Madison County, TN
drinking water quality
100,409 residents · 20 public water systems · 9 ZIP codes
EPA sampled 1 of 20 public water systems here, together serving about 91,111 people. The highest reading was PFOS at 20 ng/L at Jackson Water System. 1 of the sampled system was above a federal limit. Last sampled 5/20/2024.
What was found
| Compound | Highest result | Federal limit | Ratio |
|---|---|---|---|
| PFOS | 20 ng/L | 4 ng/L | 5.0× |
| PFHxS | 16.3 ng/L | 10 ng/L | 1.6× |
Also detected, with no federal limit set: PFBS (3.7 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 Madison County
38301 · 38305 · 38313 · 38355 · 38356 · 38362 · 38366 · 38391 · 38392
Readings are county-level, so every ZIP here shares the figure above. Search your ZIP on the map to see it in context.