Delaware County, OH
drinking water quality
237,966 residents · 5 public water systems · 10 ZIP codes
EPA sampled 2 of 5 public water systems here, together serving about 193,895 people. The highest reading was PFOA at 4.2 ng/L at Del-Co Water Company, INC.. 1 of the sampled system was above a federal limit. Last sampled 8/7/2023.
What was found
| Compound | Highest result | Federal limit | Ratio |
|---|---|---|---|
| PFOA | 4.2 ng/L | 4 ng/L | 1.1× |
Also detected, with no federal limit set: lithium (12900 ng/L), PFBA (10.7 ng/L), PFHxA (8.7 ng/L), PFPeA (6.3 ng/L), PFBS (4.3 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 Delaware County
43015 · 43021 · 43032 · 43035 · 43061 · 43065 · 43066 · 43074 · 43082 · 43240
Readings are county-level, so every ZIP here shares the figure above. Search your ZIP on the map to see it in context.