77 Ill. Adm. Code 906.20
Definitions
Section 906
Section 906.20Â Definitions
"Absorption
Area" means the area of coarse aggregate in the absorption bed or trenches
in a mound.
"Basal
Area" means the area of natural soil under a mound which is effective in
absorbing effluent.
"Depression"
means an area that is sunk below its surroundings.
"Dosing"
means the application of sewage under pressure to a sewage disposal system at constant
intervals or in constant amounts per application.
"Drainageway"
means a natural or artificial channel for the discharge of surface water
through a given tract of land or region.
"Flood
plain" means the land bordering a stream, built up of sediments from
overflow of the stream and subject to inundation when the stream is at flood
stage.
"Mound"
means a soil absorption sewage treatment system that is elevated above the
natural ground surface in a suitable fill material as defined in 906.40.
"Perched
Water Table" means groundwater which is trapped above a normal water table
by an impervious formation.
"Percolation
Rate" means the downward movement of water through a saturated soil.
"Permeable
Soil" means soil which has a percolation rate between 18 and 180 minutes.Â
(See Appendix A, Illustration G of the Private Sewage Disposal Code for meaning
of percolation rate and percolation test procedure.)
"Shallow
Permeable Soil" means pervious soil over creviced or porous bed rock, 5½
feet or less in thickness.
"Slowly
Permeable Soil" means soil having a percolation rate of between 180 and
360 minutes.