Madison County, AR's soil, for a septic absorption field

Very limited

85% of Madison County, AR's surveyed soil comes back "Very limited" in USDA's own SSURGO data, the county's dominant condition for a septic absorption field. Practically, that rules out a simple gravity system for most of the county - 85% of it sits in USDA's most-constrained bucket. Madison County, AR is 834.238 square miles with a population of 17,865.

What Madison County's reading doesn't cover

USDA's survey covers the whole of Madison County, AR 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 Madison County will actually do.

What a system would cost here

With 85% of Madison 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, Madison County, AR is the 1,689-most-constrained of 3,058 rated counties for septic soil. Within Arkansas alone it ranks 64 of 75.

Before you act on this

How this rating is built, and its real limits · Conventional vs. engineered septic systems