35 Ill. Adm. Code 725.299
Special Requirements for Incompatible Wastes
Section 725
Section 725.299Â Special
Requirements for Incompatible Wastes
a)        Incompatible wastes or incompatible wastes and materials must
not be placed in the same tank system, unless Section 725.117(b) is complied
with.
b)Â Â Â Â Â Â Â Â Hazardous waste must not be placed in a tank system that has
not been decontaminated and which previously held an incompatible waste or
material unless Section 725.117(b) is complied with.