Idaho tap water quality
771 community water systems serving 1.6 million people.
Data: U.S. EPA · How we read the data · How we check it
PFAS: EPA's 2023–2025 testing. Lead: results from the last five years. 2 more systems have no recent lead results in EPA's database.
Water systems with PFAS above the federal limit
Based on EPA's UCMR 5 results (2023–2025) compared to the April 2024 limits, the way EPA compares them. Systems have until 2029 to comply. Largest first.
- Garden City Water and Sewer System12,500 people · Groundwater · IdahoPFOS above limitAlso: PFHxS above limit · PFAS Hazard Index above limit · PFNA detected
- Capitol Water Corp9,000 people · Groundwater · IdahoPFOA above limitAlso: PFOS above limit · PFNA above limit · PFAS Hazard Index above limit · 3 health-based violations since 2016
Idaho PFAS report: chart, rankings and data to download →
Largest water systems in Idaho
- Veolia Water Idaho264,978 people · Surface water · IdahoLithium above screening level
- Meridian Water Dept152,070 people · Groundwater · IdahoPFOS detectedAlso: PFHxS detected · Lithium above screening level
- City of Nampa100,200 people · Groundwater · IdahoLithium above screening level
- City of Caldwell78,740 people · Groundwater · IdahoLithium above screening level
- City of Idaho Falls69,450 people · Groundwater · IdahoLithium above screening level
- City of Pocatello58,231 people · Groundwater · IdahoNitrate violationAlso: Lithium above screening level
- City of Twin Falls56,121 people · Groundwater · IdahoLithium above screening level
- City of Coeur D Alene54,115 people · Groundwater · IdahoNo PFAS above limits
- City of Rexburg40,695 people · Groundwater · IdahoColiform bacteria violationAlso: Lithium above screening level
- City of Kuna32,038 people · Groundwater · IdahoLithium above screening level
- Moscow Water Dept26,000 people · Groundwater · IdahoNo PFAS above limits
- Falls Water Company Inc22,650 people · Groundwater · IdahoColiform bacteria violationAlso: Lithium above screening level
- City of Post Falls20,285 people · Groundwater · IdahoColiform bacteria violation
- Lewiston Orchards Irrigation District20,000 people · Groundwater · IdahoLithium above screening level
- City of Ammon17,338 people · Groundwater · IdahoLithium above screening level
Idaho cities and towns
- Boise City
- Caldwell
- Coeur d'Alene
- Eagle
- Idaho Falls
- Kuna
- Lewiston
- Meridian
- Moscow
- Nampa
- Pocatello
- Post Falls
- Rexburg
- Twin Falls
Most health-based violations since 2016
- Mission Creek Water Association263 people · Groundwater · IdahoUranium violationsAlso: Gross alpha violations · Coliform bacteria violations
- Clearwater Water District80 people · Groundwater · IdahoHaloacetic acids (HAA5) violation
- Meadow Lark Court LLC45 people · Groundwater · IdahoNitrate violations
- Elk City Water and Sewer Association320 people · Surface water · IdahoTotal trihalomethanes (TTHM) violationAlso: Haloacetic acids (HAA5) violation
- Cedar Springs Community Water130 people · Groundwater · IdahoColiform bacteria violations
- Drake Subdivision150 people · Groundwater · IdahoNitrate violations
- Bia North Idaho Water System490 people · Groundwater · IdahoNot in EPA's PFAS sampleAlso: 24 health-based violations since 2016
- City of Bellevue2,747 people · Groundwater · IdahoNot in EPA's PFAS sampleAlso: 22 health-based violations since 2016
- City of Juliaetta624 people · Surface water · IdahoNitrate violations
- Filer Water Works2,858 people · Groundwater · IdahoArsenic violations
- City of Salmon3,158 people · Surface water · IdahoHaloacetic acids (HAA5) violationsAlso: Total trihalomethanes (TTHM) violations
- Fernan Estates Corporation37 people · Groundwater · IdahoArsenic violationsAlso: Coliform bacteria violation
- Banida Water and Sewer District180 people · Groundwater · IdahoColiform bacteria violations
- Wayside Estates Water System50 people · Groundwater · IdahoColiform bacteria violation
- Aspen Ridge Subdivision204 people · Groundwater · IdahoColiform bacteria violation
All Idaho utilities on this site
Every Idaho system serving 50,000+ people or with PFAS above a federal limit, A to Z. Download all 771 systems as CSV.
- Capitol Water Corp
- City of Caldwell
- City of Coeur D Alene
- City of Idaho Falls
- City of Nampa
- City of Pocatello
- City of Twin Falls
- Garden City Water and Sewer System
- Meridian Water Dept
- Veolia Water Idaho
Questions
Does Idaho tap water have PFAS?
EPA tested 61 community water systems in Idaho for 29 PFAS between 2023 and 2025. 4 had at least one regulated PFAS detected, and 2 had an entry-point average above a 2024 federal limit. Those 2 systems serve about 21,500 people (1% of people on community water in Idaho). Systems have until 2029 to meet the limits.
How many Idaho water systems have violations?
262 systems in Idaho had at least one health-based violation since 2016 (1,162 violations in total). 722 violations are currently listed as unaddressed.
Which Idaho water systems are over the lead action level?
1 system had a lead 90th percentile above the 15 ppb action level in their most recent results from the last five years. Another 2 systems have no lead results in EPA's database from the last five years. Lead depends on each home's pipes, so a test of your own tap is the only way to know your level.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.