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
Read the full investigation
PFAS in Merrimack, NH: Saint-Gobain Plant and Community Water ContaminationYears 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.
What was found in Merrimack’s water
MERRIMACK VILLAGE DIST
Serves 26K people · GW
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
This compound is monitored under UCMR 5 but has no enforceable EPA drinking water limit yet.
About PFAS contamination in Merrimack
## Summary
The most recent federal PFAS testing shows no detectable PFAS compounds in the public water supply serving Merrimack, New Hampshire, a result that carries particular weight given the city's well-documented contamination history. Beginning in the mid-2010s, PFOA from the Saint-Gobain Performance Plastics facility was discovered in private wells and detected at concerning levels in several Merrimack Village District public supply wells. Under a consent agreement with the New Hampshire Department of Environmental Services, Saint-Gobain funded the installation of granular activated carbon (GAC) treatment for the municipal system, which has been operating for several years. A separate remediation agreement signed in March 2026 continues Saint-Gobain's work on affected private wells in the surrounding area. Importantly, Merrimack's contamination story has always been centered largely on private wells outside the municipal system, not the public supply itself, and the current testing reflects that distinction.
## What the data shows
The Merrimack Village District (PWSID NH1531010), the public water system serving roughly 25,000 residents, was tested under the EPA's fifth Unregulated Contaminant Monitoring Rule (UCMR 5), which screens for 29 PFAS compounds. Across all samples collected, every one of those 29 compounds came back as non-detect, meaning none were found at or above the EPA's Minimum Reporting Level. No compound approached the federal limit. This is the most thorough federal PFAS screen applied to public water systems to date.
## What residents should know
Customers of the Merrimack Village District can see from this data that their tap water showed no PFAS above the EPA Minimum Reporting Level under current federal testing standards. However, residents on private wells in and around Merrimack should not assume their water shares this result; private wells are not covered by municipal testing, and contamination in the area's private wells has been documented and is the subject of ongoing remediation. If you rely on a private well, contact the New Hampshire Department of Environmental Services or your local health department about testing options. For the most current information on the public supply, contact the Merrimack Village District directly, and consult filter guidance resources if you have remaining concerns about your water.
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 happened next in Merrimack
A running record of how government, utilities, and the community have responded since this data went public.
- Government Action
NH lays out plan to distribute $45 million in PFAS settlement funds
The New Hampshire Department of Environmental Services announced its plan to distribute an initial $45 million in PFAS settlement money across affected public water supplies, with Merrimack expected to be a major recipient.
- Utility Response
Demolition begins at Saint-Gobain Merrimack plant
Saint-Gobain began tearing down its Merrimack facility, the source of decades of PFAS contamination in town wells, while the long-term remediation plan for the site remained undecided.
- Community Action
Merrimack seeks fair share of Saint-Gobain settlement funds
Town leaders publicly pressed the state for a meaningful portion of incoming PFAS settlement money, citing the more than $14.5 million Merrimack Village District has spent on activated carbon treatment for four contaminated wells.
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), and 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.
Primary contamination source: Saint-Gobain Performance Plastics
Settlement information: Saint-Gobain remediation deal signed March 2026
Recent news on Merrimack
- 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.
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.