Jefferson County, IA's soil, for a septic absorption field

Very limited

Soil across 99% of Jefferson County, IA rates "Very limited" in USDA's septic-absorption-field interpretation. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 99% of Jefferson County's land. Jefferson County, IA is 435.524 square miles with a population of 15,781.

What Jefferson County's reading doesn't cover

USDA's survey covers the whole of Jefferson County, IA at once, not any single address. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Jefferson County will actually do.

What a system would cost here

With 99% of Jefferson County rating "Very limited", a standard gravity system is not a safe assumption here. 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.

How Jefferson County, IA compares

Nationally, Jefferson County, IA is the 96-most-constrained of 3,058 rated counties for septic soil. Within Iowa alone it ranks 5 of 99.

Before you act on this

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