What Pembina County, ND's soil rates for a septic system
Very limited
Soil across 96.6% of Pembina County, ND rates "Very limited" in USDA's septic-absorption-field interpretation. Expect the ground itself to work against a plain gravity system; USDA's strictest bucket alone covers 96.6% of the county. Pembina County, ND is 1,118.535 square miles with a population of 6,588.
What Pembina County's reading doesn't cover
Pembina County's rating is an average across the whole county, not a promise about any one lot inside it. A local percolation test, typically $750-$1,850 (around $1,300 typical), is the only way to know what one lot in Pembina County will actually do.
What a system would cost here
With 96.6% of Pembina County rating "Very limited", a standard gravity system is not a safe assumption here. 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.
Where this sits nationally
Nationally, Pembina County, ND is the 443-most-constrained of 3,058 rated counties for septic soil. Within North Dakota alone it ranks 1 of 53.
Further reading
How this rating is built, and its real limits · Conventional vs. engineered septic systems