Marion County, MS's soil, for a septic absorption field
Very limited
79.4% of Marion 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 79.4% of Marion County's land. Marion County, MS is 542.326 square miles with a population of 24,008.
What Marion County's reading doesn't cover
Nothing about Marion County, MS's SSURGO figure applies to a specific address - it's a county-wide average. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Marion County will actually do.
What a system would cost here
With 79.4% of Marion 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 Marion County, MS compares
Nationally, Marion County, MS is the 2,071-most-constrained of 3,058 rated counties for septic soil. Within Mississippi alone it ranks 72 of 82.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems