Cass County's SSURGO septic rating
Very limited
Cass County, MN's SSURGO dominant class comes back "Very limited", covering 78.2% of the county. That reading means a conventional system is a poor bet here - 78.2% of Cass County lands in the strictest "very limited" bucket USDA uses. The county spans 2,021.484 square miles, home to 31,442 people.
What this number does and doesn't tell you
USDA's survey covers the whole of Cass County, MN at once, not any single address. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Cass County: conventional vs. engineered cost
78.2% of Cass 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, Cass County, MN ranks 2,129 most-constrained nationally, and 77 of 86 within Minnesota.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems