TapWaterGuide
Worldwide water safety reference
United States Last reviewed:

New Hampshire Tap Water Quality

about 690
Community water systems
City reports on this site
3
Tracked contaminants
August 28, 2026
Data reviewed

Check a New Hampshire ZIP Code

Overview

New Hampshire's public systems, Manchester's Lake Massabesic supply chief among them, are clean and compliant. But nearly half the state drinks from private bedrock wells, and that is where New Hampshire's two signature contaminants live: arsenic and PFAS.

The state's granite bedrock naturally yields arsenic (New Hampshire adopted a 5 ppb standard, twice as strict as EPA's), and the Saint-Gobain plastics plant in Merrimack created one of New England's major PFAS plumes, extending bottled water and treatment to thousands of properties. New Hampshire was among the first states to set enforceable PFAS limits.

Common Contaminants in New Hampshire

Arsenic in bedrock wells

Roughly one in five private wells exceeds the state's strict 5 ppb standard; testing rates remain the public-health gap

PFAS

The Merrimack Saint-Gobain plume plus scattered military/industrial sites; state limits among the nation's first, treatment ongoing

Radon and uranium

Granite geology yields radionuclides in some wells; mitigation is well established

Violations & Compliance

Public systems show strong compliance, with PFAS remediation the active front. The state's focus is private wells, which serve almost half of residents outside any federal rule.

City Reports for New Hampshire

We haven't published individual city water reports for New Hampshire yet. Use the ZIP lookup for a statewide assessment, and check your utility's annual Consumer Confidence Report for local detail.

Frequently Asked Questions

Sources & References

The safety rating and guidance on this page draw on the following sources. See our full methodology.