Portsmouth, New Hampshire is a picturesque coastal city known for its colonial architecture, craft breweries, and thriving downtown. It’s also home to one of the earliest and most significant PFAS contamination cases in the United States.
The Pease International Tradeport — a redeveloped former Air Force base that now houses businesses, a daycare center, and other facilities — drew its water from the Haven well. In 2014, testing revealed PFOS contamination at approximately 2,100 parts per trillion. At the time, the EPA’s provisional health advisory was 200 ppt. The Haven well was more than 10 times that level.
What followed became one of the first major PFAS exposure studies in the country — and a template for how communities across America would grapple with the same invisible threat.
Pease Air Force Base: The Source
Pease Air Force Base operated from 1956 to 1991 as a Strategic Air Command installation, housing B-47 and B-52 bombers during the Cold War and later serving as a refueling base. During its operational years, the base used AFFF for firefighting training and emergency response, as all military airfields did.
AFFF use occurred at fire training areas, aircraft hangars, and fuel storage facilities on the base. The PFAS from these activities infiltrated the soil and migrated into the groundwater that fed the Haven well.
After the base closed in 1991, the property was converted to the Pease International Tradeport — a mixed-use commercial development. The Haven well continued to supply water to the Tradeport’s businesses and occupants, including a childcare center that served children of workers at the facility.
Nobody was testing for PFAS. The chemicals weren’t regulated, and most people had never heard of them. For 23 years after the base closed, people at the Tradeport — including young children in daycare — drank water contaminated with PFOS at levels now understood to be dangerous.
The Discovery and Shutdown
In 2014, the EPA required testing for unregulated contaminants under the Unregulated Contaminant Monitoring Rule (UCMR 3). PFAS was among the chemicals tested. The results from the Haven well were alarming: PFOS at roughly 2,100 ppt, with other PFAS compounds also detected.
The well was immediately shut down, and the Tradeport was connected to the City of Portsmouth’s water system, which draws from a different source.
But the damage — in terms of exposure — was already done. Workers, visitors, and most critically, children at the Pease childcare center had been consuming this water for years.
The Pease PFAS Health Study
Pease became one of the first sites in the country where a formal PFAS exposure assessment was conducted. The Agency for Toxic Substances and Disease Registry (ATSDR) launched the Pease Study in 2015, offering blood testing to people who had been exposed to the contaminated water.
Key findings:
- Blood serum PFOS levels among Pease-exposed individuals were significantly elevated compared to national averages.
- Children who attended the daycare at Pease had among the highest blood PFOS levels in the study, reflecting both their water consumption and their smaller body size (which concentrates the chemicals).
- PFOS half-life in the human body is estimated at 4-5 years, meaning elevated blood levels persist long after exposure stops.
The Pease Study became part of a larger multi-site PFAS exposure assessment that ATSDR conducted across the country, providing some of the best data available on PFAS blood levels in exposed communities.
The Children at Pease
The most gut-wrenching aspect of the Pease contamination is the childcare center. Young children — infants, toddlers, preschoolers — drank PFAS-contaminated water and had it used to prepare their food during some of the most vulnerable years of their development.
PFAS exposure in early childhood is of particular concern because:
- Developing immune systems may be more susceptible to PFAS-related immune suppression
- Reduced vaccine effectiveness has been documented in PFAS-exposed children
- Thyroid disruption during development can affect growth and cognition
- The long half-life means childhood exposure creates a body burden that persists into adolescence and beyond
Parents who learned about the contamination after the fact faced an agonizing realization: they’d unknowingly sent their children to a facility where the water was poisoning them.
New Hampshire’s Regulatory Response
New Hampshire set some of the strictest PFAS standards in the nation, driven in significant part by the Pease contamination:
- PFOS: 15 ppt MCL
- PFOA: 12 ppt MCL
- PFHxS: 18 ppt MCL
- PFNA: 11 ppt MCL
These standards, established in 2020, are more protective than the EPA’s 2024 federal standards for some compounds. New Hampshire also established an PFAS investigation and remediation fund and required testing of public water systems statewide.
The state’s response was shaped by community advocacy — parents of Pease daycare children, in particular, became vocal advocates for stricter standards and more comprehensive health monitoring.
Current Water Quality in Portsmouth
Portsmouth’s municipal water system, which now serves the Tradeport area, draws from different sources than the Haven well and is not affected by the same contamination. The city monitors for PFAS as required by state and federal regulations.
The Haven well remains offline and is not expected to return to service without extensive treatment infrastructure.
For the broader Portsmouth area, the water quality is generally good. The city’s source water comes from surface water reservoirs in the region, and the treatment process meets all applicable standards.
What Residents Can Do
If you’re on Portsmouth’s municipal water system, the PFAS issue from Pease does not directly affect your current tap water. However, for general water quality protection:
A reverse osmosis system provides the most comprehensive protection against PFAS and other dissolved contaminants.
If you have a private well in the Pease area or near other potential PFAS sources (including the former base boundaries), get it tested. New Hampshire offers PFAS testing resources for private well owners.
If you were exposed — meaning you worked at the Tradeport, your child attended the daycare, or you regularly consumed water from the Haven well before 2014 — blood testing can establish your PFAS body burden. Discuss the results with a healthcare provider familiar with PFAS health effects.
Stay informed about the ongoing cleanup at the former Pease AFB. The Air Force is conducting remedial investigations and cleanup actions under its PFAS response program.
If you’re concerned about your water quality, a certified water treatment professional can test your water and recommend the right system for your home.
A National Wake-Up Call
Pease was one of the first places in America where PFAS contamination became a community crisis — and where the human cost of military chemical use became impossible to ignore. The children at the daycare, the workers who drank the water every day, and the community that rallied for answers all contributed to a national awakening about PFAS.
Today, hundreds of military installations across the country are dealing with the same contamination. Portsmouth was early, and it was severe. The lessons learned here — test proactively, protect children first, and don’t trust the absence of regulation as evidence of safety — apply everywhere.
Sources: ATSDR Pease PFAS exposure assessment, EPA UCMR 3 data, New Hampshire Department of Environmental Services, Air Force Civil Engineer Center PFAS response program, Portsmouth Water Division reports.