PFAS Testing Results

New Hampshire

PFAS testing results for 51 water systems serving 729,755 residents.

16 systems exceed federal PFAS limits, affecting 311,929 residents.

Systems tested

35.3% had PFAS detections

Limits exceeded

31.4% of systems

Population affected

312K

served by systems over federal limits

Most common compound

11Cl-PF3OUdS

detected in 18 systems

Grade distribution

Every water system gets a letter grade based on how its worst detected PFAS compound compares to the federal Maximum Contaminant Level. Lower grades mean higher contamination.

A — 33 systems (64.7%)

B — 2 systems (3.9%)

C — 0 systems (0.0%)

D — 16 systems (31.4%)

F — 0 systems (0.0%)

How grades are calculated →

Communities exceeding federal limits

The water systems in New Hampshire where at least one PFAS compound exceeds the EPA Maximum Contaminant Level, sorted worst first.

System name	City	Grade	Worst compound	Times over limit	Population
RYE WATER DIST	RYE	D	PFOA	2.1x	4.3K
HUDSON WATER DEPT	HUDSON	D	PFOA	2.0x	17K
HAMPSTEAD AREA WATER	ATKINSON	D	PFOS	1.9x	7.0K
PEU/LITCHFIELD	NASHUA	D	PFOA	1.9x	7.0K
SEABROOK WATER DEPT	SEABROOK	D	PFOA	1.7x	14K
PEMBROKE WATER WORKS	PEMBROKE	D	PFOS	1.6x	5.2K
SALEM WATER DEPT	SALEM	D	PFOA	1.6x	21K
JAFFREY WATER WORKS	JAFFREY	D	PFOA	1.5x	3.8K
PEU/LONDONDERRY	NASHUA	D	PFOA	1.4x	5.4K
EXETER WATER DEPT	EXETER	D	PFOA	1.4x	12K

Resources for taking action are available in our community toolkit.

What New Hampshire is doing about PFAS

New Hampshire was among the earliest states to adopt enforceable PFAS drinking water standards. In 2019 the New Hampshire Department of Environmental Services finalized MCLs of 12 parts per trillion for PFOA, 15 parts per trillion for PFOS, 18 parts per trillion for PFHxS, and 11 parts per trillion for PFNA. The PFOA, PFHxS, and PFNA values are stricter than the federal EPA MCLs finalized in April 2024, while the PFOS value is weaker than the federal 4 parts per trillion.

The impetus for state action came from contamination in the Merrimack area linked to the Saint-Gobain Performance Plastics facility. Residents led by Laurene Allen pushed successfully for state legislation and a remediation agreement with Saint-Gobain that has funded alternate water supplies for hundreds of homes. Saint-Gobain signed a major remediation deal with the state in early 2026.

The New Hampshire legislature has appropriated funding for PFAS response and testing. State records show NHDES has required all community water systems to sample for PFAS under the state MCL rule and has maintained a publicly accessible results dashboard. The state has also pursued litigation against 3M and DuPont that resulted in settlement payments flowing into a remediation fund.

Public water systems in New Hampshire are subject to both the state MCLs and the federal compliance timeline requiring initial monitoring by 2027 and treatment installation by 2029.

Based on New Hampshire Department of Environmental Services publications and New Hampshire legislative records.

All 51 tested water systems in New Hampshire

Sorted from lowest grade to highest. Click any system name for the full report. Filter by city or name with the search box below.

Showing 50 of 51 systems

Grade	System name	City	Worst compound	vs. EPA limit	Population
D	RYE WATER DIST	RYE	PFOA	2.1× the federal limit	4.3K
D	HUDSON WATER DEPT	HUDSON	PFOA	2.0× the federal limit	17K
D	HAMPSTEAD AREA WATER	ATKINSON	PFOS	1.9× the federal limit	7.0K
D	PEU/LITCHFIELD	NASHUA	PFOA	1.9× the federal limit	7.0K
D	SEABROOK WATER DEPT	SEABROOK	PFOA	1.7× the federal limit	14K
D	PEMBROKE WATER WORKS	PEMBROKE	PFOS	1.6× the federal limit	5.2K
D	SALEM WATER DEPT	SALEM	PFOA	1.6× the federal limit	21K
D	JAFFREY WATER WORKS	JAFFREY	PFOA	1.5× the federal limit	3.8K
D	PEU/LONDONDERRY	NASHUA	PFOA	1.4× the federal limit	5.4K
D	EXETER WATER DEPT	EXETER	PFOA	1.4× the federal limit	12K
D	PORTSMOUTH WATER WORKS	PORTSMOUTH	PFOA	1.4× the federal limit	33K
D	LITTLE POND ESTATES	NASHUA	PFOA	1.3× the federal limit	3.0K
D	AQUARION WATER/NH	MONROE	PFOA	1.2× the federal limit	34K
D	CENTRAL HOOKSETT WATER PCT	HOOKSETT	PFOA	1.2× the federal limit	4.7K
D	MANCHESTER WATER WORKS, NH	MANCHESTER	PFOA	1.1× the federal limit	124K
D	DERRY WATER DEPT	DERRY	PFOA	1.1× the federal limit	17K
B	PEASE TRADE PORT	PORTSMOUTH	PFBA	Below detection	9.9K
B	RAYMOND WATER DEPT	RAYMOND	PFHxA	Below detection	3.3K
A	LOWER BARTLETT WATER PCT	INTERVALE	-	Below detection	3.8K
A	RIVER RUN CONDOS	NORTH CONWAY	-	Below detection	750
A	BERLIN WATER WORKS	BERLIN	-	Below detection	9.6K
A	PENACOOK BOSCAWEN WATER PCT	NASHUA	-	Below detection	3.8K
A	BRISTOL WATER WORKS	BRISTOL	-	Below detection	3.6K
A	UNITED NATURAL FOODS	MINNEAPOLIS	-	Below detection	330
A	CLAREMONT WATER DEPT	CLAREMONT	-	Below detection	9.0K
A	CONCORD WATER DEPT, NH	CONCORD	-	Below detection	44K
A	NORTH CONWAY WATER PCT	NORTH CONWAY	-	Below detection	5.5K
A	SACO RIVER FOREST	FREEDOM	-	Below detection	63
A	DOVER WATER DEPT, NH	DOVER	-	Below detection	29K
A	UNH/DURHAM WATER SYS	DURHAM	-	Below detection	16K
A	FRANKLIN WATER WORKS	FRANKLIN	-	Below detection	7.0K
A	VILLAGE DIST OF EASTMAN	GRANTHAM	-	Below detection	3.4K
A	HANOVER WATER DEPT	HANOVER	-	Below detection	8.5K
A	YANKEE BOOK PEDDLER	IPSWICH	-	Below detection	240
A	KEENE WATER DEPT	KEENE	-	Below detection	30K
A	LACONIA WATER WORKS	LAKEPORT	-	Below detection	21K
A	LEBANON WATER DEPT	LEBANON	-	Below detection	10K
A	LITTLETON WATER AND LIGHT DEPT	LITTLETON	-	Below detection	6.5K
A	VILLAGE DISTRICT OF EIDELWEISS	MADISON	-	Below detection	1.2K
A	MERRIMACK VILLAGE DIST	MERRIMACK	-	Below detection	26K
A	MILFORD WATER UTILITIES DEPT	MILFORD	-	Below detection	9.5K
A	PENNICHUCK WATER WORKS	NASHUA	-	Below detection	89K
A	PWW/FARLEY RD ESTATES	NASHUA	-	Below detection	75
A	NEW LONDON SPRINGFIELD WATER	NEW LONDON	-	Below detection	2.8K
A	NEWMARKET WATER WORKS	NEWMARKET	-	Below detection	5.0K
A	NEWPORT WATER WORKS	NEWPORT	-	Below detection	5.0K
A	PETERBOROUGH WATER WORKS	PETERBOROUGH	-	Below detection	4.5K
A	PLYMOUTH VLG WATER AND SEWER	PLYMOUTH	-	Below detection	6.7K
A	ROCHESTER WATER DEPT	ROCHESTER	-	Below detection	25K
A	SOMERSWORTH WATER WORKS	SOMERSWORTH	-	Below detection	12K

More on PFAS in New Hampshire

Investigations

PFAS in Merrimack, NH: Saint-Gobain Plant and Community Water Contamination
Years of treatment investment have brought the Merrimack Village District's finished water within federal PFAS limits, after Saint-Gobain Performance Plastics contaminated wells across five New Hampshire towns. Here's what that recovery has cost.

Recent PFAS news in New Hampshire

LegalConcord Monitor · March 31, 2026
Saint-Gobain to pay $1.71 million to connect contaminated homes in Londonderry to public water
The New Hampshire attorney general reached an agreement with Saint-Gobain requiring the company to pay $1.71 million toward extending a water main to about 350 homes with PFAS-contaminated wells in Londonderry. The deal is the latest in a long line of settlements tied to PFAS from the company's former Merrimack plant. The town will still carry the long-term cost of maintaining the new water line.
Local CoverageNew Hampshire Public Radio · March 31, 2026
Saint-Gobain agrees to fund PFAS project in Londonderry, but the town faces long-term costs
Residents near the former Saint-Gobain Merrimack plant welcomed news that about 350 homes in Londonderry will finally get clean public water. But town officials warned that the $1.71 million payment only covers construction of the water main. Londonderry will pay to operate and maintain the system for decades to come.
Local CoverageNew Hampshire Public Radio · February 20, 2026
Proposed location for ICE facility in Merrimack sits within PFAS contamination zone
A proposed federal immigration detention center in Merrimack would be built on land inside the groundwater contamination zone from the old Saint-Gobain plant. Local activists say the site's history of PFAS pollution raises questions about drinking water for future detainees and staff. State regulators have not said how the facility would be served with clean water.

City profiles

A
Merrimack
PFAS profile

Check your water system

Enter your zip code to see the PFAS results for the water system that serves your home.

Where this data comes from

EPA Unregulated Contaminant Monitoring Rule, 5th cycle (UCMR 5)
Testing period: 2023 to 2026
Federal limits: EPA Maximum Contaminant Levels finalized April 2024
Read the full methodology