TapWaterGuide
Worldwide water safety reference
United States Last reviewed:

Delaware Tap Water Quality

about 200
Community water systems
City reports on this site
3
Tracked contaminants
August 28, 2026
Data reviewed

Check a Delaware ZIP Code

Overview

Northern Delaware drinks a mix of Brandywine and White Clay Creek surface water and Potomac aquifer groundwater, served by Veolia Delaware, Wilmington's city system, and Artesian Water. All the major systems meet federal standards.

Delaware sits in the mid-Atlantic PFAS belt: detections near the New Castle Air National Guard Base and in scattered wells pushed the state to set its own PFAS limits ahead of federal rules and fund treatment. Nitrate in southern Sussex County groundwater, driven by intensive poultry agriculture, is the other recurring concern.

Common Contaminants in Delaware

PFAS

Groundwater near New Castle ANG Base and several industrial sites shows PFAS; affected wells are treated or offline and statewide sampling is ongoing

Nitrate

Poultry-farming regions of Sussex County show elevated nitrate in shallow groundwater and private wells

Disinfection byproducts

Surface-water systems in the north manage seasonal trihalomethane levels within limits

Violations & Compliance

Health-based violations are uncommon; Delaware's small size and consolidation into three main utilities keeps oversight tight. PFAS remediation and private-well nitrate are managed as state programs rather than as system violations.

City Reports for Delaware

We haven't published individual city water reports for Delaware 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.