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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
76–100 of 174Cabinet Mountains Water Dist
ID1110042 · 2,335 served
City of Parma
ID3140089 · 2,250 served
Idoc Idaho State Correctional Center
ID4010240 · 2,204 served
City of Malad
ID6360006 · 2,200 served
City of Driggs
ID7410004 · 2,200 served
City of Priest River
ID1090107 · 2,173 served
City of Aberdeen
ID6060001 · 2,088 served
Twin Lakes Service Area
ID1280099 · 2,023 served
Riverside Water and Sewer District
ID2180032 · 2,000 served
Pinehurst Water Dist
ID1400041 · 1,950 served
City of Wilder
ID3140138 · 1,690 served
City of New Plymouth
ID3380008 · 1,600 served
Hauser Lake Water Assn Inc
ID1280084 · 1,575 served
Oden Water Assn Inc
ID1090092 · 1,524 served
Comore Loma
ID7100020 · 1,500 served
City of Kamiah
ID2310003 · 1,495 served
Shoshone Water Works
ID5320006 · 1,398 served
Bayview Water and Sewer Dist
ID1280014 · 1,320 served
City of Marsing
ID3370013 · 1,300 served
Fairview Water Dist
ID6210006 · 1,300 served
City of Glenns Ferry
ID4200022 · 1,282 served
City of Hansen
ID5420027 · 1,200 served
City of Paul
ID5340014 · 1,195 served
Hayden Pines Grouse Meadows
ID1280257 · 1,188 served
City of Ucon
ID7100094 · 1,161 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
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Data source: Utility data from EPA SDWIS. 174 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-22