Mathews County, VA's soil, for a septic absorption field
Very limited
In Mathews County, VA, 49.6% of the surveyed land carries a "Very limited" rating for a standard septic drain 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. Mathews County covers 85.912 square miles and counts 8,602 residents.
This is a county figure, not a parcel figure
This is a countywide, area-weighted figure across every soil survey map unit in Mathews County, VA - never a reading for one specific parcel. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Mathews County.
System cost, conventional vs. engineered
Given Mathews 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, Mathews County, VA is the 2,889-most-constrained of 3,058 rated counties for septic soil. Within Virginia alone it ranks 96 of 110.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems