Poweshiek County's SSURGO septic rating

Very limited

Poweshiek County, IA's SSURGO dominant class comes back "Very limited", covering 99.4% 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. The county spans 584.932 square miles, home to 18,454 people.

What this number does and doesn't tell you

USDA's survey covers the whole of Poweshiek County, IA 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.

Poweshiek County: conventional vs. engineered cost

99.4% of Poweshiek 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, Poweshiek County, IA ranks 38 most-constrained nationally, and 2 of 99 within Iowa.

Further reading

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