35 Ill. Adm. Code 501.380
Water Pollution
Section 501
Section 501.380 Water
Pollution
The alteration of the physical,
thermal, chemical, biological, or radioactive properties of any waters of the
State, or the discharge of any contaminant into any waters of the State, as
will or is likely to create a nuisance or render those waters harmful or
detrimental or injurious to public health, safety, or welfare, to domestic,
commercial, industrial, agricultural, recreational, or other legitimate uses,
or to humans, livestock, wild animals, birds, or fish or other aquatic life.