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Drinking water / ID

PFAS in Idaho drinking water

61 Idaho public water systems tested under UCMR5. 9 detected at least one PFAS compound; 52 detected none at the reporting thresholds. Values are the highest single result per compound, in ng/L (parts per trillion). The federal limit for PFOA and PFOS is 4 ng/L.

Water systemServesHighest results (ng/L)Reading
CAPITOL WATER CORP

ID4010022

AdaPFNA 51PFOS 9.8 *PFOA 5.9 *PFHxS 5.5above final limit
GARDEN CITY WATER AND SEWER SYSTEM

ID4010066

AdaPFOS 28.2 *PFHxS 25.4PFNA 8.2PFBS 6.7above final limit
MERIDIAN WATER DEPT

ID4010097

AdaPFOS 4.9 *PFHxS 3.8above final limit
COEUR D ALENE CITY OF

ID1280053

KootenaiPFPeA 3.4detected
LEWISTON CITY OF

ID2350014

Nez PercePFBS 5.6PFPeA 4.7PFHxA 4.3detected
MOUNTAIN HOME AIR FORCE BASE

ID4200054

ElmorePFHxA 13PFHxS 10PFPeA 6.7PFBS 4.8detected
PAYETTE CITY OF

ID3380009

PayettePFPeA 4.3PFHxA 3.6detected
RATHDRUM CITY OF

ID1280152

KootenaiPFPeA 8PFHxA 4.2detected
SHELLEY CITY OF

ID6060071

BinghamPFBS 3detected

* exceeds the final federal MCL for that compound. Detections of compounds whose limits EPA proposed to rescind in May 2026 are shown for information.

Systems with no PFAS detected

52 tested systems reported no PFAS above the laboratory reporting limits. Each has its own page with its sampling detail.

A detection at the system level does not tell you what reaches one specific tap: levels vary by entry point, treatment train and plumbing. A certified lab test of your own tap settles it. Testing and treatment options