The General Use chronic water quality standard for cyanide in 35 Ill. Adm. Code 302.208 does not apply to Salt Creek, Higgins Creek, the West Branch of the DuPage River, and the Des Plaines River in Cook County, Illinois. Instead, for these waters the chronic cyanide standard is 10 µg/L.
Ill. Admin. Code tit. 35, § 303.444
Added at 20 Ill. Reg. 3534, effective February 8, 1996