Section 302.503  pH

pH (STORET number 00400) must be within the range of 7.0 to 9.0, except for natural causes, in the Open Waters of Lake Michigan as defined at Section 302.501.  Other waters of the Basin must be within the range of 6.5 to 9.0, except for natural causes.

(Source:  Amended at 23 Ill. Reg. 11249, effective August 26, 1999)