Delaware Water Quality

Drinking water data for all 3 counties.

Avg Water Score

66.1

State Grade

C

Counties with Data

3

of 3 total

All Delaware Counties

CountyWater Score
New Castle County86.0
Kent County56.8
Sussex County55.6

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Frequently Asked Questions

Which county in Delaware has the best water quality?
New Castle County has the highest water quality score in Delaware at 86.0/100 (Grade: A), based on EPA SDWIS data.
Which county in Delaware has the most water violations?
Sussex County has among the lowest water quality scores in Delaware at 55.6/100. See the individual county page for detailed violation history.
Is the tap water safe to drink in Delaware?
Delaware has an average water quality score of 66.1/100 based on EPA Safe Drinking Water Act compliance data. Individual county scores vary — check your specific county's page for detailed information.
What contaminants are found in Delaware water supplies?
Drinking water quality varies by county and water system. The EPA Safe Drinking Water Information System (SDWIS) tracks violations for contaminants like lead, nitrates, bacteria, and disinfection byproducts. See individual county pages for specific contaminant and violation history.

Data Source

Water quality data sourced from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. Scores reflect compliance history and health-based violation counts.

Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.