Illinois Administrative Code
Title 35 - ENVIRONMENTAL PROTECTION
Part 302 - WATER QUALITY STANDARDS
Subpart E - LAKE MICHIGAN BASIN WATER QUALITY STANDARDS
Section 302.570 - Procedures for Deriving Bioaccumulation Factors for the Lake Michigan Basin
Current through Register Vol. 48, No. 38, September 20, 2024
A bioaccumulation factor (BAF) is used to relate the concentration of a substance in an aquatic organism to the concentration of the substance in the waters in which the organism resides when all routes of exposure (ambient water and food) are included. A BAF is used in the derivation of water quality criteria to protect wildlife and criteria and values to protect human health.
a) Selection of Data. BAFs can be obtained or developed from one of the following methods, listed in order of preference.
The concentration of particulate organic carbon (POC) and dissolved organic carbon (DOC) in the test solution must be either measured or reliably estimated.
Predicted baseline BCF = Kow.
b) Calculation of Baseline BAFs for Organic Chemicals
The most preferred BAF or BCF from above is used to calculate a baseline BAF which in turn is utilized to derive a human health or wildlife specific BAF.
C1 = Cb / f1
Where:
|
Cb |
= |
concentration of the organic chemical in the tissue of aquatic biota (either whole organism or specified tissue) (µg/g) |
|
f1 |
= |
fraction of the tissue that is lipid |
The fraction of the total chemical in the ambient water that is freely dissolved, ffd, must be calculated using the following equation:
ffd = 1 / {1 + [(DOC)(Kow)/10] + [(POC)(Kow)]}
Where:
|
DOC |
= |
concentration of dissolved organic carbon, kg of dissolved organic carbon/L of water |
|
Kow |
= |
octanol-water partition coefficient of the chemical |
|
POC |
= |
concentration of particulate organic carbon, kg of particulate organic carbon/L of water |
Baseline BAF = {[measured BAFtT / ffd] - 1}{1 / f1}
Where:
|
BAFtT |
= |
BAF based on total concentration in tissue and water of study organism and site |
|
f1 |
= |
fraction of the tissue of study organism that is lipid |
|
ffd |
= |
fraction of the total chemical that is freely dissolved in the ambient water |
(Baseline BAF)i = (baseline BAF)r (BSAF)i (Kow)i / (BSAF) r (Kow)r
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" |
BSAF = C1 / Csoc
Where:
|
C1 |
= |
the lipid-normalized concentration of the chemical in tissue |
|
Csoc |
= |
the organic carbon-normalized concentration of the chemical in sediment |
Csoc = Cs / foc
Where:
|
Cs |
= |
concentration of chemical in sediment (µg/g sediment) |
|
foc |
= |
fraction of the sediment that is organic carbon |
baseline BAF = (FCM) {[measured BCFtT / ffd] - 1} {1 /f1}
Where:
|
BCFtT |
= |
BCF based on total concentration in tissue and water. |
|
f1 |
= |
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 B-1 in Appendix B to 40 CFR 132,, incorporated by reference at 35 Ill. Adm. Code 301.106, by linear interpolation for trophic level 3 or 4, as necessary |
baseline BAF = (FCM) (predicted baseline BCF) = (FCM)(Kow)
Where:
|
FCM |
= |
the food-chain multiplier obtained from Table B-1 in Appendix B to 40 CFR 132, incorporated by reference at 35 Ill. Adm. Code 301.106, by linear interpolation for trophic level 3 or 4, as necessary |
|
Kow |
= |
octanol-water partition coefficient |
c) Human Health and Wildlife BAFs for Organic Chemicals
ffd = 1 / [1+ (0.00000024 kg/L)(Kow)]
Human Health BAFHHTL3 = [(baseline BAF)(0.0182) + 1] (ffd)
Human Health BAFHHTL4 = [(baseline BAF) (0.0310) + 1] (ffd)
Where:
0.0182 and 0.0310 are the standardized fraction lipid values for trophic levels 3 and 4, respectively, that are used to derive human health criteria and values
Wildlife BAFWLTL3 = [(baseline BAF)(0.0646) +1] (ffd)
Wildlife BAFWLTL4 = [(baseline BAF)(0.1031) + 1] (ffd)
Where:
0.0646 and 0.1031 are the standardized fraction lipid values for trophic levels 3 and 4, respectively, that are used to derive wildlife criteria
d) Human Health and Wildlife BAFs for Inorganic Chemicals. For inorganic chemicals, the baseline BAFs for trophic levels 3 and 4 are both assumed to equal the BCF determined for the chemical with fish.
