- a) Gross beta concentrations must not exceed 100 picocuries per liter (pCi/L).
- b) Strontium 90 concentration must not exceed 2 picocuries per liter (pCi/L).
- c) The annual average radium 226 and 228 combined concentration must not exceed 3.75 picocuries per liter (pCi/L).
Except as provided in Section 302.102, all waters of the Lake Michigan Basin must meet the following concentrations:
(Source: Amended at 47 Ill. Reg. 4437, effective March 23, 2023)