Illinois Administrative Code
Title 35 - ENVIRONMENTAL PROTECTION
Part 302 - WATER QUALITY STANDARDS
Subpart E - LAKE MICHIGAN BASIN WATER QUALITY STANDARDS
Section 302.575 - Procedures for Deriving Tier I Water Quality Criteria and Values in the Lake Michigan Basin to Protect Wildlife
Current through Register Vol. 48, No. 38, September 20, 2024
The Lake Michigan Basin Wildlife Criterion (LMWC) is the concentration of a substance that, if not exceeded, protects Illinois wild mammal and bird populations from adverse effects resulting from the ingestion of surface waters of the Lake Michigan Basin or aquatic prey organisms taken from surface waters of the Lake Michigan Basin. Wildlife criteria calculated under this Section protect against long-term effects and are therefore considered chronic criteria. The methodology involves the use of data from test animals to derive criteria to protect representative or target species: bald eagle, herring gull, belted kingfisher, mink, and river otter. The lower of the geometric mean of species-specific criteria for bird species or mammal species is chosen as the LMWC to protect a broad range of species.
a) This method must also be used for non-BCCs when appropriately modified to consider the following factors:
b) Minimum Data Requirements
c) Principles for Developing Criteria
d) Calculation of TSV. The TSV, measured in milligrams per liter (mg/L), is calculated according to the equation:
TSV = {[TD x Wt] / [UFa x UFs x UF1]} / {W + [SIGMA][FTLi x BAFWLTLi]}
Where:
TSV |
= |
target species value in milligrams of substance per liter (mg/L). |
TD |
= |
test dose that is toxic to the test species, either NOAEL or LOAEL. |
UFa |
= |
the uncertainty factor for extrapolating toxicity data across species (unitless). A species-specific UFa must be selected and applied to each target species, consistent with the equation. |
Ufs |
= |
the uncertainty factor for extrapolating from subchronic to chronic exposures (unitless). |
Uf1 |
= |
the uncertainty factor for extrapolation from LOAEL to NOAEL (unitless). |
Wt |
= |
average weight in kilograms (kg) of the target species. |
W |
= |
average daily volume of water in liters consumed per day (L/d) by the target species. |
FTLi |
= |
average daily amount of food consumed by the target species in kilograms (kg/d) for trophic level i. |
BAFWLTLi |
= |
aquatic life bioaccumulation factor with units of liter per kilogram (L/kg), as derived from 35 Ill. Adm. Code 302.570 for trophic level i. |
e) Calculation of the Lake Michigan Basin Wildlife Criterion. TSVs are obtained for each target species. The geometric mean of the TSVs is calculated for all mammal species and all bird species. The LMWC is the lower of the bird or mammal geometric mean TSV.