States › New Hampshire

New Hampshire Tap Water Quality 2026

EPA drinking water data for 204 cities across New Hampshire — covering lead levels, violation history, and compliance status.

Systems tracked: 167 Cities covered: 204 Updated: 2026 Q2
B

New Hampshire earns a B for overall water quality

204 communities across 10 counties and 167 water systems. 99.5% have no open violations.

Median lead where detected: 22.00 ppb
23.4% of systems report lead as not detected — a state filing convention, not a water quality measure
PFAS tested at 32.4% of communities; 18 above the federal limit
Lead reported for 71.1% of communities
99.5% of communities have no open violations
Water Systems
167
Active community systems
Median Lead Level
22 ppb
147% of EPA action level
Fully Compliant
99.5%
of systems — no active violations
How we grade states Grades are based on actual EPA enforcement data — MCL violations and lead levels measured against the 15 ppb federal action level. We do not use MCLG-based detections, which are aspirational zero-tolerance goals that would make nearly every state look dangerous. Read our full methodology →

Best & Worst Cities in New Hampshire

✓ Cleanest Water
Clarksville
Coos County
No data B
Nashua
Hillsborough County
0.0 ppb A
Concord
Merrimack County
1.0 ppb A
Dover
Strafford County
1.0 ppb A
Merrimack
Hillsborough County
0.0 ppb A
Derry
Rockingham County
0.0 ppb A
⚠ Needs Attention
Windsor
Hillsborough County
46.0 ppb F
New Hampton
Belknap County
23.0 ppb F
Lisbon
Grafton County
21.0 ppb D
Tamworth
Carroll County
23.0 ppb D
Landaff
Grafton County
21.0 ppb D
Bethlehem
Grafton County
21.0 ppb D

Water Quality by County

10 of 10
Sort:
CountySystemsLead LevelViolationsGrade
Rockingham County 38 3.0 ppb 0 B
Grafton County 33 21.0 ppb 0 C
Hillsborough County 28 63.0 ppb 0 B
Merrimack County 26 22.0 ppb 0 B
Coos County 17 30.0 ppb 0 B
Carroll County 15 27.0 ppb 0 C
Cheshire County 14 33.0 ppb 0 B
Strafford County 13 11.0 ppb 0 B
Belknap County 11 28.5 ppb 0 C
Sullivan County 9 16.0 ppb 0 B

About New Hampshire Drinking Water

New Hampshire is served by 167 community water systems covering 204 communities across 10 counties. 99.5% have no open violation on record.

Lead was detected in 111 communities, with a median of 22.00 ppb — 147% of the federal action level. A further 34 reported none detected. That share is a state reporting convention rather than a measure of water quality, so it is stated separately rather than averaged in.

PFAS has been tested at 32.4% of communities here, and 18 are above the limits EPA set in 2024. Coverage matters: states that test more find more, so this figure is not comparable with a state that has tested less.

Frequently Asked Questions

Is New Hampshire tap water safe to drink? ▼
99.5% of communities have no open violation on record. 18 have PFAS above the federal limit set in 2024, which is the main open concern.
Does New Hampshire have a lead problem? ▼
212 water systems report a 90th-percentile lead result at or above the 15 ppb action level. The action level is a treatment trigger, not a legal maximum, and 34 communities report no detection at all.
How complete is the data for New Hampshire? ▼
Lead results are reported for 71.1% of communities and PFAS for 32.4%. Where a figure is missing it is shown as not reported rather than assumed safe.
How does New Hampshire compare with other states? ▼
We do not rank states against each other. Lead reporting completeness ranges from under 20% to 100% depending on the state, so a national ranking would compare filing practice rather than water quality.