What Marshall County, MS's soil rates for a septic system

Very limited

94.8% of Marshall 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. Practically, that rules out a simple gravity system for most of the county - 94.8% of it sits in USDA's most-constrained bucket. Marshall County, MS is 706.192 square miles with a population of 34,374.

What Marshall County's reading doesn't cover

This is a countywide, area-weighted figure across every soil survey map unit in Marshall County, MS - never a reading for one specific parcel. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Marshall County will actually do.

What a system would cost here

With 94.8% of Marshall 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.

Where this sits nationally

Nationally, Marshall County, MS is the 689-most-constrained of 3,058 rated counties for septic soil. Within Mississippi alone it ranks 26 of 82.

Before you act on this

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