Sanders County's SSURGO septic rating
Very limited
Sanders County, MT: USDA's soil survey calls 86.1% of the county "Very limited" for a septic leach field. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 86.1% of Sanders County's land. The county spans 2,760.4 square miles, home to 13,895 people.
What this number does and doesn't tell you
Nothing about Sanders County, MT's SSURGO figure applies to a specific address - it's a county-wide average. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Sanders County: conventional vs. engineered cost
86.1% of Sanders 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.
How Sanders County, MT compares
Among the 3,058 rated counties on this site, Sanders County, MT ranks 1,613 most-constrained nationally, and 11 of 54 within Montana.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems