North Dakota water quality
North Dakota has 409 active public water systems (1,608 on file total), 318 of them graded by TapGraded.
Grade distribution
Biggest water systems
FARGO CITY OF
FARGO, ND · 120,762 served
BISMARCK CITY OF
BISMARCK, ND · 72,417 served
GRAND FORKS REGIONAL WTP
GRAND FORKS, ND · 57,339 served
MINOT CITY OF
MINOT, ND · 48,743 served
WEST FARGO CITY OF
WEST FARGO, ND · 34,858 served
WILLISTON CITY OF
WILLISTON, ND · 26,426 served
DICKINSON CITY OF
DICKINSON, ND · 25,679 served
MANDAN CITY OF
MANDAN, ND · 21,769 served
JAMESTOWN CITY OF
JAMESTOWN, ND · 15,427 served
BELCOURT-TURTLE MTN RURAL WATER SYSTEM
BELCOURT, ND · 13,500 served
Lowest-graded systems
Active, graded systems serving at least 10,000 people, ordered by lowest Tap Grade first.
BELCOURT-TURTLE MTN RURAL WATER SYSTEM
BELCOURT, ND · 13,500 served
MINOT CITY OF
MINOT, ND · 48,743 served
JAMESTOWN CITY OF
JAMESTOWN, ND · 15,427 served
GRAND FORKS REGIONAL WTP
GRAND FORKS, ND · 57,339 served
DICKINSON CITY OF
DICKINSON, ND · 25,679 served
MANDAN CITY OF
MANDAN, ND · 21,769 served
FARGO CITY OF
FARGO, ND · 120,762 served
BISMARCK CITY OF
BISMARCK, ND · 72,417 served
WEST FARGO CITY OF
WEST FARGO, ND · 34,858 served
WILLISTON CITY OF
WILLISTON, ND · 26,426 served
Source: EPA SDWIS/ECHO · Data as of 2026Q2