How often should a septic tank be pumped in Illinois?

Most septic tanks need pumping every 3–5 years for a typical household. The Illinois EPA recommends every 3 years as a general guideline.

Factors that affect frequency include household size, tank size, and whether you use a garbage disposal (which significantly increases solid waste load).

Aerobic septic systems have additional maintenance requirements — Illinois state law requires a licensed service contract for aerobic systems, with inspections every 6 months and annual pumping in most cases.