What Mecosta County, MI's soil rates for a septic system
Very limited
92.1% of Mecosta County, MI'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 - 92.1% of it sits in USDA's most-constrained bucket. Mecosta County, MI is 555.157 square miles with a population of 41,947.
What Mecosta County's reading doesn't cover
Mecosta 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 Mecosta County will actually do.
What a system would cost here
With 92.1% of Mecosta 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 Mecosta County, MI compares
Nationally, Mecosta County, MI is the 1,027-most-constrained of 3,058 rated counties for septic soil. Within Michigan alone it ranks 53 of 83.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems