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CheckYourWater

New Hampshire

Merrimack

Good news: No PFAS detected above reporting limits in your water system.

Population served
26K
Systems tested
1
Compounds detected
29
Above federal limits
0

Source: EPA UCMR 5 · Samples collected 2023–2026

What was found in Merrimack’s water

MERRIMACK VILLAGE DIST

Serves 26K people · GW

11Cl-PF3OUdS11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

4:2FTS1H,1H,2H,2H-perfluorohexanesulfonic acid (4:2 FTS)
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

6:2FTS1H,1H,2H,2H-perfluorooctanesulfonic acid (6:2 FTS)
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

8:2FTS1H,1H,2H,2H-perfluorodecanesulfonic acid (8:2 FTS)
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

9Cl-PF3ONS9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

ADONA4,8-dioxa-3H-perfluorononanoic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

HFPO-DAHexafluoropropylene oxide dimer acid
Below federal limit
0EPA limit (10 ppt)2× limit
NEtFOSAAN-ethyl perfluorooctanesulfonamidoacetic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

NFDHANonafluoro-3,6-dioxaheptanoic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

NMeFOSAAN-methyl perfluorooctanesulfonamidoacetic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFBAPerfluorobutanoic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFBSPerfluorobutanesulfonic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFDAPerfluorodecanoic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFDoAPerfluorododecanoic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFEESAPerfluoro (2-ethoxyethane) sulfonic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFHpAPerfluoroheptanoic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFHpSPerfluoroheptanesulfonic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFHxAPerfluorohexanoic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFHxSPerfluorohexanesulfonic acid
Below federal limit
0EPA limit (10 ppt)2× limit
PFMBAPerfluoro(4-methoxybutanoic) acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFMPAPerfluoro-3-methoxypropanoic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFNAPerfluorononanoic acid
Below federal limit
0EPA limit (10 ppt)2× limit
PFOAPerfluorooctanoic acid
Below federal limit
0EPA limit (4.0 ppt)2× limit
PFOSPerfluorooctanesulfonic acid
Below federal limit
0EPA limit (4.0 ppt)2× limit
PFPeAPerfluoropentanoic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFPeSPerfluoropentanesulfonic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFTAPerfluorotetradecanoic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFTrDAPerfluorotridecanoic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

PFUnAPerfluoroundecanoic acid
No federal limit established

This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.

View full system report →

About PFAS contamination in Merrimack

## Summary

Merrimack's municipal water system, served by Merrimack Village District, earned an A grade — the highest possible rating — meaning the system is currently meeting federal drinking water standards for PFAS compounds. No detected concentrations were reported as exceeding any federal limits. While 15 PFAS compounds were screened, none triggered violations under existing federal thresholds. The contamination source tied to Merrimack's long history with PFAS is Saint-Gobain Performance Plastics, a local manufacturer.

## What the data shows

Fifteen PFAS compounds were included in the screening for Merrimack Village District, including HFPO-DA, which carries an EPA limit of 10 parts per trillion. No concentration was reported for HFPO-DA or any other compound on the list, indicating levels were either undetected or below reporting thresholds. The remaining 14 compounds — including PFBS, PFPeA, PFBA, and several others — currently have no established federal limits, meaning they are not subject to enforceable standards regardless of concentration. There is only one water system serving Merrimack, and it received the top grade.

## What residents should know

Merrimack has a well-documented history with PFAS contamination linked to Saint-Gobain Performance Plastics, and a remediation agreement was signed in March 2026 — a development residents should monitor for updates on cleanup timelines and any compensation. The current A grade reflects compliance with today's federal standards, though residents with specific concerns about unregulated compounds should contact Merrimack Village District directly for the most current testing data. Your water utility remains the best source for up-to-date information on what is and isn't being measured.

About this summary: Narrative text on this page was drafted by an AI model (claude-sonnet-4-6) from EPA UCMR 5 data and reviewed before publication. The numeric data above is reported by water utilities directly to the EPA. If you spot an error, email data@checkyourwater.org.

What Merrimack residents can do

Merrimack's water meets federal PFAS standards based on EPA UCMR 5 testing. To stay informed:

  • Read your utility's annual Consumer Confidence Report (CCR) — request a copy if you don't receive one.
  • Sign up for water quality alerts from your utility.
  • If you're on a private well, get it independently tested for PFAS.
  • Reduce PFAS exposure from non-water sources: avoid non-stick cookware, stain-resistant fabrics, and grease-resistant food packaging.

Read the full action guide →

Primary contamination source: Saint-Gobain Performance Plastics

Settlement information: Saint-Gobain remediation deal signed March 2026

How Merrimack compares

Merrimack is part of our launch coverage of communities where EPA UCMR 5 testing has detected PFAS in drinking water.

Where this data comes from

  • Testing program: EPA Unregulated Contaminant Monitoring Rule, 5th cycle (UCMR 5)
  • Testing period: 2023–2026
  • Federal limits: EPA Maximum Contaminant Levels (MCLs) finalized April 2024
  • Methodology: Read how we calculate grades
  • Raw EPA data: EPA UCMR Occurrence Data

This data reflects EPA testing. Your water utility may have more recent results — contact them directly for the most current information.