Johnson County, TN
drinking water quality
18,506 residents · 8 public water systems · 5 ZIP codes
EPA sampled 1 of 8 public water systems here, together serving about 9,304 people. EPA detected 6:2 FTS at 9.5 ng/L. EPA has not set a drinking water limit for 6:2 FTS, so there is no figure to compare it against. Last sampled 9/24/2024.
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 Johnson County
37640 · 37680 · 37683 · 37688 · 37691
Readings are county-level, so every ZIP here shares the figure above. Search your ZIP on the map to see it in context.