Septic soil in Franklin County, IN, by the numbers

Very limited

Soil across 97.7% of Franklin County, IN rates "Very limited" in USDA's septic-absorption-field interpretation. That reading means a conventional system is a poor bet here - 97.7% of Franklin County lands in the strictest "very limited" bucket USDA uses. Franklin County covers 384.426 square miles and counts 23,136 residents.

This is a county figure, not a parcel figure

Nothing about Franklin County, IN's SSURGO figure applies to a specific address - it's a county-wide average. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Franklin County.

System cost, conventional vs. engineered

Given Franklin County's rating, plan for the engineered-system range rather than the conventional one. The engineered-system range, $10,000-$40,000 (mound or aerobic treatment), is the more realistic number to plan around, against $3,000-$8,000 for a conventional system on the rare lot that passes.

Franklin County's rank among Indiana counties

Nationally, Franklin County, IN is the 290-most-constrained of 3,058 rated counties for septic soil. Within Indiana alone it ranks 23 of 90.

Related guides

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