Why DeSoto County, FL isn't rated here
Unrated
This county has no matching soil survey data - too rare a gap to guess at. A local percolation test is the only way to know. DeSoto County, FL covers 636.695 square miles and is home to 36,744 people, but the dominant soil here carries no SSURGO absorption-field interpretation to report.
What DeSoto County's reading doesn't cover
DeSoto 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 DeSoto County will actually do.
What a system would cost here
With no SSURGO rating to go on, DeSoto County has no county-level steer either way on system cost. Nationally, conventional systems run $3,000-$8,000 and engineered alternatives run $10,000-$40,000 - which one applies to a lot in DeSoto County is exactly what a perc test settles.
Further reading
How this rating is built, and its real limits · What to check before buying rural land on septic