Septic soil in Swift County, MN, by the numbers
Very limited
87% of Swift County, MN's surveyed soil comes back "Very limited" in USDA's own SSURGO data, the county's dominant condition for a septic absorption field. Practically, that rules out a simple gravity system for most of the county - 87% of it sits in USDA's most-constrained bucket. Swift County, MN is 742.016 square miles with a population of 9,666.
What Swift County's reading doesn't cover
This is a countywide, area-weighted figure across every soil survey map unit in Swift County, MN - never a reading for one specific parcel. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Swift County will actually do.
What a system would cost here
With 87% of Swift 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.
How Swift County, MN compares
Nationally, Swift County, MN is the 1,544-most-constrained of 3,058 rated counties for septic soil. Within Minnesota alone it ranks 60 of 86.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems