Jones County's SSURGO septic rating
Very limited
Jones County, IA: USDA's soil survey calls 96% 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: 575.618 square miles and 21,116 people call Jones County home.
Before you rely on this for one lot
Jones County's rating is an average across the whole county, not a promise about any one lot inside it. 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 Jones County, IA
Jones 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 Jones County, IA compares
Among the 3,058 rated counties on this site, Jones County, IA ranks 534 most-constrained nationally, and 40 of 99 within Iowa.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems