What Harding County, SD's soil rates for a septic system
Very limited
In Harding County, SD, 87.4% of the surveyed land carries a "Very limited" rating for a standard septic drain field. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 87.4% of the county. Harding County, SD is 2,671.57 square miles with a population of 1,325.
What Harding County's reading doesn't cover
Nothing about Harding 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 Harding County will actually do.
What a system would cost here
With 87.4% of Harding 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.
Where this sits nationally
Nationally, Harding County, SD is the 1,521-most-constrained of 3,058 rated counties for septic soil. Within South Dakota alone it ranks 37 of 66.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems