Sampson County, NC's soil, for a septic absorption field
Very limited
54.3% of Sampson County, NC's surveyed soil comes back "Very limited" in USDA's own SSURGO data, the county's dominant condition for a septic absorption 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. Sampson County, NC is 945.932 square miles with a population of 60,404.
What Sampson County's reading doesn't cover
Sampson County's rating is an average across the whole county, not a promise about any one lot inside it. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Sampson County will actually do.
What a system would cost here
With 54.3% of Sampson 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.
Sampson County's rank among North Carolina counties
Nationally, Sampson County, NC is the 2,834-most-constrained of 3,058 rated counties for septic soil. Within North Carolina alone it ranks 79 of 97.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems