Cass County's SSURGO septic rating

Very limited

Cass County, IL's SSURGO dominant class comes back "Very limited", covering 69.9% of the county. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 69.9% of the county. For scale: 375.754 square miles and 12,713 people call Cass County home.

Before you rely on this for one lot

This is a countywide, area-weighted figure across every soil survey map unit in Cass County, IL - never a reading for one specific parcel. The real answer for one lot is still a site-specific perc test, running about $750-$1,850 (typically near $1,300).

Budgeting for a system in Cass County, IL

Cass County's soil reading pushes the likely outcome toward an engineered system rather than a conventional one. Conventional systems run $3,000-$8,000 where they pass; where they don't, engineered alternatives (mound or aerobic treatment, whichever the health department requires) run $10,000-$40,000 - budget toward the higher figure until a perc test says otherwise.

How Cass County, IL compares

Among the 3,058 rated counties on this site, Cass County, IL ranks 2,466 most-constrained nationally, and 81 of 101 within Illinois.

Further reading

How this rating is built, and its real limits · Conventional vs. engineered septic systems