Osage County's SSURGO septic rating
Very limited
Osage County, KS: USDA's soil survey calls 96.6% of the county "Very limited" for a septic leach field. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 96.6% of Osage County's land. The county spans 705.506 square miles, home to 15,737 people.
What this number does and doesn't tell you
Osage County's rating is an average across the whole county, not a promise about any one lot inside it. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Osage County: conventional vs. engineered cost
96.6% of Osage County carrying a "Very limited" reading changes the realistic budget here. 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.
Where this sits nationally
Among the 3,058 rated counties on this site, Osage County, KS ranks 440 most-constrained nationally, and 30 of 105 within Kansas.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems