GenX (HFPO-DA) in Tap Water
GenX (HFPO-DA) is a newer PFAS "forever chemical" introduced as a replacement for PFOA. It is now federally regulated both on its own and as part of a PFAS hazard index.
Fluoropolymer manufacturing discharge; persistent and mobile in water.
- 1Fluoropolymer / chemical manufacturing discharge
Most affected: Infants, pregnant people, and immunocompromised individuals.
A result is read with its context
UCMR5 monitored a broad list of PFAS nationally, but PurityMap’s current dataset ingests per-system occurrence only for PFOA, PFOS, and PFHxS. PurityMap does not yet publish a per-system measured value for GenX (HFPO-DA); this page is a reference explainer. To learn what is in your own water, check your utility’s Consumer Confidence Report (CCR) or use a certified home test.
- Above reference
- Evidence exceeds a reference level.
- Detected
- This substance was found in the monitoring record. Being present is not the same as being above a reference level, and this signal does not say which.
- Not detected
- Somebody looked and the laboratory reported nothing above its reporting limit. This is a result, and it is not the same as nobody looking.
- Not monitored
- No sampling for this substance has been reported for this system. Nothing is known either way, and an empty row is not a clean one.
8 cities above the federal limit, of 24 with a detection
- Laurens County W S Comm (sc3020001)SC · 2023-12-17 to 2025-08-26 · EPA UCMR 595.8 ng/LAbove referenceView city →
- GreenwoodSC · 2025-03-04 to 2025-12-03 · EPA UCMR 591.1 ng/LAbove referenceView city →
- Robeson CountyNC · 2023-02-14 to 2023-07-25 · EPA UCMR 534 ng/LAbove referenceView city →
- Big Sandy DistrictKY · 2023-12-14 to 2024-09-25 · EPA UCMR 525 ng/LAbove referenceView city →
- Perth AmboyNJ · 2024-04-08 to 2025-01-31 · EPA UCMR 514 ng/LAbove referenceView city →
- CayceSC · 2025-02-24 to 2025-12-10 · EPA UCMR 511.6 ng/LAbove referenceView city →
- Newberry City (sc3610001)SC · 2023-03-21 to 2024-01-04 · EPA UCMR 510.2 ng/LAbove referenceView city →
- Joint Muni (sc3220003)SC · 2023-11-15 to 2024-08-12 · EPA UCMR 510.1 ng/LAbove referenceView city →
- Newberry W Sa (sc3620002)SC · 2024-04-24 to 2024-10-21 · EPA UCMR 59.7 ng/LView city →
- West ColumbiaSC · 2024-12-10 to 2025-09-10 · EPA UCMR 59.7 ng/LView city →
- ColumbiaSC · 2024-12-19 to 2025-09-23 · EPA UCMR 59.2 ng/LView city →
- LexingtonSC · 2023-07-18 to 2024-04-15 · EPA UCMR 59.1 ng/LView city →
- Lubeck PsdWV · 2024-03-19 to 2024-06-11 · EPA UCMR 58 ng/LView city →
- Bcwsa East Cooper (sc0820009)SC · 2023-03-13 to 2023-11-29 · EPA UCMR 57.4 ng/LView city →
- Moncks CornerSC · 2023-03-20 to 2024-09-04 · EPA UCMR 57.2 ng/LView city →
- Goose Creek City (sc0810004)SC · 2024-09-19 to 2026-03-16 · EPA UCMR 56.8 ng/LView city →
- IrontonOH · 2024-09-18 to 2025-06-18 · EPA UCMR 56.7 ng/LView city →
- RoanokeVA · 2023-09-11 to 2024-06-11 · EPA UCMR 56 ng/LView city →
- Brunswick CountyNC · 2023-01-12 to 2024-10-30 · EPA UCMR 55.8 ng/LView city →
- FairfieldOH · 2023-03-14 to 2024-09-26 · EPA UCMR 55.7 ng/LView city →
- New OrleansLA · 2023-03-07 to 2025-03-11 · EPA UCMR 55.4 ng/LView city →
- South LyonMI · 2024-08-29 to 2025-02-24 · EPA UCMR 55.4 ng/LView city →
- Pike-GibsonIN · 2023-02-08 to 2023-11-06 · EPA UCMR 55.3 ng/LView city →
- Oak IslandNC · 2023-10-09 to 2025-01-07 · EPA UCMR 55.2 ng/LView city →
Latest published value per city, from EPA UCMR 5. Only detections are listed; cities where it was not detected are not shown. A system-level result, not a measurement of any single home.
+2 more states.
What can carry a GenX (HFPO-DA) reduction claim
- Reverse osmosis
Semi-permeable membrane separation removing dissolved minerals, heavy metals, and persistent fluorinated chemicals down to 0.0001 microns.
- Activated carbon (GAC)
Highly porous adsorption media targeting chlorine, disinfection byproducts, volatile organic compounds, and organic chemicals.
- Anion exchange
Synthetic polyvalent resin beads that exchange unwanted dissolved ionic contaminants for harmless benchmark ions.
Boiling does not remove a dissolved chemical compound and can concentrate it. Many pitcher and refrigerator filters carry no verified claim for a compound like this at all.
A finding establishes the need, the need names the capability, the capability requires a verified certification. No product appears before that sequence completes. Filter Finder →
Frequently asked
Answers cite the same records as the page. How PurityMap analyzes water data
GenX (HFPO-DA) is a newer PFAS "forever chemical" introduced as a replacement for PFOA. It is now federally regulated both on its own and as part of a PFAS hazard index.
The enforceable federal limit is 10 ng/L (MCL); MCLG of 10 ng/L. EPA has proposed rescinding this limit; it applies until a final rule. PurityMap reads every measurement against its stated benchmark and never sets its own.
Fluoropolymer / chemical manufacturing discharge.
GenX is associated in studies with liver, kidney, immune, and developmental effects. It was introduced as a replacement for PFOA, but it is likewise persistent, which is why the EPA regulates it directly and within the PFAS hazard index.
Treatment technologies commonly certified to reduce GenX (HFPO-DA) include Reverse osmosis, Activated carbon (GAC), Anion exchange. Match the exact certified claim to your water before buying. Holding a format is not the same as holding the claim.
In PurityMap's published record, 24 cities have a published GenX (HFPO-DA) value from EPA UCMR 5 monitoring (detections), 8 of them above the federal limit. This is the scope of our record, not a national prevalence estimate.