States › Delaware

Delaware Tap Water Quality 2026

EPA drinking water data for 70 cities across Delaware — covering lead levels, violation history, and compliance status.

Systems tracked: 42 Cities covered: 70 Updated: 2026 Q2
B

Delaware earns a B for overall water quality

70 communities across 3 counties and 42 water systems. 100.0% have no open violations.

Median lead where detected: 2.00 ppb
40.0% of systems report lead as not detected — a state filing convention, not a water quality measure
PFAS tested at 74.3% of communities; 34 above the federal limit
Lead reported for 100.0% of communities
100.0% of communities have no open violations
Water Systems
42
Active community systems
Median Lead Level
2 ppb
13% of EPA action level
Fully Compliant
100%
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 Delaware

✓ Cleanest Water
Dover
Kent County
2.0 ppb A
New Castle
New Castle County
0.0 ppb A
Clayton
Kent County
0.0 ppb B
Laurel
Sussex County
0.0 ppb A
Long Neck
Sussex County
1.1 ppb A
Highland Acres
Kent County
2.0 ppb A
⚠ Needs Attention
Newark
New Castle County
1.0 ppb D
Frankford
Sussex County
2.0 ppb D
South Bethany
Sussex County
2.0 ppb D
Fenwick Island
Sussex County
2.0 ppb D
Lewes
Sussex County
23.0 ppb D
Bear
New Castle County
1.0 ppb D

Water Quality by County

3 of 3
Sort:
CountySystemsLead LevelViolationsGrade
New Castle County 25 1.0 ppb 0 C
Sussex County 25 2.2 ppb 0 B
Kent County 20 2.0 ppb 0 A

About Delaware Drinking Water

Delaware is served by 42 community water systems covering 70 communities across 3 counties. 100.0% have no open violation on record.

Lead was detected in 42 communities, with a median of 2.00 ppb — 13% of the federal action level. A further 28 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 74.3% of communities here, and 34 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 Delaware tap water safe to drink? ▼
100.0% of communities have no open violation on record. 34 have PFAS above the federal limit set in 2024, which is the main open concern.
Does Delaware have a lead problem? ▼
1 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 28 communities report no detection at all.
How complete is the data for Delaware? ▼
Lead results are reported for 100.0% of communities and PFAS for 74.3%. Where a figure is missing it is shown as not reported rather than assumed safe.
How does Delaware 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.