What Knox County, MO's soil rates for a septic system
Very limited
99.6% of Knox County, MO's surveyed soil comes back "Very limited" in USDA's own SSURGO data, the county's dominant condition for a septic absorption field. That reading means a conventional system is a poor bet here - 99.6% of Knox County lands in the strictest "very limited" bucket USDA uses. Knox County, MO is 504.01 square miles with a population of 3,740.
What Knox County's reading doesn't cover
Nothing about Knox County, MO's SSURGO figure applies to a specific address - it's a county-wide average. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Knox County will actually do.
What a system would cost here
With 99.6% of Knox 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 Knox County, MO compares
Nationally, Knox County, MO is the 19-most-constrained of 3,058 rated counties for septic soil. Within Missouri alone it ranks 2 of 114.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems