Septic suitability in Mountrail County, ND
Somewhat limited
USDA puts Mountrail County, ND at "Somewhat limited" for septic absorption fields, the dominant reading across 60.4% of the county's soil. Modification usually rescues a conventional system at this rating - added fill or a larger field - rather than forcing a full engineered redesign. The county spans 1,825.163 square miles, home to 9,474 people.
What this number does and doesn't tell you
This is a countywide, area-weighted figure across every soil survey map unit in Mountrail County, ND - 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.
Mountrail County: conventional vs. engineered cost
60.4% of Mountrail County carrying a "Somewhat 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 Mountrail County, ND compares
Among the 3,058 rated counties on this site, Mountrail County, ND ranks 2,995 most-constrained nationally, and 50 of 53 within North Dakota.
Further reading
How this rating is built, and its real limits · How a percolation test actually works