What Butler County, MO's soil rates for a septic system
Very limited
In Butler County, MO, 91.7% of the surveyed land carries a "Very limited" rating for a standard septic drain field. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 91.7% of the county. Butler County, MO is 694.754 square miles with a population of 41,814.
What Butler County's reading doesn't cover
USDA's survey covers the whole of Butler 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 Butler County will actually do.
What a system would cost here
With 91.7% of Butler 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, Butler County, MO is the 1,076-most-constrained of 3,058 rated counties for septic soil. Within Missouri alone it ranks 71 of 114.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems