35 Ill. Adm. Code 370.540
Plant Outfalls
Section 370
Section 370.540 Plant
Outfalls
a) Discharge Impact Control
The outfall sewer shall be designed to discharge to the
receiving stream in a manner acceptable to the Agency. Consideration should be
given in each case to the following:
1) Preference for free fall or submerged discharge at the site
selected.
2) Utilization of cascade aeration of effluent discharge to
increase dissolved oxygen.
3) Limited or complete across-stream dispersion as needed to
protect aquatic life movement and growth in the immediate reaches of the
receiving stream.
b) Design and Construction
The outfall sewer shall be so constructed and protected
against the effects of flood water, waves, ice, or other hazards as to
reasonably insure its structural stability and freedom from stoppage. A
manhole should be provided at the shore end of all gravity sewers extending
into the receiving waters. Hazards to navigation shall be considered in
designing outfall sewers.
c) Sampling Provisions
All outfalls shall be designed so that a sample of the
effluent can be readily obtained at a point after the final treatment process
and before discharge to or mixing with the receiving waters.