Charles County, MD
drinking water quality
174,478 residents · 172 public water systems · 22 ZIP codes
EPA sampled 6 of 172 public water systems here, together serving about 109,582 people. EPA detected PFPeA at 6 ng/L. EPA has not set a drinking water limit for PFPeA, so there is no figure to compare it against. Last sampled 9/24/2024.
Health-based violations
Separately from PFAS, EPA records 17 health-based violations across 16 of the county’s water systems since 2020, the most recent in 2024. They involved E. coli, haloacetic acids.
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 Charles County
20601 · 20602 · 20603 · 20611 · 20612 · 20616 · 20617 · 20622 · 20625 · 20632 · 20637 · 20640 · 20645 · 20646 · 20658 · 20661 · 20662 · 20664 · 20675 · 20677 · 20693 · 20695
Readings are county-level, so every ZIP here shares the figure above. Search your ZIP on the map to see it in context.