Unicoi County, TN
drinking water quality
17,872 residents · 4 public water systems · 3 ZIP codes
EPA sampled 2 of 4 public water systems here, together serving about 16,763 people. The highest reading was PFOS at 6.7 ng/L at Erwin Utilities Authority. 1 of the sampled system was above a federal limit. Last sampled 9/25/2023.
What was found
| Compound | Highest result | Federal limit | Ratio |
|---|---|---|---|
| PFOS | 6.7 ng/L | 4 ng/L | 1.7× |
| PFOA | 4.1 ng/L | 4 ng/L | 1.0× |
| PFHxS | 3.6 ng/L | 10 ng/L | 0.4× |
Also detected, with no federal limit set: lithium (51100 ng/L), PFBS (7.5 ng/L).
What this means
PFAS are industrial chemicals that EPA describes as breaking down only very slowly in the environment. In April 2024 EPA set the first enforceable national limits: 4 ng/L for PFOA and PFOS, 10 ng/L for PFHxS, PFNA and GenX.
These figures are county-level and come from EPA’s sampling of public water systems. They describe the worst result found in the county, not what comes out of any particular tap — that depends on which system serves the address, and on the plumbing in the building. A private well is not covered by this programme at all.
ZIP codes in Unicoi County
37650 · 37657 · 37692
Readings are county-level, so every ZIP here shares the figure above. Search your ZIP on the map to see it in context.