Free New Hampshire water report: PFAS & lead levels for every water system, worst-affected cities, and EPA violations. Check your ZIP.
New Hampshire's approximately 1.4 million residents draw their drinking water from a mix of surface water and groundwater, with many smaller communities relying entirely on wells. The state's water supply infrastructure is decentralized – there is no single dominant utility serving the majority of the population. Manchester, the largest city, operates its own surface water system, while towns across the state rely on local wells and small community systems. The New Hampshire Department of Environmental Services (NHDES) oversees drinking water regulation and has been at the forefront of PFAS action in the United States. New Hampshire was among the first states to discover widespread PFAS contamination and among the first to adopt enforceable standards stricter than the federal government's.
New Hampshire holds a grim distinction in PFAS history. Pease Air National Guard Base in Portsmouth was one of the first sites in the United States where PFAS contamination in drinking water was identified and linked to health concerns. Testing at Pease in 2014 revealed PFOS levels in a base drinking water well that far exceeded what was then considered safe. The discovery prompted one of the earliest community health studies focused on PFAS exposure, and the Pease community has been tracked by the CDC's ATSDR ever since.
Beyond military contamination, New Hampshire faced a major industrial PFAS source: Saint-Gobain Performance Plastics in Merrimack. Emissions from the facility contaminated private wells and public water supplies in Merrimack, Bedford, and Litchfield with PFOA and other PFAS compounds. The contamination affected thousands of residents and led to extensive well testing, bottled water distribution, and eventually treatment system installations.
In response, New Hampshire adopted some of the strictest PFAS MCLs in the country – setting limits for PFOA, PFOS, PFHxS, and PFNA that are lower than the EPA's 2024 federal standards. The state set its PFOA MCL at 12 parts per trillion and its PFOS MCL at 15 parts per trillion before the federal government finalized its 4 ppt standards. NHDES continues aggressive monitoring, and our data incorporates state testing results alongside UCMR5 data and utility reports.
New Hampshire punches well above its weight on PFAS regulation. For a small state, it has been a national leader in establishing enforceable standards, conducting widespread testing, and holding polluters accountable. The Pease discovery helped catalyze the national conversation about PFAS in drinking water, and the Saint-Gobain case became a model for understanding industrial air emissions as a pathway for PFAS contamination of groundwater.
Compared to neighboring states, New Hampshire moved faster than Massachusetts and Vermont on PFAS regulation, though all three New England states are now among the more proactive in the country. The key difference is New Hampshire's early exposure – having both a military and an industrial contamination event in close succession forced the state to act before most others were even testing.
The state's reliance on small water systems and private wells creates an ongoing challenge. Large utilities can absorb the cost of treatment upgrades, but small community systems and individual homeowners face a heavier financial burden per capita.
New Hampshire's decentralized water supply means your contamination risk depends heavily on your specific source – municipal system, community well, or private well.
1. Check your water quality using our free lookup tool. We map state and federal monitoring data to your ZIP code, including the extensive NHDES testing results. 2. If PFAS is detected, a reverse osmosis system provides the most reliable removal – over 90% for most PFAS compounds. Granular activated carbon (GAC) filters also reduce PFAS but are less effective against shorter-chain compounds. Our water filter guide compares options by independent test data. 3. Private well owners in the Merrimack Valley, Seacoast region, and areas near any industrial facility should test their water. NHDES offers guidance on testing and in some cases financial assistance. Request a detailed water report for your address for the full picture.
For more on PFAS science, see our PFAS guide.
New Hampshire's PFAS story began at Pease. The former Air Force base, which closed in 1991 and became a tradeport and business park, had a drinking water well – the Haven well – that served thousands of workers and a daycare center on the property. When testing in 2014 revealed PFOS at over 2,000 parts per trillion in the Haven well, it was shut down immediately. The discovery led to a community health assessment and biomonitoring study that found elevated PFAS blood levels in exposed individuals, including children who had attended the daycare.
The Saint-Gobain contamination followed a different pathway. The plastics manufacturing facility in Merrimack used PFOA in its production processes, and PFOA-laden emissions settled on surrounding land and infiltrated groundwater. By 2016, private wells in Merrimack, Bedford, and Litchfield were testing positive for PFAS, and the state ordered Saint-Gobain to provide alternative water supplies. The company installed treatment systems and paid for municipal water line extensions, but the contamination had already spread through a wide area.
These two events – one military, one industrial – made New Hampshire a testing ground for PFAS policy. The state legislature passed laws requiring PFAS testing, funded treatment infrastructure, and empowered NHDES to set MCLs through an administrative process rather than waiting for federal action. The result is a regulatory framework that other states have looked to as a model.
New Hampshire's experience demonstrates that PFAS contamination can come from multiple directions simultaneously, and that early detection and aggressive regulation make a measurable difference in limiting exposure. Check your specific address to see what the data shows for your location.