Ravalli County, MT: no USDA soil-survey match

Unrated

This county has no matching soil survey data - too rare a gap to guess at. A local percolation test is the only way to know. Ravalli County, MT covers 2,390.967 square miles and is home to 48,187 people, but the dominant soil here carries no SSURGO absorption-field interpretation to report.

This is a county figure, not a parcel figure

Two lots a mile apart in Ravalli County can carry different soil, even though they share one countywide rating. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Ravalli County.

System cost, conventional vs. engineered

Without a countywide reading for Ravalli County, both cost ranges below are worth knowing before a test, not just one. Nationally, conventional systems run $3,000-$8,000 and engineered alternatives run $10,000-$40,000 - which one applies to a lot in Ravalli County is exactly what a perc test settles.

Further reading

How this rating is built, and its real limits · What to check before buying rural land on septic