Johnson County, KS: the USDA septic-suitability picture

Very limited

Johnson County, KS's SSURGO dominant class comes back "Very limited", covering 93.4% of the county. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 93.4% of the county. For scale: 473.629 square miles and 632,276 people call Johnson County home.

Before you rely on this for one lot

Johnson County's rating is an average across the whole county, not a promise about any one lot inside it. The real answer for one lot is still a site-specific perc test, running about $750-$1,850 (typically near $1,300).

Budgeting for a system in Johnson County, KS

Johnson County's soil reading pushes the likely outcome toward an engineered system rather than a conventional one. 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, Johnson County, KS ranks 866 most-constrained nationally, and 41 of 105 within Kansas.

Related guides

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