Septic suitability in Dewey County, SD

Very limited

Dewey County, SD: USDA's soil survey calls 88.9% 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: 2,302.376 square miles and 5,322 people call Dewey County home.

Before you rely on this for one lot

Nothing about Dewey County, SD's SSURGO figure applies to a specific address - it's a county-wide average. 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 Dewey County, SD

Dewey 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, Dewey County, SD ranks 1,385 most-constrained nationally, and 31 of 66 within South Dakota.

Further reading

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