Ill. Admin. Code tit. 35 § 301.442
"Wet Weather Point Source" means any discernible, confined, and discrete conveyance from which pollutants are, or may be, discharged as the result of a wet weather event. Discharges from wet weather point sources must include only: discharges of stormwater from a municipal separate storm sewer as defined at 40 CFR 122.26(b)(8), incorporated by reference in Section 301.106; stormwater discharge associated with industrial activity as defined at 40 CFR 122.26(b)(14), incorporated by reference in Section 301.106; discharges of stormwater and sanitary wastewaters (domestic, commercial, and industrial) from a combined sewer overflow; or any other stormwater discharge for which a permit is required under Section 402(p) of the Clean Water Act (33 U.S.C. 1342(p)). A stormwater discharge associated with industrial activity that is mixed with process wastewater will not be considered a wet weather point source.
Ill. Admin. Code tit. 35, § 301.442
Added at 23 Ill. Reg. 11277, effective August 26, 1999