Corson County's SSURGO septic rating

Very limited

Corson County, SD: USDA's soil survey calls 80.3% of the county "Very limited" for a septic leach field. A standard gravity system routinely fails on ground like this; the same share of the county falls in USDA's worst absorption-field bucket outright. For scale: 2,469.694 square miles and 3,747 people call Corson County home.

Before you rely on this for one lot

USDA's survey covers the whole of Corson County, SD at once, not any single address. 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 Corson County, SD

Corson 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.

How Corson County, SD compares

Among the 3,058 rated counties on this site, Corson County, SD ranks 2,029 most-constrained nationally, and 49 of 66 within South Dakota.

Before you act on this

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