Septic soil in Beaverhead County, MT, by the numbers

Very limited

Soil across 80.4% of Beaverhead County, MT rates "Very limited" in USDA's septic-absorption-field interpretation. That reading means a conventional system is a poor bet here - 80.4% of Beaverhead County lands in the strictest "very limited" bucket USDA uses. Beaverhead County, MT is 5,542.687 square miles with a population of 10,006.

What Beaverhead County's reading doesn't cover

USDA's survey covers the whole of Beaverhead County, MT at once, not any single address. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Beaverhead County will actually do.

What a system would cost here

With 80.4% of Beaverhead County rating "Very limited", a standard gravity system is not a safe assumption here. 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.

Beaverhead County's rank among Montana counties

Nationally, Beaverhead County, MT is the 2,024-most-constrained of 3,058 rated counties for septic soil. Within Montana alone it ranks 29 of 54.

Before you act on this

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