Carter County's SSURGO septic rating
Very limited
USDA puts Carter County, MO at "Very limited" for septic absorption fields, the dominant reading across 73.5% of the county's soil. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 73.5% of Carter County's land. The county spans 507.359 square miles, home to 5,359 people.
What this number does and doesn't tell you
This is a countywide, area-weighted figure across every soil survey map unit in Carter County, MO - never a reading for one specific parcel. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Carter County: conventional vs. engineered cost
73.5% of Carter 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.
Carter County's rank among Missouri counties
Among the 3,058 rated counties on this site, Carter County, MO ranks 2,347 most-constrained nationally, and 107 of 114 within Missouri.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems