Harrison County, IN: the USDA septic-suitability picture
Very limited
USDA puts Harrison County, IN at "Very limited" for septic absorption fields, the dominant reading across 78% 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 484.081 square miles, home to 39,978 people.
What this number does and doesn't tell you
USDA's survey covers the whole of Harrison County, IN 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.
Harrison County: conventional vs. engineered cost
78% of Harrison 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, Harrison County, IN ranks 2,137 most-constrained nationally, and 83 of 90 within Indiana.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems