PFAS in Idaho drinking water
EPA's final UCMR 5 data covers 61 public water systems in Idaho, serving about 1.3 million people. PFAS turned up in 9 of them (15%). 2 averaged above at least one EPA limit at a sampling point, affecting about 21,500 people.
Highest PFOA and PFOS averages among systems serving 1,000 or more: Garden City Water and Sewer System (0.0 / 25.5 ppt) and Capitol Water Corp (5.8 / 9.4 ppt).
Every tested system in Idaho
Largest first. PFOA and PFOS columns show the average at each system's worst sampling point; EPA's limit for each is 4 ppt. Filter by name:
| Water system | People | PFOA | PFOS | PFAS found | Result |
|---|---|---|---|---|---|
| Veolia Water · Boise | 264,978 | - | - | 0 | None found |
| Meridian Water Dept · Meridian | 147,340 | - | 2.4 | 2 | Sample at limit |
| City of Nampa · Nampa | 100,200 | - | - | 0 | None found |
| City of Caldwell · Caldwell | 74,000 | - | - | 0 | None found |
| City of Idaho Falls · Idaho Falls | 69,450 | - | - | 0 | None found |
| City of Pocatello · Pocatello | 58,231 | - | - | 0 | None found |
| City of Twin Falls · Twin Falls | 56,121 | - | - | 0 | None found |
| City of Coeur D Alene · Coeur D Alene | 54,115 | - | - | 1 | Below limits |
| City of Rexburg · Rexburg | 40,695 | - | - | 0 | None found |
| City of Kuna · Kuna | 32,038 | - | - | 0 | None found |
| Moscow Water Dept · Moscow | 26,000 | - | - | 0 | None found |
| Falls Water Company INC · Idaho Falls | 22,650 | - | - | 0 | None found |
| City of Post Falls · Post Falls | 20,285 | - | - | 0 | None found |
| Lewiston Orchards Irrigation Dist · Lewiston | 20,000 | - | - | 0 | None found |
| City of Ammon · Ammon | 17,338 | - | - | 0 | None found |
| City of Chubbuck · Chubbuck | 15,842 | - | - | 0 | None found |
| City of Lewiston · Lewiston | 15,001 | - | - | 3 | Below limits |
| City of Mountain Home · Mountain Home | 14,651 | - | - | 0 | None found |
| Star Sewer and Water Dist Water System · Star | 14,000 | - | - | 0 | None found |
| City of Blackfoot · Blackfoot | 13,224 | - | - | 0 | None found |
| City of Middleton · Middleton | 13,190 | - | - | 0 | None found |
| City of Jerome · Jerome | 13,135 | - | - | 0 | None found |
| Garden City Water and Sewer System · Garden City | 12,500 | - | 25.5 | 7 | Above limit |
| Sandpoint Public Works Dept · Sandpoint | 12,284 | - | - | 0 | None found |
| East Greenacres Irrigation Dist · Post Falls | 11,165 | - | - | 0 | None found |
| City of Rathdrum · Rathdrum | 10,358 | - | - | 2 | Below limits |
| Burley Water Dept · Burley | 10,345 | - | - | 0 | None found |
| Hayden Lake Irrigation Dist · Hayden | 9,375 | - | - | 0 | None found |
| Capitol Water Corp · Boise | 9,000 | 5.8 | 9.4 | 7 | Above limit |
| Ross Point Water Dist · Post Falls | 8,965 | - | - | 0 | None found |
| Avondale Irrigation Dist · Hayden | 8,785 | - | - | 0 | None found |
| University of Idaho · Moscow | 8,589 | - | - | 0 | None found |
| City of Payette · Payette | 8,127 | - | - | 2 | Below limits |
| Hailey Water and Sewer · Hailey | 8,000 | - | - | 0 | None found |
| Mountain Home Air Force Base · Mountain Home Afb | 7,500 | - | - | 4 | Sample at limit |
| City of Fruitland · Fruitland | 7,458 | - | - | 0 | None found |
| City of Emmett · Emmett | 6,700 | - | - | 0 | None found |
| Eagle, City of (western Zone) · Eagle | 6,108 | - | - | 0 | None found |
| Central Shoshone County Water Dist · Kellogg | 6,098 | - | - | 0 | None found |
| City of Rupert · Rupert | 5,796 | - | - | 0 | None found |
| City of Weiser · Weiser | 5,630 | - | - | 0 | None found |
| City of Preston · Preston | 5,591 | - | - | 0 | None found |
| City of Rigby · Rigby | 5,400 | - | - | 0 | None found |
| City of American Falls · American Falls | 4,863 | - | - | 0 | None found |
| City of Buhl · Buhl | 4,518 | - | - | 0 | None found |
| City of Mccall · Mccall | 4,423 | - | - | 0 | None found |
| City of Shelley · Shelley | 4,409 | - | - | 1 | Below limits |
| City of Gooding · Gooding | 3,706 | - | - | 0 | None found |
| Eagle, City of (eastern Zone) · Eagle | 3,702 | - | - | 0 | None found |
| St Anthony · St Anthony | 3,606 | - | - | 0 | None found |
| City of Ketchum · Ketchum | 3,555 | - | - | 0 | None found |
| Sun Valley Water and Sewer Dist · Sun Valley | 3,400 | - | - | 0 | None found |
| Grangeville Water Dept · Grangeville | 3,151 | - | - | 0 | None found |
| City of Heyburn · Heyburn | 3,000 | - | - | 0 | None found |
| City of Potlatch · Potlatch | 812 | - | - | 0 | None found |
| Kooskia Water Dept · Kooskia | 607 | - | - | 0 | None found |
| City of Pierce · Pierce | 467 | - | - | 0 | None found |
| Cougar Bay Water Association · Coeur D'alene | 230 | - | - | 0 | None found |
| Kaniksu Shores Estates · Sandpoint | 93 | - | - | 0 | None found |
| Moreland Country Court · Chubbuck | 60 | - | - | 0 | None found |
| Veolia Eagle | - | - | 0 | None found |
On a private well in Idaho?
EPA's program only covers public systems. Private wells are never part of UCMR 5, so the only way to know is to test. Our well testing guide covers which lab tests to order, and the best well water systems covers what to install once you have results.
Cite this page
Well & Tap. "PFAS in Idaho drinking water: results for 61 systems." Data: U.S. EPA UCMR 5, final release August 2026. https://wellandtap.com/pfas/idaho/
Source: EPA UCMR 5 final occurrence data (August 2026); population from EPA SDWIS. Method.