What Deuel County, SD's soil rates for a septic system
Very limited
In Deuel County, SD, 97.1% of the surveyed land carries a "Very limited" rating for a standard septic drain 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. Deuel County, SD is 622.739 square miles with a population of 4,335.
What Deuel County's reading doesn't cover
Nothing about Deuel County, SD's SSURGO figure applies to a specific address - it's a county-wide average. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Deuel County will actually do.
What a system would cost here
With 97.1% of Deuel County rating "Very limited", a standard gravity system is not a safe assumption here. The engineered-system range, $10,000-$40,000 (mound or aerobic treatment), is the more realistic number to plan around, against $3,000-$8,000 for a conventional system on the rare lot that passes.
How Deuel County, SD compares
Nationally, Deuel County, SD is the 370-most-constrained of 3,058 rated counties for septic soil. Within South Dakota alone it ranks 2 of 66.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems