Septic soil in Tate County, MS, by the numbers
Very limited
86.3% of Tate County, MS's surveyed soil comes back "Very limited" in USDA's own SSURGO data, the county's dominant condition for a septic absorption field. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 86.3% of Tate County's land. Tate County covers 404.763 square miles and counts 28,551 residents.
This is a county figure, not a parcel figure
This is a countywide, area-weighted figure across every soil survey map unit in Tate County, MS - never a reading for one specific parcel. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Tate County.
System cost, conventional vs. engineered
Given Tate County's rating, plan for the engineered-system range rather than the conventional one. 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.
Where this sits nationally
Nationally, Tate County, MS is the 1,588-most-constrained of 3,058 rated counties for septic soil. Within Mississippi alone it ranks 56 of 82.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems