Walthall County's SSURGO septic rating

Very limited

Walthall County, MS: USDA's soil survey calls 80.5% of the county "Very limited" for a septic leach field. A standard gravity system routinely fails on ground like this; the same share of the county falls in USDA's worst absorption-field bucket outright. For scale: 403.928 square miles and 13,839 people call Walthall County home.

Before you rely on this for one lot

Walthall County's rating is an average across the whole county, not a promise about any one lot inside it. The real answer for one lot is still a site-specific perc test, running about $750-$1,850 (typically near $1,300).

Budgeting for a system in Walthall County, MS

Walthall County's soil reading pushes the likely outcome toward an engineered system rather than a conventional one. 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.

Where this sits nationally

Among the 3,058 rated counties on this site, Walthall County, MS ranks 2,019 most-constrained nationally, and 70 of 82 within Mississippi.

Related guides

How this rating is built, and its real limits · Conventional vs. engineered septic systems