Septic suitability in Harmon County, OK
Very limited
Harmon County, OK: USDA's soil survey calls 87.9% of the county "Very limited" for a septic leach field. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 87.9% of the county. The county spans 537.258 square miles, home to 2,315 people.
What this number does and doesn't tell you
This is a countywide, area-weighted figure across every soil survey map unit in Harmon County, OK - never a reading for one specific parcel. Budget $750-$1,850 for a real perc test on any specific parcel - that's the only figure a permit application accepts.
Harmon County: conventional vs. engineered cost
87.9% of Harmon 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.
Harmon County's rank among Oklahoma counties
Among the 3,058 rated counties on this site, Harmon County, OK ranks 1,479 most-constrained nationally, and 24 of 77 within Oklahoma.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems