Clay County, IL
drinking water quality
12,821 residents · 9 public water systems · 7 ZIP codes
EPA sampled 2 of 9 public water systems here, together serving about 5,775 people. Last sampled 9/12/2023.
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 Clay County
62426 · 62434 · 62824 · 62839 · 62858 · 62879 · 62899
Readings are county-level, so every ZIP here shares the figure above. Search your ZIP on the map to see it in context.