Florence County, SC
drinking water quality
138,049 residents · 24 public water systems · 10 ZIP codes
EPA sampled 3 of 24 public water systems here, together serving about 94,019 people. The highest reading was PFOS at 6.7 ng/L at Florence City Of (SC2110001). 1 of the sampled system was above a federal limit. Last sampled 9/2/2025.
What was found
| Compound | Highest result | Federal limit | Ratio |
|---|---|---|---|
| PFOS | 6.7 ng/L | 4 ng/L | 1.7× |
| PFOA | 5.5 ng/L | 4 ng/L | 1.4× |
Also detected, with no federal limit set: lithium (22600 ng/L), PFHxA (3.8 ng/L), PFPeA (3.8 ng/L), 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 Florence County
29114 · 29161 · 29501 · 29505 · 29506 · 29530 · 29541 · 29555 · 29583 · 29591
Readings are county-level, so every ZIP here shares the figure above. Search your ZIP on the map to see it in context.