New Hampshire PFAS results from EPA's final data
Report published Nov 14, 2026 · EPA UCMR 5 final data file of Oct 15, 2026 (samples collected 2023–2025) · Method · National results →
9 New Hampshire water systems serving 222,708 people had PFAS above a 2024 federal limit in EPA's final round of nationwide PFAS testing: 18% of the 49 New Hampshire systems tested, compared with 11% nationally.
Highest PFOA or PFOS averages in New Hampshire
- Hudson Water Dept Hudson · PFOA8 ppt
- Salem Water Dept Salem · PFOA7.45 ppt
- Litchfield Water System Litchfield · PFOA7.45 ppt
- Rye Water District Rye · PFOA6.95 ppt
- Hampstead Area Water Hampstead · PFOA6.25 ppt
- Portsmouth Water Works Portsmouth · PFOA6 ppt
- Jaffrey Water Works Jaffrey · PFOA5.95 ppt
- Manchester Water Works Manchester · PFOA4.5 ppt
- Londonderry Water System Londonderry · PFOA4.2 ppt
- Seabrook Water Dept Seabrook · PFOA4 ppt
- Little Pond Estates Water System Bedford · PFOA3.75 ppt
- Central Hooksett Water Pct Hooksett · PFOA3.47 ppt
- Pembroke Water Works Pembroke · PFOS3.25 ppt
- Derry Water Dept Derry · PFOA3.2 ppt
- Exeter Water Dept Exeter · PFOA2.75 ppt
Chart data as a table
| System | ppt |
|---|---|
| Hudson Water Dept · Hudson · PFOA | 8 |
| Salem Water Dept · Salem · PFOA | 7.45 |
| Litchfield Water System · Litchfield · PFOA | 7.45 |
| Rye Water District · Rye · PFOA | 6.95 |
| Hampstead Area Water · Hampstead · PFOA | 6.25 |
| Portsmouth Water Works · Portsmouth · PFOA | 6 |
| Jaffrey Water Works · Jaffrey · PFOA | 5.95 |
| Manchester Water Works · Manchester · PFOA | 4.5 |
| Londonderry Water System · Londonderry · PFOA | 4.2 |
| Seabrook Water Dept · Seabrook · PFOA | 4 |
| Little Pond Estates Water System · Bedford · PFOA | 3.75 |
| Central Hooksett Water Pct · Hooksett · PFOA | 3.47 |
| Pembroke Water Works · Pembroke · PFOS | 3.25 |
| Derry Water Dept · Derry · PFOA | 3.2 |
| Exeter Water Dept · Exeter · PFOA | 2.75 |
Largest systems above a limit
| # | System | People served |
|---|---|---|
| 1 | Manchester Water Works Manchester Above: PFOA | 123,500 |
| 2 | Portsmouth Water Works Portsmouth Above: PFOA, PFOS | 33,000 |
| 3 | Salem Water Dept Salem Above: PFOA | 21,080 |
| 4 | Hudson Water Dept Hudson Above: PFOA | 16,700 |
| 5 | Hampstead Area Water Hampstead Above: PFOA | 7,153 |
| 6 | Litchfield Water System Litchfield Above: PFOA | 6,920 |
| 7 | Londonderry Water System Londonderry Above: PFOA | 6,255 |
| 8 | Rye Water District Rye Above: PFOA, PFOS | 4,300 |
| 9 | Jaffrey Water Works Jaffrey Above: PFOA | 3,800 |
Which limits were exceeded
| PFAS | Federal limit | Systems above it |
|---|---|---|
| PFOA 222,708 people | 4 ppt | 9 |
| PFOS 37,300 people | 4 ppt | 2 |
| PFHxS | 10 ppt | 0 |
| PFNA | 10 ppt | 0 |
| GenX (HFPO-DA) | 10 ppt | 0 |
| Hazard Index | 1 | 0 |
"–" in the table above means not detected. A system can be above more than one limit. EPA proposed in May 2026 to rescind the PFHxS, PFNA, GenX and Hazard Index limits. That proposal is not final.
New Hampshire has its own PFAS rules. Env-Dw 705.06, Table 705-7. It applies to community and non-transient non-community systems. MCLGs are zero. Details. This report compares results with the federal limits only.
Data and how to cite it
- Download every New Hampshire water system as CSV (PFOA and PFOS averages, systems above a limit, lead, violations).
- EPA's source file: UCMR 5 occurrence data.
Suggested citation:
Tap Water Results, "New Hampshire PFAS results from EPA's final UCMR 5 data" (published Nov 14, 2026, EPA data file of Oct 15, 2026). https://tapwaterresults.com/pfas/new-hampshire/
You're welcome to quote and republish these figures with a link back. Questions from reporters: see contact.
Method
For each system we average each entry point's UCMR 5 results (non-detects count as zero, complete sets of samples only) and compare the highest entry-point average with the 2024 federal limit, using EPA's rounding. This is how EPA compares UCMR 5 results to the limits in its own data summary, and our national counts match EPA's published table within 2% (how we check). Results are monitoring data from 2023–2025, not compliance determinations, and treatment installed since then is not reflected. Full method.
Questions
How many New Hampshire water systems have PFAS above the limit?
9 of the 49 New Hampshire community water systems EPA tested in 2023–2025 (18%) had at least one entry-point average above a 2024 federal PFAS limit. They serve 222,708 people. Nationally the share is 11%.
Are these systems violating the law?
Not yet. Systems have until 2029 to meet the 2024 limits, and EPA has proposed moving the PFOA and PFOS deadline to 2031 and rescinding the other limits. EPA's UCMR 5 results are monitoring data and do not determine compliance.
Which systems were tested?
EPA's UCMR 5 tested every community water system serving more than 3,300 people and a representative sample of smaller ones. Systems that were not tested have no federal result, which is not the same as having no PFAS.
All New Hampshire water systems → · National results → · PFAS results for every state →
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.