Ill. Admin. Code tit. 35, § 302.530
The Allowed Mixing, Mixing Zones, and ZIDs provisions of Section 302.102 apply within the Lake Michigan Basin except as otherwise provided for substances defined as BCCs in Section 302.501. Mixing is not allowed for BCCs for new discharges commencing on or after December 24, 1997.
(Source: Amended at 47 Ill. Reg. 4437, effective March 23, 2023)