Section 302.580  Procedures for Deriving Water Quality Criteria and Values in the Lake Michigan Basin to Protect Human Health - General  

a)         The Lake Michigan Basin human health criteria or values for a substance are those concentrations at which humans are protected from adverse effects resulting from incidental exposure to, or ingestion of, the waters of Lake Michigan and from ingestion of aquatic organisms taken from the waters of Lake Michigan.  A Lake Michigan Human Health Threshold Criterion (LMHHTC) or Lake Michigan Human Health Threshold Value (LMHHTV) will be calculated for all substances according to Section 302.585, if data is available.  Water quality criteria or values for substances that are, or may be, carcinogenic to humans will also be calculated according to procedures for the Lake Michigan Human Health Nonthreshold Criterion (LMHHNC) or the Lake Michigan Human Health Nonthreshold Value (LMHHNV) in Section 302.590.

b)         Minimum data requirements for BAFs for Lake Michigan Basin human health criteria:

1)         Tier I

A)        For all organic chemicals, either a field-measured BAF or a BAF derived using the BSAF methodology is required unless the chemical has a BAF less than 125, then a BAF derived by any methodology is required; and

B)        For all inorganic chemicals, including organometals such as mercury, either a field-measured BAF or a laboratory-measured BCF is required.

2)         Tier II. Any bioaccumulation factor method in Section 302.570(a) may be used to derive a Tier II criterion.

(Source:  Amended at 47 Ill. Reg. 4437, effective March 23, 2023)