Smyth County, VA's soil, for a septic absorption field

Very limited

77.9% of Smyth County, VA's surveyed soil comes back "Very limited" in USDA's own SSURGO data, the county's dominant condition for a septic absorption field. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 77.9% of the county. Smyth County covers 451.439 square miles and counts 29,137 residents.

This is a county figure, not a parcel figure

Nothing about Smyth County, VA's SSURGO figure applies to a specific address - it's a county-wide average. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Smyth County.

System cost, conventional vs. engineered

Given Smyth 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, Smyth County, VA is the 2,142-most-constrained of 3,058 rated counties for septic soil. Within Virginia alone it ranks 48 of 110.

Before you act on this

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