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Maryland Tap Water Quality 2026

EPA drinking water data for 421 cities across Maryland — covering lead levels, violation history, and compliance status.

Systems tracked: 166 Cities covered: 421 Updated: 2026 Q2
A

Maryland earns an A for overall water quality

421 communities across 24 counties and 166 water systems. 99.8% have no open violations.

Median lead where detected: 2.74 ppb
63.0% of systems report lead as not detected — a state filing convention, not a water quality measure
PFAS tested at 71.0% of communities; 14 above the federal limit
Lead reported for 94.3% of communities
99.8% of communities have no open violations
Water Systems
166
Active community systems
Median Lead Level
2.74 ppb
18% of EPA action level
Fully Compliant
99.8%
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 Maryland

✓ Cleanest Water
Queen Anne
Prince George's County
0.0 ppb A
Spring Gap
Allegany County
0.0 ppb B
Columbia
Howard County
3.0 ppb A
Germantown
Montgomery County
0.0 ppb A
Waldorf
Charles County
0.0 ppb A
Frederick
Frederick County
1.1 ppb A
⚠ Needs Attention
Westminster
Carroll County
0.0 ppb D
Hampstead
Carroll County
2.0 ppb D
Cecilton
Cecil County
16.0 ppb D
Elkton
Cecil County
0.0 ppb C
Poolesville
Montgomery County
5.0 ppb C
Betterton
Kent County
5.0 ppb C

Water Quality by County

24 of 24
Sort:
CountySystemsLead LevelViolationsGrade
Prince George's County 80 1.5 ppb 0 A
Montgomery County 58 5.0 ppb 0 A
Allegany County 38 1.0 ppb 0 A
Baltimore County 31 2.7 ppb 0 B
Washington County 27 0.8 ppb 0 A
Anne Arundel County 26 6.3 ppb 0 A
Frederick County 25 3.0 ppb 0 A
Harford County 13 2.0 ppb 0 A
Calvert County 13 1.5 ppb 0 A
Garrett County 11 2.2 ppb 0 A

About Maryland Drinking Water

Maryland is served by 166 community water systems covering 421 communities across 24 counties. 99.8% have no open violation on record.

Lead was detected in 147 communities, with a median of 2.74 ppb — 18% of the federal action level. A further 250 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 71.0% of communities here, and 14 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 Maryland tap water safe to drink? ▼
99.8% of communities have no open violation on record. 14 have PFAS above the federal limit set in 2024, which is the main open concern.
Does Maryland have a lead problem? ▼
8 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 250 communities report no detection at all.
How complete is the data for Maryland? ▼
Lead results are reported for 94.3% of communities and PFAS for 71.0%. Where a figure is missing it is shown as not reported rather than assumed safe.
How does Maryland 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.