Hardin County's SSURGO septic rating
Very limited
USDA puts Hardin County, OH at "Very limited" for septic absorption fields, the dominant reading across 99.4% of the county's soil. That reading means a conventional system is a poor bet here - 99.4% of Hardin County lands in the strictest "very limited" bucket USDA uses. The county spans 470.285 square miles, home to 30,402 people.
What this number does and doesn't tell you
Two lots a mile apart in Hardin County can carry different soil, even though they share one countywide rating. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Hardin County: conventional vs. engineered cost
99.4% of Hardin 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.
Hardin County's rank among Ohio counties
Among the 3,058 rated counties on this site, Hardin County, OH ranks 35 most-constrained nationally, and 8 of 87 within Ohio.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems