Lyon County, IA's soil, for a septic absorption field

Very limited

In Lyon County, IA, 96.7% of the surveyed land carries a "Very limited" rating for a standard septic drain field. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 96.7% of Lyon County's land. Lyon County covers 587.609 square miles and counts 12,378 residents.

This is a county figure, not a parcel figure

Lyon 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 Lyon County.

System cost, conventional vs. engineered

Given Lyon 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.

Where this sits nationally

Nationally, Lyon County, IA is the 420-most-constrained of 3,058 rated counties for septic soil. Within Iowa alone it ranks 31 of 99.

Related guides

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