Idaho tap water quality
771 active community water systems.
Largest water systems
| Grade | System | People | Health violations (5y) |
|---|
| A | Veolia Water Idaho | 264,978 | 0 |
| A | Meridian Water Dept | 152,070 | 0 |
| A | City of Nampa | 100,200 | 0 |
| A | City of Caldwell | 78,740 | 0 |
| A | City of Idaho Falls | 69,450 | 0 |
| B | City of Pocatello | 58,231 | 1 |
| B | City of Twin Falls | 56,121 | 0 |
| A | City of Coeur D Alene | 54,115 | 0 |
| B | City of Rexburg | 40,695 | 0 |
| A | City of Kuna | 32,038 | 0 |
| A | Moscow Water Dept | 26,000 | 0 |
| C | Falls Water Company Inc | 22,650 | 1 |
| A | City of Post Falls | 20,285 | 0 |
| A | Lewiston Orchards Irrigation Dist | 20,000 | 0 |
| B | City of Ammon | 17,338 | 0 |
| A | City of Chubbuck | 15,842 | 0 |
| B | City of Lewiston | 15,001 | 0 |
| C | City of Mountain Home | 14,651 | 2 |
| A | Star Sewer and Water Dist Water System | 14,000 | 0 |
| C | City of Blackfoot | 13,224 | 2 |
| A | City of Middleton | 13,190 | 0 |
| A | City of Jerome | 13,135 | 0 |
| C | Garden City Water and Sewer System | 12,500 | 0 |
| A | Sandpoint Public Works Dept | 12,284 | 0 |
| A | East Greenacres Irrigation Dist | 11,165 | 0 |
| A | Ross Point Water Dist | 10,473 | 0 |
| A | City of Rathdrum | 10,358 | 0 |
| C | Burley Water Dept | 10,345 | 3 |
| A | Hayden Lake Irrigation Dist | 9,375 | 0 |
| F | Capitol Water Corp | 9,000 | 3 |
| A | Avondale Irrigation Dist | 8,785 | 0 |
| A | University of Idaho | 8,589 | 0 |
| A | City of Payette | 8,127 | 0 |
| A | Hailey Water and Sewer | 8,000 | 0 |
| B | Mountain Home Air Force Base | 7,500 | 0 |
| D | City of Fruitland | 7,458 | 5 |
| A | City of Emmett | 6,700 | 0 |
| A | Central Shoshone County Water Dist | 6,455 | 0 |
| A | Eagle, City of (Western Zone) | 6,108 | 0 |
| A | City of Rupert | 5,796 | 0 |
| A | City of Weiser | 5,630 | 0 |
| D | City of Preston | 5,591 | 3 |
| B | City of Rigby | 5,400 | 1 |
| A | City of Kimberly | 5,359 | 0 |
| A | City of American Falls | 4,863 | 0 |
| B | City of Buhl | 4,518 | 0 |
| D | City of McCall | 4,423 | 12 |
| A | City of Shelley | 4,409 | 0 |
| A | City of St Maries | 4,173 | 0 |
| A | Hillside Service Area | 4,140 | 0 |
Most issues (systems serving 10,000+)
C3 health-based violations in the last 5 years; 2 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
C2 health-based violations in the last 5 years; 147 monitoring/reporting violations; 2 not yet resolved; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
C2 health-based violations in the last 5 years; 88 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
CNo health-based violations in the last 5 years; 1 monitoring/reporting violation; PFOA/PFOS average above the 4 ppt federal limit: PFOS; Other PFAS above 2024 limits (rule proposed for repeal): PFHxS, Hazard Index; Lead 90th percentile below the action level (2023).
C1 health-based violation in the last 5 years; 54 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
B1 health-based violation in the last 5 years; 2 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2026).
BNo health-based violations in the last 5 years; 58 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
BNo health-based violations in the last 5 years; 42 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
BNo health-based violations in the last 5 years; 7 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
BNo health-based violations in the last 5 years; 6 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2026).
ANo health-based violations in the last 5 years; 3 monitoring/reporting violations; 1 not yet resolved; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
ANo health-based violations in the last 5 years; 2 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
ANo health-based violations in the last 5 years; 1 monitoring/reporting violation; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
ANo health-based violations in the last 5 years; 1 monitoring/reporting violation; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2026).
ANo health-based violations in the last 5 years; 1 monitoring/reporting violation; 1 not yet resolved; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
ANo health-based violations in the last 5 years; 1 monitoring/reporting violation; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
ANo health-based violations in the last 5 years; 1 monitoring/reporting violation; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
ANo health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2026).
ANo health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2026).
ANo health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
Cities
AberdeenAhsahkaAlbionAmerican FallsArcoAtholAtlantaAtomic CityBancroftBanksBasaltBellevueBlackfootBlanchardBlissBloomingtonBoiseBonners FerryBovillBuhlBurleyCalderCaldwellCambridgeCareywoodCarmenCastlefordCataldoChallisChesterClark ForkClarkiaCoeur d'AleneCoolinCottonwoodCraigmontCuldesacDaytonDearyDesmetDietrichDingleDonnellyDoverDowneyDriggsDuboisEagleEastportEdenElk CityElk RiverEmmettFairfieldFerdinandFilerFish HavenFort HallFranklinFruitlandGarden CityGarden ValleyGeneseeGeorgetownGoodingGraceGrand ViewGrangevilleGreencreekGreenleafHagermanHaileyHammettHarrisonHarvardHaydenHazeltonHeyburnHomedaleHopeHorseshoe BendHoweIdaho CityIdaho FallsIndian ValleyInkomIonaIsland ParkJeromeJuliaettaKamiahKelloggKetchumKimberlyKing HillKooskiaKootenaiKunaLacledeLapwaiLava Hot SpringsLewistonLewisvilleLowmanMalad CityMaltaMarsingMcCallMcCammonMedimontMelbaMeridianMesaMiddletonMidvaleMinidokaMontpelierMooreMoscowMountain HomeMountain Home AfbMoyie SpringsMullanMurtaughNampaNaplesNew MeadowsNew PlymouthNezperceNotusOakleyOldtownOrofinoOsburnParisParmaPayettePeckPicaboPiercePinehurstPlacervillePlummerPocatelloPonderayPost FallsPotlatchPrestonPriest RiverPrincetonRathdrumReubensRexburgRichfieldRigbyRigginsRocklandRupertSagleSaint AnthonySaint MariesSalmonSandpointSantaShelleyShoshoneSilvertonSmeltervilleSoda SpringsSpirit LakeSpringfieldSt. AnthonyStarStitesSugar CitySun ValleySwan ValleySwanlakeTerretonTetonTetoniaTroyTwin FallsUconVictorViolaWallaceWeippeWeiserWendellWestonWhite BirdWilderWorleyYellow Pine