Lyon County, MN
drinking water quality
25,577 residents · 16 public water systems · 9 ZIP codes
EPA sampled 1 of 16 public water systems here, together serving about 13,890 people. The highest reading was PFHxS at 4.7 ng/L at Marshall. Last sampled 4/8/2024.
What was found
| Compound | Highest result | Federal limit | Ratio |
|---|---|---|---|
| PFHxS | 4.7 ng/L | 10 ng/L | 0.5× |
Also detected, with no federal limit set: lithium (59100 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 Lyon County
56115 · 56132 · 56157 · 56169 · 56175 · 56229 · 56239 · 56258 · 56264
Readings are county-level, so every ZIP here shares the figure above. Search your ZIP on the map to see it in context.