PFOA in well water
PFOA is a forever chemical from firefighting foam, industrial discharge and consumer products. It builds up in the body and is linked to kidney and testicular cancer, high cholesterol, immune effects and low birth weight.
- EPA limit
- 4 ng/L (EPA MCL (2024 PFAS rule); New Hampshire MCL is 12 ng/L)
- CAS number
- 335-67-1
By individual samples
Counties with at least 30 individual samples in public monitoring data, against the EPA limit.
| County | Samples | Detected | Above EPA limit | Median |
|---|---|---|---|---|
| Rockingham County, New Hampshire | 2,124 | 89% | 66% | 7.1 ng/L |
| Hillsborough County, New Hampshire | 3,781 | 96% | 61% | 5.8 ng/L |
| Somerset County, Maine | 576 | 73% | 41% | 2.59 ng/L |
| Kennebec County, Maine | 450 | 65% | 25% | 0.73 ng/L |
| Lincoln County, Maine | 110 | 75% | 23% | 1 ng/L |
| Waldo County, Maine | 401 | 50% | 20% | 0 ng/L |
| Penobscot County, Maine | 294 | 51% | 18% | 0.265 ng/L |
| Knox County, Maine | 36 | 56% | 14% | 0.368 ng/L |
| Washington County, Maine | 36 | 36% | 14% | 0 ng/L |
| Strafford County, New Hampshire | 157 | 54% | 13% | 0.37 ng/L |
| Cumberland County, Maine | 574 | 61% | 12% | 0.447 ng/L |
| Hancock County, Maine | 58 | 53% | 12% | 0.348 ng/L |
| Aroostook County, Maine | 113 | 36% | 12% | 0 ng/L |
| Piscataquis County, Maine | 30 | 40% | 10% | 0 ng/L |
| York County, Maine | 386 | 58% | 9% | 0.347 ng/L |
How to test
Use a state-certified lab and a proper sampling bottle; hardware-store strips cannot measure pfoa at the levels that matter. Collect from the kitchen tap before any treatment, and again after treatment if you install it.
How to treat
- Granular activated carbon whole-house
- Point-of-use reverse osmosis
- Anion exchange