Septic soil in Cass County, MO, by the numbers

Very limited

Soil across 98.6% of Cass County, MO rates "Very limited" in USDA's septic-absorption-field interpretation. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 98.6% of the county. Cass County, MO is 696.618 square miles with a population of 113,873.

What Cass County's reading doesn't cover

USDA's survey covers the whole of Cass County, MO at once, not any single address. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Cass County will actually do.

What a system would cost here

With 98.6% of Cass County rating "Very limited", a standard gravity system is not a safe assumption here. The engineered-system range, $10,000-$40,000 (mound or aerobic treatment), is the more realistic number to plan around, against $3,000-$8,000 for a conventional system on the rare lot that passes.

Where this sits nationally

Nationally, Cass County, MO is the 143-most-constrained of 3,058 rated counties for septic soil. Within Missouri alone it ranks 20 of 114.

Before you act on this

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