Septic soil in Callaway County, MO, by the numbers

Very limited

Soil across 98.1% of Callaway County, MO rates "Very limited" in USDA's septic-absorption-field interpretation. Practically, that rules out a simple gravity system for most of the county - 98.1% of it sits in USDA's most-constrained bucket. Callaway County, MO is 834.565 square miles with a population of 45,126.

What Callaway County's reading doesn't cover

Two lots a mile apart in Callaway County can carry different soil, even though they share one countywide rating. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Callaway County will actually do.

What a system would cost here

With 98.1% of Callaway 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.

How Callaway County, MO compares

Nationally, Callaway County, MO is the 229-most-constrained of 3,058 rated counties for septic soil. Within Missouri alone it ranks 30 of 114.

Before you act on this

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