One board, local inspectors
Every master and journeyman credential in North Dakota comes from the State Plumbing Board, which also adopts the plumbing code for the whole state, so a license earned in Williston is good in Wahpeton. Fargo, Bismarck, Grand Forks, Minot and other larger cities still run their own permit and inspection desks, while in many small towns the board's own inspectors cover the work. The board's online lookup confirms a plumber's standing, and the city where you live decides whether a separate inspection fee lands on the invoice.
Rivers, aquifers and long winters
Fargo softens water drawn from the Red and Sheyenne rivers, Grand Forks treats Red River and Red Lake River water, and Bismarck and Mandan rely on the Missouri. Minot blends local wells with Missouri River water piped from Lake Sakakawea through the Northwest Area Water Supply project, and much of the rural west runs on mineral-heavy groundwater where softeners are standard. Basements shelter most heaters from the cold, but sidewall vents bury in snowdrifts and January inlet water in the 30s makes undersized tanks run short. In the bigger cities, a thermocouple or valve fix is often a few hundred dollars, while a basement gas tank swap with permit commonly lands between about $1,400 and $3,000; what pushes a Dakota install higher is spelled out under water heater replacement, while frozen-vent shutdowns are covered under no hot water.