Kidder County, ND: the USDA septic-suitability picture
Very limited
Kidder County, ND's SSURGO dominant class comes back "Very limited", covering 60.8% of the county. A standard gravity system routinely fails on ground like this; the same share of the county falls in USDA's worst absorption-field bucket outright. The county spans 1,351.062 square miles, home to 2,371 people.
What this number does and doesn't tell you
This is a countywide, area-weighted figure across every soil survey map unit in Kidder 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.
Kidder County: conventional vs. engineered cost
60.8% of Kidder 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, Kidder County, ND ranks 2,714 most-constrained nationally, and 36 of 53 within North Dakota.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems