water partitioning, molecular size, or other physicochemical properties that might enhance or inhibit bioaccumulation should be considered for organic chemicals. BAFs derived in accordance with this methodology should be modified if changes are justified by available data.

      (h) The following shall be used to obtain food chain multipliers:

    Table 13-1

    Food-Chain Multipliers for Trophic Levels 2, 3, and 4

    Log KOW

    T. L. 2

    T. L. 3a

    T. L. 4

    2.0

    1.000

    1.005

    1.000

    2.5

    1.000

    1.010

    1.002

    3.0

    1.000

    1.028

    1.007

    3.1

    1.000

    1.034

    1.007

    3.2

    1.000

    1.042

    1.009

    3.3

    1.000

    1.053

    1.012

    3.4

    1.000

    1.067

    1.014

    3.5

    1.000

    1.083

    1.019

    3.6

    1.000

    1.103

    1.023

    3.7

    1.000

    1.128

    1.033

    3.8

    1.000

    1.161

    1.042

    3.9

    1.000

    1.202

    1.054

    4.0

    1.000

    1.253

    1.072

    4.1

    1.000

    1.315

    1.096

    4.2

    1.000

    1.380

    1.13

    4.3

    1.000

    1.491

    1.178

    4.4

    1.000

    1.614

    1.242

    4.5

    1.000

    1.766

    1.334

    4.6

    1.000

    1.950

    1.459

    4.7

    1.000

    2.175

    1.633

    4.8

    1.000

    2.452

    1.871

    4.9

    1.000

    2.780

    2.193

    5.0

    1.000

    3.181

    2.612

    5.1

    1.000

    3.643

    3.162

    5.2

    1.000

    4.188

    3.873

    5.3

    1.000

    4.803

    4.742

    5.4

    1.000

    5.502

    5.821

    5.5

    1.000

    6.266

    7.079

    5.6

    1.000

    7.096

    8.551

    5.7

    1.000

    7.962

    10.209

    5.8

    1.000

    8.841

    12.050

    5.9

    1.000

    9.716

    13.964

    6.0

    1.000

    10.556

    15.996

    6.1

    1.000

    11.337

    17.783

    6.2

    1.000

    12.064

    19.907

    6.3

    1.000

    12.691

    21.677

    6.4

    1.000

    13.228

    23.281

    6.5

    1.000

    13.662

    24.604

    6.6

    1.000

    13.980

    25.645

    6.7

    1.000

    14.223

    26.363

    6.8

    1.000

    14.355

    26.669

    6.9

    1.000

    14.388

    26.669

    7.0

    1.000

    14.305

    26.242

    7.1

    1.000

    14.142

    25.468

    7.2

    1.000

    13.852

    24.322

    7.3

    1.000

    13.474

    22.856

    7.4

    1.000

    12.987

    21.038

    7.5

    1.000

    12.517

    18.967

    7.6

    1.000

    11.708

    16.749

    7.7

    1.000

    10.914

    14.388

    7.8

    1.000

    10.069

    12.050

    7.9

    1.000

    9.162

    9.840

    8.0

    1.000

    8.222

    7.798

    8.1

    1.000

    7.278

    6.012

    8.2

    1.000

    6.361

    4.519

    8.3

    1.000

    5.489

    3.311

    8.4

    1.000

    4.683

    2.371

    8.5

    1.000

    3.949

    1.663

    8.6

    1.000

    3.296

    1.146

    8.7

    1.000

    2.732

    0.778

    8.8

    1.000

    2.246

    0.521

    8.9

    1.000

    1.837

    0.345

    9.0

    1.000

    1.493

    0.226

    aThe FCMs for trophic level 3 are the geometric mean of the FCMs for sculpin and alewife.

    (Water Pollution Control Division; 327 IAC 2-1.5-13; filed Jan 14, 1997, 12:00 p.m.: 20 IR 1392; errata filed Aug 11, 1997, 4:15 p.m.: 20 IR 3377)