Mobile County, AL: the USDA septic-suitability picture

Very limited

Mobile County, AL: USDA's soil survey calls 69.9% of the county "Very limited" for a septic leach field. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 69.9% of the county. For scale: 1,229.382 square miles and 412,339 people call Mobile County home.

Before you rely on this for one lot

USDA's survey covers the whole of Mobile County, AL 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 Mobile County, AL

Mobile 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.

Mobile County's rank among Alabama counties

Among the 3,058 rated counties on this site, Mobile County, AL ranks 2,463 most-constrained nationally, and 44 of 67 within Alabama.

Related guides

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