PFAS in Drinking Water in New Hampshire
What residents of New Hampshire need to know about PFAS ("forever chemicals") in drinking water — including contamination sources, which utilities have documented violations, and how to filter PFAS from tap water.
Source: EPA SDWIS, New Hampshire Department of Environmental Services, CDC · Last reviewed: 2025-01-01
Quick Answer
Is PFAS in drinking water a real concern in New Hampshire?
Yes — New Hampshire is among the most PFAS-affected states in New England. The Saint-Gobain Performance Plastics manufacturing facility in Merrimack, NH caused severe PFAS contamination of the Merrimack area's drinking water supply, affecting both public systems and hundreds of private wells. Pease Air National Guard Base in Portsmouth has also generated documented PFAS contamination.
Where does PFAS come from in New Hampshire?
Saint-Gobain's Merrimack facility — which manufactured PFAS-coated industrial products — discharged PFAS into the air and groundwater for decades, contaminating the Merrimack water supply (which serves approximately 25,000 people) and hundreds of private wells in Merrimack, Bedford, and surrounding towns. Pease ANG Base in Portsmouth contaminated the municipal water supply for the nearby Pease Tradeport community, which serves thousands of workers and some residents.
What should New Hampshire residents know?
Merrimack and surrounding southern New Hampshire communities have dealt with Saint-Gobain PFAS contamination extensively. Merrimack's water utility was one of the first in New England to install treatment for PFAS and to exceed both state and federal health guidelines. New Hampshire set a very protective state MCL of 12 ppt for PFOA and 15 ppt for PFOS in 2019, long before the federal MCL was finalized.
Key Facts
| EPA MCL (PFOA/PFOS) | 4 ppt — effective April 2024 |
| New Hampshire MCL | 12 ppt PFOA, 15 ppt PFOS (2019) — one of first and most protective state standards |
| MCLG | Zero |
| Primary contamination sources | Saint-Gobain Merrimack facility (industrial); Pease ANG Base Portsmouth (AFFF) |
| Merrimack water system | Installed GAC treatment — one of first public utilities in U.S. to treat for PFAS |
| State regulator | New Hampshire Department of Environmental Services |
| Health effects | Cancer (kidney, testicular), thyroid disruption, immune effects, developmental toxicity |
| Effective treatment | GAC (installed at Merrimack) or RO; NH has funded filtration for some affected private wells |
Why PFAS Matters in New Hampshire
New Hampshire's Saint-Gobain contamination is one of the most extensively documented civilian industrial PFAS cases in the country. The company's Merrimack facility emitted PFAS through air deposition and direct discharge into the Merrimack River watershed. Merrimack's water utility detected PFAS far above then-applicable EPA health advisories, installed granular activated carbon treatment, and has been a national case study for industrial PFAS contamination of public water supplies. Pease ANG Base's contamination of Portsmouth-area water — affecting the Newington/Greenland community water system — was documented in 2014 and led to blood testing of residents, discovery of elevated PFAS levels in people, and significant remediation efforts.
Historical Context
Pease ANG Base's PFAS contamination was one of the first major civilian PFAS cases documented in the U.S., with community blood testing in 2014 showing elevated PFAS levels in people who had consumed contaminated water. This early detection made New Hampshire a focal point for PFAS health research and drove the state's aggressive regulatory response.
New Hampshire PFAS Regulation
State MCL — Stricter Than Federal
12 ppt PFOA, 15 ppt PFOS, 11 ppt PFNA, 18 ppt PFHxS — adopted 2019, among the first state PFAS standards in the country.
New Hampshire DES adopted PFAS MCLs in 2019 — among the first states to do so — at 12 ppt PFOA, 15 ppt PFOS, 11 ppt PFNA, and 18 ppt PFHxS. The Saint-Gobain Performance Plastics manufacturing plant in Merrimack contaminated drinking water for tens of thousands of Merrimack area residents; the state required treatment and has pursued aggressive enforcement. New Hampshire's early regulatory action made it a national model for state PFAS programs.
Largest New Hampshire Water Utilities
No PFAS violations on record in EPA SDWIS for New Hampshire utilities in our database. Browse the largest utilities to review their full water quality record.
What Are PFAS (“Forever Chemicals”)?
PFAS are a family of over 12,000 synthetic chemicals used in non-stick cookware, stain-resistant fabrics, food packaging, and AFFF firefighting foam. Their carbon-fluorine bonds do not break down in the environment or the body — hence the name “forever chemicals.” AFFF used at military bases is the single largest source of PFAS in U.S. drinking water.
Full PFAS overview — national data, health effects, all 50 statesWho Should Pay Closest Attention
Merrimack, Bedford, and southern Hillsborough County residents near Saint-Gobain's facility, and Newington/Greenland and Pease Tradeport workers and residents in Rockingham County near Pease ANG, face the highest documented risk. New Hampshire's large private well population — about 40% of the state uses private wells — means many rural residents face unregulated PFAS exposure.
Residents near military bases with AFFF use history
Private well owners near military or industrial sites
Pregnant residents and families with young children
Residents in communities with documented PFAS detections
Anyone who has consumed water above 4 ppt for an extended period
Residents near airports, fire training areas, or industrial manufacturers
How to Check Your Situation in New Hampshire
- 1
Identify your water utility using the ZIP lookup below or by browsing the New Hampshire utility directory on this site.
- 2
Review your utility's Consumer Confidence Report (CCR) — it must report PFAS monitoring results under UCMR5 and the new MCL.
- 3
Check the EPA's ECHO database for your utility's monitoring history. Look for PFAS, PFOA, PFOS, and related compound results.
- 4
Contact your utility directly and ask for their most recent PFAS test results and whether they are implementing treatment under the 2024 MCL.
- 5
If you use a private well near a military base, airport, or industrial facility, order a PFAS panel test from a state-certified laboratory. Tests typically cost $150–$400.
- 6
If PFAS is detected above 4 ppt in your source water, install a certified NSF/ANSI 58 reverse osmosis system or an NSF/ANSI 53-certified activated carbon filter rated for PFAS removal.
How to Remove PFAS from Tap Water
Reverse Osmosis (Best)
90–99% removal — NSF/ANSI 58 certified systems only
Certified Activated Carbon
Effective with NSF/ANSI 53 or 58 certification — verify before buying
Boiling concentrates PFAS. Standard pitcher filters and water softeners do not remove PFAS. Always verify NSF certification before purchasing.
Take Action Now
Look up your New Hampshire utility's PFAS monitoring history on the PFAS Watchlist below.
If your utility has detected PFAS above 4 ppt, install an NSF/ANSI 58-certified reverse osmosis system at your drinking tap.
Private well owners near military or industrial sites should order a PFAS panel test ($150–$400 at a state-certified lab).
Request your utility's most recent Consumer Confidence Report — PFAS results must be disclosed under the new 2024 MCL.
Frequently Asked Questions
Related Pages
PFAS — National Overview
All U.S. utilities with PFAS records
New Hampshire PFAS Watchlist
Live utility PFAS monitoring data
New Hampshire State Overview
All utilities and water quality data
Reverse Osmosis Guide
Removes 90–99% of PFAS
Activated Carbon Filter Guide
NSF/ANSI 53/58 certified options for PFAS
Arsenic in Drinking Water
Another priority contaminant
All Contaminants
Complete reference library
Data Sources & Provenance
All data on this page is sourced from official U.S. government or public datasets.
Find Your Utility
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New Hampshire Department of Environmental Services ↗