77 Ill. Adm. Code 890.1030
Length and Grade
Section 890
Section 890.1030Â Length and
Grade
a)        Maximum Length. The maximum developed length of the indirect
waste of any sanitary waste line shall not exceed 5 feet.
b)        Grade. Indirect waste pipes shall be installed at a uniform
grade, in compliance with Section 890.1320(f), (g) and (h).