35 Ill. Adm. Code 301.440
Waters
Section 301
Section 301.440Â Waters
"Waters" means all
accumulations of water, surface and underground, natural, and artificial,
public and private, or parts thereof, which are wholly or partially within,
flow through, or border upon the State of Illinois, except that sewers and treatment
works are not included except as specially mentioned; provided, that nothing
herein contained shall authorize the use of natural or otherwise protected
waters as sewers or treatment works except that in-stream aeration under Agency
permits is allowable.