PFAS in Tribal Systems, EPA Region 1 drinking water
EPA's final UCMR 5 data covers 2 public water systems in Tribal Systems, EPA Region 1, serving about 54,132 people. PFAS turned up in 1 of them (50%). 1 averaged above at least one EPA limit at a sampling point, affecting about 22,171 people.
Highest PFOA and PFOS averages among systems serving 1,000 or more: Mashantucket Pequot Water System (5.3 / 0.0 ppt).
Every tested system in Tribal Systems, EPA Region 1
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 |
|---|---|---|---|---|---|
| Mohegan Tribal Utility Authority · Uncasville | 31,961 | - | - | 0 | None found |
| Mashantucket Pequot Water System · Mashantucket | 22,171 | 5.3 | - | 6 | Above limit |
Cite this page
Well & Tap. "PFAS in Tribal Systems, EPA Region 1 drinking water: results for 2 systems." Data: U.S. EPA UCMR 5, final release August 2026. https://wellandtap.com/pfas/tribal-systems-epa-region-1/
Source: EPA UCMR 5 final occurrence data (August 2026); population from EPA SDWIS. Method.