What Winnebago County, IA's soil rates for a septic system

Very limited

In Winnebago County, IA, 87.7% of the surveyed land carries a "Very limited" rating for a standard septic drain field. Practically, that rules out a simple gravity system for most of the county - 87.7% of it sits in USDA's most-constrained bucket. Winnebago County covers 400.489 square miles and counts 10,383 residents.

This is a county figure, not a parcel figure

Nothing about Winnebago County, IA's SSURGO figure applies to a specific address - it's a county-wide average. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Winnebago County.

System cost, conventional vs. engineered

Given Winnebago 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.

Winnebago County's rank among Iowa counties

Nationally, Winnebago County, IA is the 1,493-most-constrained of 3,058 rated counties for septic soil. Within Iowa alone it ranks 79 of 99.

Further reading

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