Ill. Admin. Code tit. 35 § 391.102
"Agronomic Rates for Sludge Application": An application rate of sludge sufficient to supply that quantity of plant nutrients that can reasonably be expected to be utilized by agricultural crops as determined pursuant to Section 391.410.
"Application": The placement of sludge on or under the land surface.
"Cation Exchange Capacity": The sum of exchangeable cations a soil can absorb expressed in milli-equivalents per 100 grams of soil as determined by the summation method for distinctly acid soils or the sodium acetate method for neutral, calcareous or saline soils.
"Digested Sludge": Sludge digested under either aerobic or anaerobic conditions until the volatile content has been reduced to the point at which the solids are relatively nonputrescible and inoffensive.
"Dried Sludge": Sludge that has been dewatered by a mechanical device, drying beds or other means such that it can be transported and handled as a solid material. Normally, this will be a minimum of 15% total solids.
"Heavy Metals": Metals with a high specific gravity, including but not limited to cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn), chromium (Cr), mercury (Hg), nickel (Ni).
"Incorporation": To mix sludge with the soil, concurrent with application, in the upper horizon by such means as injection, discing, or plowing.
"Liquid Sludge": Sludge that is readily pumpable and must be transported by a closed vessel. Normally, this will be a maximum of 8% total solids.
"Management Scheme or Management Plan": A program devised by a sludge generator or user that specifies how they will properly transport, store and dispose of sludge for which they are responsible. This would include but not be limited to on-site or off-site storage, seasonal operation, with all proposed disposal techniques and criteria to be followed.
"Natric Soils": Soils having 15% or more millequivalents of exchangeable sodium within the solum.
"Off-Site Interim Storage": The storage of sludge off the treatment plant site from where it was generated but does not include sludge in the transporting vehicle.
"Plant Nutrients": Those forms of nitrogen, phosphorus, potassium and micro-nutrients which are absorbed by agricultural crops and provide the necessary food for the plant's maintenance and growth.
"Public Distribution": A program by a sludge generator that allows the general public to obtain sludge for individual use but does not include sludge users who may be under contract with the sludge generator or persons receiving sludge for commercial agricultural use.
"Reclamation": The improvement of disturbed soils by addition of sludge materials which would allow the establishment and maintenance of vegetation.
"Sludge Distributor": A sludge user who is not a sludge generator but who sells or gives away sludge regardless of its origin.
"Sludge Generator": A person who produces sludge by treating water or wastewater by a treatment works or pretreatment works.
"Sludge User": A person who obtains sludge from a sludge generator for application on his land or land under his control.
"Stabilized Sludge": The product of biological, chemical, heat or other type of sludge treatment that results in a relatively nonputrescible and inoffensive material.
"Utilization": The application of sludge on land for agricultural, horticultural, silvicultural, or other beneficial purposes at such rates that the nutrients can be expected to be utilized by plant growth.
Ill. Admin. Code tit. 35, § 391.102