What Treasure County, MT's soil rates for a septic system

Very limited

Soil across 82.9% of Treasure County, MT rates "Very limited" in USDA's septic-absorption-field interpretation. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 82.9% of the county. Treasure County covers 977.801 square miles and counts 739 residents.

This is a county figure, not a parcel figure

USDA's survey covers the whole of Treasure County, MT at once, not any single address. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Treasure County.

System cost, conventional vs. engineered

Given Treasure 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.

Treasure County's rank among Montana counties

Nationally, Treasure County, MT is the 1,873-most-constrained of 3,058 rated counties for septic soil. Within Montana alone it ranks 22 of 54.

Before you act on this

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