Idaho Drinking Water Compliance Records
765 water systems serving 1,568,464 people. 3,194 historical EPA violation records in the Q2 2026 snapshot.
TapScore Compliance-History Grades
A
664
87%
B
60
8%
C
29
4%
D
11
1%
F
1
0%
765
Water Systems
1,568,464
Population Served
3,194
Historical Records
393
Health-Based (All Years)
Systems With the Most Recent EPA Records
MOUNTAIN HOME, CITY OF
14,651 served94 historical records78 recent
D
CAPITOL WATER CORP
9,000 served74 historical records68 recent
D
TERRACE LAKES WATER COMPANY
475 served49 historical records36 recent
D
MOUNTAIN HOME AIR FORCE BASE
7,500 served31 historical records20 recent
C
MISSION CREEK WATER ASSN
263 served42 historical records17 recent
F
DRAKE SUBD
150 served14 historical records10 recent
D
REXBURG CITY OF
40,695 served14 historical records9 recent
C
ST ANTHONY
3,606 served8 historical records7 recent
C
FRUITLAND CITY OF
7,458 served25 historical records7 recent
D
SALMON CITY OF
3,158 served23 historical records7 recent
D
Large Systems With No Recent Records
VEOLIA WATER IDAHO
264,978 served86 historical records
A
MERIDIAN WATER DEPT
147,340 served1 historical record
A
CALDWELL CITY OF
74,000 served204 historical records
A
IDAHO FALLS CITY OF
69,450 served2 historical records
A
COEUR D ALENE CITY OF
54,115 served9 historical records
A
KUNA CITY OF
32,038 served44 historical records
A
MOSCOW WATER DEPT
26,000 served2 historical records
A
POST FALLS CITY OF
20,285 served12 historical records
A
LEWISTON ORCHARDS IRRIGATION DIST
20,000 served2 historical records
A
CHUBBUCK CITY OF
15,842 served1 historical record
A
Largest Water Systems in Idaho
| Water System | Grade | Population | Historical Records |
|---|---|---|---|
| VEOLIA WATER IDAHO | A | 264,978 | 86 |
| MERIDIAN WATER DEPT | A | 147,340 | 1 |
| NAMPA CITY OF | B | 100,200 | 39 |
| CALDWELL CITY OF | A | 74,000 | 204 |
| IDAHO FALLS CITY OF | A | 69,450 | 2 |
| POCATELLO CITY OF | C | 58,231 | 24 |
| TWIN FALLS CITY OF | B | 56,121 | 7 |
| COEUR D ALENE CITY OF | A | 54,115 | 9 |
| REXBURG CITY OF | C | 40,695 | 14 |
| KUNA CITY OF | A | 32,038 | 44 |
| MOSCOW WATER DEPT | A | 26,000 | 2 |
| FALLS WATER COMPANY INC | C | 22,650 | 16 |
| POST FALLS CITY OF | A | 20,285 | 12 |
| LEWISTON ORCHARDS IRRIGATION DIST | A | 20,000 | 2 |
| AMMON CITY OF | C | 17,338 | 19 |
| CHUBBUCK CITY OF | A | 15,842 | 1 |
| LEWISTON CITY OF | B | 15,001 | 1 |
| MOUNTAIN HOME, CITY OF | D | 14,651 | 94 |
| STAR SEWER AND WATER DIST WATER SYSTEM | A | 14,000 | 0 |
| BLACKFOOT CITY OF | B | 13,224 | 2 |
Contaminants in Idaho
Lead in IdahoArsenic in IdahoNitrate in IdahoFluoride in IdahoPFOS in IdahoPFOA in IdahoTHMs in IdahoHAA5 in Idaho
Cities in Idaho
BOISE(40)MERIDIAN(8)NAMPA(43)IDAHO FALLS(26)CALDWELL(22)POCATELLO(14)COEUR D ALENE(12)TWIN FALLS(3)POST FALLS(12)REXBURG(5)LEWISTON(9)MOSCOW(4)KUNA(5)RATHDRUM(26)HAYDEN(13)SANDPOINT(23)AMMON(2)MOUNTAIN HOME(13)CHUBBUCK(3)BLACKFOOT(13)STAR(1)MIDDLETON(6)JEROME(5)EAGLE(17)GARDEN CITY(5)BURLEY(6)BONNERS FERRY(11)HAILEY(4)PAYETTE(2)PRESTON(9)FRUITLAND(2)MOUNTAIN HOME AFB(1)EMMETT(6)RIGBY(11)KELLOGG(2)RUPERT(3)WEISER(1)KIMBERLY(2)SHELLEY(7)COEUR D'ALENE(19)AMERICAN FALLS(3)KETCHUM(10)MCCALL(4)BUHL(3)ST MARIES(5)OROFINO(4)ATHOL(19)ST ANTHONY(2)GOODING(2)DRIGGS(6)SPIRIT LAKE(6)SALMON(5)SUN VALLEY(2)SODA SPRINGS(4)HOMEDALE(2)WALLACE(3)GRANGEVILLE(2)HEYBURN(2)WENDELL(1)IONA(3)SUGAR CITY(3)FILER(1)MONTPELIER(1)BELLEVUE(1)DALTON GARDENS(1)VICTOR(4)PRIEST RIVER(2)PARMA(2)KAMIAH(6)MALAD(1)ABERDEEN(1)NEW PLYMOUTH(2)PINEHURST(2)SAGLE(9)WILDER(1)SHOSHONE(1)COTTONWOOD(3)HAUSER(1)PLUMMER(2)WORLEY(4)NEW MEADOWS(2)MARSING(2)HANSEN(2)OAKLEY(2)BAYVIEW(1)UCON(2)GLENNS FERRY(1)KINGSTON(2)GARDEN VALLEY(8)PAUL(1)MOYIE SPRINGS(2)ARCO(2)ASHTON(1)BLANCHARD(2)HAGERMAN(4)FRANKLIN(2)POTLATCH(3)GRACE(3)GENESEE(1)CHALLIS(2)