Randolph County, AR: the USDA septic-suitability picture
Very limited
Randolph County, AR: USDA's soil survey calls 88.2% 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: 651.913 square miles and 19,040 people call Randolph County home.
Before you rely on this for one lot
USDA's survey covers the whole of Randolph County, AR at once, not any single address. 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 Randolph County, AR
Randolph 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.
How Randolph County, AR compares
Among the 3,058 rated counties on this site, Randolph County, AR ranks 1,450 most-constrained nationally, and 49 of 75 within Arkansas.
Before you act on this
How this rating is built, and its real limits · Conventional vs. engineered septic systems