Clermont County, OH: the USDA septic-suitability picture
Very limited
Clermont County, OH's SSURGO dominant class comes back "Very limited", covering 92% of the county. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 92% of the county. The county spans 452.56 square miles, home to 214,123 people.
What this number does and doesn't tell you
USDA's survey covers the whole of Clermont County, OH 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.
Clermont County: conventional vs. engineered cost
92% of Clermont 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.
Where this sits nationally
Among the 3,058 rated counties on this site, Clermont County, OH ranks 1,036 most-constrained nationally, and 70 of 87 within Ohio.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems