Septic suitability in Malheur County, OR
Very limited
Malheur County, OR: USDA's soil survey calls 78.8% 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 78.8% of Malheur County's land. The county spans 9,887.707 square miles, home to 32,315 people.
What this number does and doesn't tell you
USDA's survey covers the whole of Malheur County, OR 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.
Malheur County: conventional vs. engineered cost
78.8% of Malheur 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.
Where this sits nationally
Among the 3,058 rated counties on this site, Malheur County, OR ranks 2,103 most-constrained nationally, and 32 of 36 within Oregon.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems