Septic suitability in Sherburne County, MN
Very limited
Sherburne County, MN: USDA's soil survey calls 94.4% of the county "Very limited" for a septic leach field. Practically, that rules out a simple gravity system for most of the county - 94.4% of it sits in USDA's most-constrained bucket. The county spans 432.947 square miles, home to 103,059 people.
What this number does and doesn't tell you
Sherburne County's rating is an average across the whole county, not a promise about any one lot inside it. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Sherburne County: conventional vs. engineered cost
94.4% of Sherburne County carrying a "Very limited" reading changes the realistic budget here. Conventional systems run $3,000-$8,000 where they pass; where they don't, engineered alternatives (mound or aerobic treatment, whichever the health department requires) run $10,000-$40,000 - budget toward the higher figure until a perc test says otherwise.
Where this sits nationally
Among the 3,058 rated counties on this site, Sherburne County, MN ranks 722 most-constrained nationally, and 28 of 86 within Minnesota.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems