State Hub
Idaho Water Quality
174
Utilities in database
1.5M
Residents served
40%
On private wells
2
Key contaminants tracked
Drinking Water in Idaho
Idaho has 174 community water systems serving approximately 1.5 million residents. Primary water sources include groundwater. The most commonly reported contaminants include arsenic, nitrates. 40% of Idaho residents rely on private wells. DEQ holds primary enforcement authority under the Safe Drinking Water Act.
Utilities in Idaho
51–75 of 174City of Gooding
ID5240009 · 3,706 served
Eagle, City of (eastern Zone)
ID4010201 · 3,702 served
St Anthony
ID7220067 · 3,606 served
City of Ketchum
ID5070028 · 3,555 served
Rimrock Service Area
ID1280009 · 3,493 served
Sun Valley Water and Sewer Dist
ID5070051 · 3,400 served
City of Bonners Ferry
ID1110003 · 3,367 served
Idoc Sbx Complex
ID4010141 · 3,309 served
City of Salmon
ID7300042 · 3,158 served
Grangeville Water Dept
ID2250023 · 3,151 served
City of Soda Springs
ID6150017 · 3,111 served
City of Heyburn
ID5340006 · 3,000 served
City of Wendell
ID5240028 · 3,000 served
City of Homedale
ID3370012 · 2,999 served
Filer Water Works
ID5420021 · 2,858 served
City of Spirit Lake
ID1280177 · 2,825 served
City of Montpelier
ID6040021 · 2,772 served
City of Bellevue
ID5070004 · 2,747 served
Iona Water Dept
ID7100041 · 2,717 served
Dalton Water Assn Inc
ID1280059 · 2,598 served
City of Orofino
ID2180024 · 2,459 served
Three Mile Water Dist
ID1110028 · 2,458 served
City of Sugar City
ID7330026 · 2,395 served
E Shoshone County Water Dist Wallace
ID1400019 · 2,388 served
City of Victor
ID7410013 · 2,361 served
Key Contaminant Concerns in Idaho
Nitrates
Nitrate (NO₃⁻) is a nitrogen-containing compound that forms naturally through the decomposition of organic matter. At elevated concentrations — almost always from human activity — nitrate interferes with the blood's ability to carry oxygen. The United States produces over 23 million tons of nitrogen fertilizer annually, making agricultural runoff the dominant source of nitrate contamination.
Arsenic
Arsenic (As) occurs naturally in rock and soil, dissolving into groundwater through natural weathering processes. Inorganic arsenic — the form found in drinking water — is a known human carcinogen. The western United States has particularly arsenic-rich geological formations, but elevated levels have been found in 48 states. Arsenic is tasteless and odorless.
Idaho Water FAQs
Quick Links
Data source: Utility data from EPA SDWIS. 174 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-22