Dunn County's SSURGO septic rating

Very limited

Dunn County, WI's SSURGO dominant class comes back "Very limited", covering 94.7% of the county. Practically, that rules out a simple gravity system for most of the county - 94.7% of it sits in USDA's most-constrained bucket. For scale: 850.16 square miles and 46,135 people call Dunn County home.

Before you rely on this for one lot

Dunn County's rating is an average across the whole county, not a promise about any one lot inside it. 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 Dunn County, WI

Dunn 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.

Where this sits nationally

Among the 3,058 rated counties on this site, Dunn County, WI ranks 695 most-constrained nationally, and 16 of 72 within Wisconsin.

Before you act on this

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