Greenwood County, SC's soil, for a septic absorption field
Somewhat limited
52.7% of Greenwood County, SC's surveyed soil comes back "Somewhat limited" in USDA's own SSURGO data, the county's dominant condition for a septic absorption field. It's a soil condition contractors work around routinely, with a bigger field or added fill, rather than one that forces an engineered system outright. Greenwood County, SC is 455.606 square miles with a population of 70,041.
What Greenwood County's reading doesn't cover
USDA's survey covers the whole of Greenwood County, SC at once, not any single address. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Greenwood County will actually do.
What a system would cost here
With 52.7% of Greenwood County rating "Somewhat 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, Greenwood County, SC is the 2,938-most-constrained of 3,058 rated counties for septic soil. Within South Carolina alone it ranks 42 of 46.
Related guides
How this rating is built, and its real limits · How a percolation test actually works