Septic soil in Jackson County, AL, by the numbers
Very limited
In Jackson County, AL, 75.3% of the surveyed land carries a "Very limited" rating for a standard septic drain field. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 75.3% of the county. Jackson County, AL is 1,078.014 square miles with a population of 53,780.
What Jackson County's reading doesn't cover
USDA's survey covers the whole of Jackson County, AL 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 Jackson County will actually do.
What a system would cost here
With 75.3% of Jackson 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.
Jackson County's rank among Alabama counties
Nationally, Jackson County, AL is the 2,262-most-constrained of 3,058 rated counties for septic soil. Within Alabama alone it ranks 39 of 67.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems