Ill. Admin. Code tit. 35, § 301.365
"Publicly Owned Treatment Works" means a treatment works owned by a municipality, sanitary district, county, or state agency, and which treats domestic and industrial wastes collected by a publicly owned or regulated sewer system. Industrial treatment works which are publicly owned and financed by bond issues of public agencies are not included in this definition.
(Source: Amended at 47 Ill. Reg. 4415, effective March 23, 2023)