Polk County, WI's soil, for a septic absorption field

Very limited

Soil across 92.9% of Polk County, WI 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 92.9% of Polk County's land. Polk County covers 914.319 square miles and counts 45,831 residents.

This is a county figure, not a parcel figure

Polk County's rating is an average across the whole county, not a promise about any one lot inside it. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Polk County.

System cost, conventional vs. engineered

Given Polk 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.

How Polk County, WI compares

Nationally, Polk County, WI is the 941-most-constrained of 3,058 rated counties for septic soil. Within Wisconsin alone it ranks 27 of 72.

Before you act on this

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