State rankings
Idaho water-system rankings
Lowest-scoring systems in Idaho
Ranked lowest score first. Population shown for context.
1 GARDEN CITY WATER AND SEWER SYSTEM GARDEN CITY, ID · ~12,500 served 31 2 CAPITOL WATER CORP BOISE, ID · ~9,000 served 38 3 FORT HALL FORT HALL, ID · ~2,850 served 85 4 MERIDIAN WATER DEPT MERIDIAN, ID · ~147,340 served 91 5 MOUNTAIN HOME AIR FORCE BASE MOUNTAIN HOME AFB, ID · ~7,500 served 92 6 VEOLIA WATER IDAHO BOISE, ID · ~264,978 served 100 7 NAMPA CITY OF NAMPA, ID · ~100,200 served 100 8 CALDWELL CITY OF CALDWELL, ID · ~74,000 served 100 9 IDAHO FALLS CITY OF IDAHO FALLS, ID · ~69,450 served 100 10 POCATELLO CITY OF POCATELLO, ID · ~58,231 served 100 11 TWIN FALLS CITY OF TWIN FALLS, ID · ~56,121 served 100 12 COEUR D ALENE CITY OF COEUR D ALENE, ID · ~54,115 served 100 13 REXBURG CITY OF REXBURG, ID · ~39,790 served 100 14 KUNA CITY OF KUNA, ID · ~32,038 served 100 15 MOSCOW WATER DEPT MOSCOW, ID · ~26,000 served 100 16 FALLS WATER COMPANY INC IDAHO FALLS, ID · ~22,650 served 100 17 POST FALLS CITY OF POST FALLS, ID · ~20,285 served 100 18 LEWISTON ORCHARDS IRRIGATION DIST LEWISTON, ID · ~20,000 served 100 19 AMMON CITY OF AMMON, ID · ~17,338 served 100 20 CHUBBUCK CITY OF CHUBBUCK, ID · ~15,842 served 100 21 LEWISTON CITY OF LEWISTON, ID · ~15,001 served 100 22 MOUNTAIN HOME, CITY OF MOUNTAIN HOME, ID · ~14,651 served 100 23 STAR SEWER AND WATER DIST WATER SYSTEM STAR, ID · ~14,000 served 100 24 BLACKFOOT CITY OF BLACKFOOT, ID · ~13,224 served 100 25 MIDDLETON CITY OF MIDDLETON, ID · ~13,190 served 100
Highest-scoring large systems in Idaho
Systems serving 10,000+ people with the best scores.
1 VEOLIA WATER IDAHO BOISE, ID · ~264,978 served 100 2 NAMPA CITY OF NAMPA, ID · ~100,200 served 100 3 CALDWELL CITY OF CALDWELL, ID · ~74,000 served 100 4 IDAHO FALLS CITY OF IDAHO FALLS, ID · ~69,450 served 100 5 POCATELLO CITY OF POCATELLO, ID · ~58,231 served 100 6 TWIN FALLS CITY OF TWIN FALLS, ID · ~56,121 served 100 7 COEUR D ALENE CITY OF COEUR D ALENE, ID · ~54,115 served 100 8 REXBURG CITY OF REXBURG, ID · ~39,790 served 100
Scores reflect EPA public records (violations, enforcement, PFAS), are system-level, and can’t account for your home’s plumbing. See the methodology.