Septic soil in Windham County, VT, by the numbers

Very limited

86% of Windham County, VT'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 86% of the county. Windham County covers 785.959 square miles and counts 45,627 residents.

This is a county figure, not a parcel figure

Windham 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 Windham County.

System cost, conventional vs. engineered

Given Windham 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.

Windham County's rank among Vermont counties

Nationally, Windham County, VT is the 1,618-most-constrained of 3,058 rated counties for septic soil. Within Vermont alone it ranks 9 of 13.

Before you act on this

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