Tama County, IA: the USDA septic-suitability picture

Very limited

Tama County, IA's SSURGO dominant class comes back "Very limited", covering 98.4% of the county. 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. For scale: 721.011 square miles and 16,738 people call Tama County home.

Before you rely on this for one lot

Two lots a mile apart in Tama County can carry different soil, even though they share one countywide rating. The real answer for one lot is still a site-specific perc test, running about $750-$1,850 (typically near $1,300).

Budgeting for a system in Tama County, IA

Tama County's soil reading pushes the likely outcome toward an engineered system rather than a conventional one. 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.

How Tama County, IA compares

Among the 3,058 rated counties on this site, Tama County, IA ranks 191 most-constrained nationally, and 16 of 99 within Iowa.

Further reading

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