Septic soil in Iron County, WI, by the numbers
Very limited
92.5% of Iron County, WI's surveyed soil comes back "Very limited" in USDA's own SSURGO data, the county's dominant condition for a septic absorption field. That reading means a conventional system is a poor bet here - 92.5% of Iron County lands in the strictest "very limited" bucket USDA uses. Iron County, WI is 758.214 square miles with a population of 6,235.
What Iron County's reading doesn't cover
Iron County's rating is an average across the whole county, not a promise about any one lot inside it. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Iron County will actually do.
What a system would cost here
With 92.5% of Iron County rating "Very limited", a standard gravity system is not a safe assumption here. 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.
Iron County's rank among Wisconsin counties
Nationally, Iron County, WI is the 982-most-constrained of 3,058 rated counties for septic soil. Within Wisconsin alone it ranks 30 of 72.
Before you act on this
How this rating is built, and its real limits · Conventional vs. engineered septic systems