PFNA in well water
The county where PFNA is found above the limit most often is Gloucester County, New Jersey: 1% of 1,648 private wells tested, according to NJDEP Private Well Testing Act summaries.
PFNA is a long-chain forever chemical found near industrial sites and firefighting foam. It is linked to immune and developmental effects and high cholesterol. New Hampshire set its own limit in 2019.
- EPA limit
- 10 ng/L (EPA MCL (2024 PFAS rule; proposed for rescission May 2026); New Hampshire MCL is 11 ng/L)
- New Jersey level
- 13 ng/L
- CAS number
- 375-95-1
Check your PFNA number
Type the value from your lab report. It is compared to the EPA limit, the same way the full interpretation does it.
Test your own well for PFNA
Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.
Order the Tap Score well water test kit, from $209Already tested? Upload the report
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Systems that remove PFNA
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Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.
For PFNA
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
For PFNA
Whole-house PFAS carbon system
whole-house, at the point of entry, about $3,000
Granular activated carbon certified to NSF/ANSI 53 for PFOA and PFOS; replace media on schedule.
For PFNA
Aquasana HealthShield whole-house filter
whole-house, at the point of entry, about $2,099
Whole-house carbon system the maker certifies to reduce PFAS (PFOA and PFOS) and VOCs at every tap; a UV option adds bacteria protection.
Rather have it installed and sized for your well? Book a free in-home water test with a licensed local company.
Where pfna is worst, by homeowner tests
Counties ranked by the share of private wells above the state guidance level in tests homeowners sent to the state lab. Shares combine town summaries, weighted by wells tested.
| County | Above state level | Wells tested | Highest |
|---|---|---|---|
| Gloucester County, New Jersey | 1,648 | ||
| Ocean County, New Jersey | 751 | ||
| Passaic County, New Jersey | 931 | ||
| Cape May County, New Jersey | 696 | ||
| Camden County, New Jersey | 601 | ||
| Kent County, Michigan | 1,595 | 120 ng/L | |
| Salem County, New Jersey | 951 | ||
| Bergen County, New Jersey | 530 | ||
| Somerset County, New Jersey | 911 | ||
| Franklin County, Massachusetts | 323 | 11 ng/L | |
| Hunterdon County, New Jersey | 1,905 | ||
| Warren County, New Jersey | 1,080 | ||
| Monmouth County, New Jersey | 677 | ||
| Mercer County, New Jersey | 302 | ||
| Sussex County, New Jersey | 2,246 |
By individual samples
Counties with at least 30 individual samples in public monitoring data, against the EPA limit.
| County | Above EPA limit | Samples | Detected | Median |
|---|---|---|---|---|
| Somerset County, Maine | 580 | 41% | 0 ng/L | |
| Kennebec County, Maine | 450 | 21% | 0 ng/L | |
| Waldo County, Maine | 401 | 13% | 0 ng/L | |
| Lincoln County, Maine | 110 | 24% | 0 ng/L | |
| Penobscot County, Maine | 294 | 12% | 0 ng/L | |
| York County, Maine | 385 | 6% | 0 ng/L | |
| Hillsborough County, New Hampshire | 3,644 | 22% | 0 ng/L | |
| Rockingham County, New Hampshire | 2,095 | 23% | 0 ng/L | |
| Washington County, Maine | 36 | 17% | 0 ng/L | |
| Knox County, Maine | 36 | 11% | 0 ng/L | |
| Hancock County, Maine | 58 | 10% | 0 ng/L | |
| Aroostook County, Maine | 113 | 9% | 0 ng/L | |
| Cumberland County, Maine | 573 | 9% | 0 ng/L | |
| Piscataquis County, Maine | 30 | 7% | 0 ng/L | |
| Strafford County, New Hampshire | 157 | 6% | 0 ng/L |
How to test
Use a state-certified lab and a proper sampling bottle; hardware-store strips cannot measure pfna 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
Analysis: PFAS in private wells: known sources versus routine testing, from the same public records.