Septic Tank Companies in Illinois

Illinois septic systems are regulated by the Illinois Department of Public Health (IDPH) under the Private Sewage Disposal Code (77 Ill. Adm. Code 905), with permitting handled by local health departments in each of the state's 102 counties. The state's landscape is dominated by glacial till soils — deep, rich, and often heavy clay — left by the Wisconsin glaciation, which provide poor natural drainage across much of central and northern Illinois. Septic systems in Illinois are concentrated in rural areas outside the extensive municipal sewer networks serving Chicago, the collar counties, and the I-55 corridor, with the highest density in southern Illinois counties like Jackson, Williamson, and Saline where terrain is hillier and municipal infrastructure is sparse.