The usual interval
Three to five years is the common range for a typical home. A full house on a small tank may need pumping closer to three years. A small household on a large tank can sometimes go longer.
Signs you should not wait
Slow drains in more than one fixture, gurgling, sewage odors, or wet ground over the tank or field mean schedule pumping now, not at the next anniversary.
Yale and St. Clair County
Rural lots and older tanks are common here. If you do not know the last pump date, treat it as overdue and book an inspection with pumping.