Pondera County, MT's soil, for a septic absorption field

Very limited

81.8% of Pondera County, MT's surveyed soil comes back "Very limited" in USDA's own SSURGO data, the county's dominant condition for a septic absorption field. This is the reading that pushes a project toward an engineered system rather than a conventional one, and it covers 81.8% of Pondera County's land. Pondera County covers 1,624.567 square miles and counts 6,078 residents.

This is a county figure, not a parcel figure

This is a countywide, area-weighted figure across every soil survey map unit in Pondera County, MT - never a reading for one specific parcel. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Pondera County.

System cost, conventional vs. engineered

Given Pondera County's rating, plan for the engineered-system range rather than the conventional one. 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.

How Pondera County, MT compares

Nationally, Pondera County, MT is the 1,947-most-constrained of 3,058 rated counties for septic soil. Within Montana alone it ranks 26 of 54.

Further reading

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