Garfield County, MT: the USDA septic-suitability picture

Very limited

Garfield County, MT: USDA's soil survey calls 65.2% of the county "Very limited" for a septic leach field. Practically, that rules out a simple gravity system for most of the county - 65.2% of it sits in USDA's most-constrained bucket. For scale: 4,676.56 square miles and 1,181 people call Garfield County home.

Before you rely on this for one lot

USDA's survey covers the whole of Garfield County, MT at once, not any single address. The real answer for one lot is still a site-specific perc test, running about $750-$1,850 (typically near $1,300).

Budgeting for a system in Garfield County, MT

Garfield County's soil reading pushes the likely outcome toward an engineered system rather than a conventional one. Conventional systems run $3,000-$8,000 where they pass; where they don't, engineered alternatives (mound or aerobic treatment, whichever the health department requires) run $10,000-$40,000 - budget toward the higher figure until a perc test says otherwise.

Garfield County's rank among Montana counties

Among the 3,058 rated counties on this site, Garfield County, MT ranks 2,606 most-constrained nationally, and 51 of 54 within Montana.

Further reading

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