Doniphan County's SSURGO septic rating
Very limited
USDA puts Doniphan County, KS at "Very limited" for septic absorption fields, the dominant reading across 69% of the county's soil. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 69% of the county. The county spans 393.475 square miles, home to 7,575 people.
What this number does and doesn't tell you
Two lots a mile apart in Doniphan County can carry different soil, even though they share one countywide rating. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Doniphan County: conventional vs. engineered cost
69% of Doniphan 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, Doniphan County, KS ranks 2,498 most-constrained nationally, and 81 of 105 within Kansas.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems