Fallon County, MT: the USDA septic-suitability picture

Very limited

Fallon County, MT: USDA's soil survey calls 62.3% of the county "Very limited" for a septic leach field. That reading means a conventional system is a poor bet here - 62.3% of Fallon County lands in the strictest "very limited" bucket USDA uses. The county spans 1,620.595 square miles, home to 2,946 people.

What this number does and doesn't tell you

USDA's survey covers the whole of Fallon County, MT at once, not any single address. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.

Fallon County: conventional vs. engineered cost

62.3% of Fallon County carrying a "Very limited" reading changes the realistic budget here. 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.

Fallon County's rank among Montana counties

Among the 3,058 rated counties on this site, Fallon County, MT ranks 2,683 most-constrained nationally, and 53 of 54 within Montana.

Further reading

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