Clay County, GA: the USDA septic-suitability picture
Very limited
USDA puts Clay County, GA at "Very limited" for septic absorption fields, the dominant reading across 55.2% of the county's soil. 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. The county spans 195.404 square miles, home to 2,815 people.
What this number does and doesn't tell you
USDA's survey covers the whole of Clay County, GA at once, not any single address. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Clay County: conventional vs. engineered cost
55.2% of Clay County carrying a "Very limited" reading changes the realistic budget here. 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.
Clay County's rank among Georgia counties
Among the 3,058 rated counties on this site, Clay County, GA ranks 2,820 most-constrained nationally, and 96 of 159 within Georgia.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems