Septic soil in Coahoma County, MS, by the numbers

Very limited

84.5% of Coahoma 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. That reading means a conventional system is a poor bet here - 84.5% of Coahoma County lands in the strictest "very limited" bucket USDA uses. Coahoma County covers 553.102 square miles and counts 20,105 residents.

This is a county figure, not a parcel figure

Coahoma County's rating is an average across the whole county, not a promise about any one lot inside it. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Coahoma County.

System cost, conventional vs. engineered

Given Coahoma 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.

How Coahoma County, MS compares

Nationally, Coahoma County, MS is the 1,735-most-constrained of 3,058 rated counties for septic soil. Within Mississippi alone it ranks 63 of 82.

Further reading

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