Delaware Water Quality Report
Tap water quality data for 5 cities in Delaware, updated 2026.
US average: 100 ppm
4 of 5 cities violation-free
5 cities tested
5 water systems tracked
Cleanest Tap Water in Delaware
Cities with the fewest water quality issues
Bear
232K served
Hockessin
231K served
Rehoboth Beach
110K served
New Castle
107K served
Wilmington
208K served
Most Water Quality Issues in Delaware
Cities with the most violations and concerns
Water Hardness Across Delaware
Not sure what your hardness means? Use our Water Hardness Calculator or find the best hardness test kits.
Delaware Tap Water: What You Need to Know
Delaware has 5 tracked water utilities serving approximately 888K residents. The average water hardness is 96 ppm (5.6 GPG), classified as Moderately Hard — below the national average of 100 ppm. Hardness ranges from 45.2 ppm in Rehoboth Beach to 109 ppm in New Castle.
In the past 3 years, 1 of 5 cities in Delaware have recorded water quality violations, totaling 3 violations (0 health-based). All 5 tested cities have lead levels below the EPA action level of 15 ppb.
Frequently Asked Questions About Delaware Water
Is tap water safe to drink in Delaware?
Most tap water in Delaware meets EPA standards, but 1 cities have recorded violations in the past 3 years (0 health-based). We recommend checking your specific city's report on TapWater.org and considering a home water test.
How hard is the water in Delaware?
Delaware's average water hardness is 96 ppm (5.6 GPG), classified as Moderately Hard. This is below the national average of 100 ppm. Hardness varies significantly by city — use our Water Hardness Calculator to check your specific area.
Which city in Delaware has the cleanest tap water?
Based on EPA violation data, lead testing, and water quality metrics, Bear ranks as having the cleanest tap water in Delaware. It has zero violations in the past 3 years and lead levels well below the EPA action level.
Which city in Delaware has the most water quality issues?
Wilmington currently has the most water quality concerns in Delaware, with 3 violations in the past 3 years. Residents should check their city's detailed water quality report and consider using a certified water filter.
Where does Delaware get its water from?
The majority of Delaware's water systems (40%) use surface water as their primary source. Surface water comes from rivers, lakes, and reservoirs. Each city's specific source can vary — check individual city reports for details.
All 5 Cities
Sorted by population served
Bear
Utility serves 232K
Hockessin
Utility serves 231K
Wilmington
Utility serves 208K
Rehoboth Beach
Utility serves 110K
New Castle
Utility serves 107K