Section 303.331  Mississippi River North Temperature

Instead of the standards of 35 Ill. Adm. Code 302.211(e) the water temperature at representative locations in the main river of the Mississippi River from the Wisconsin border to the Rock River must not exceed the maximum limits in the following table during more than 1% of the hours in the 12-month period ending with any month.  The water temperature at these locations must not at any time exceed the maximum limits in the following table by more than 1.7 ºC (3 ºF).

(Source:  Amended at 47 Ill. Reg. 4575, effective March 23, 2023)