QC Water Quality Report
1 cities tested · Average grade: A · 897 people served
Live Water Alerts for QC →QC water quality overview
QC's drinking water quality is excellent overall, with an average score of 91.6 out of 100 across 1 cities tested. The median score is 91.6, serving a total population of 897 residents. 100% of cities earned an A or B grade, indicating broadly strong water quality infrastructure across the state. The state predominantly relies on groundwater sources, which are naturally filtered but can be affected by agricultural runoff and naturally occurring minerals.
Issues to watch in QC
Explore contaminants in QC
More contaminants tested in QC
How QC cities scored
Best Cities
Worst Cities
Water quality across QC
Each dot is a city, colored by its water quality grade. Size reflects population served. Click any city to view its full water report.
Browse QC by ZIP code
Look up water quality by ZIP code to find the systems serving your area.
View all QC ZIP codes →Frequently asked questions about QC's water
Is QC's tap water safe to drink?
QC's water quality varies by city. The statewide average grade is A (91.6/100). 100% of cities scored an A or B, while 0% received a D or F. Check your specific city for detailed results.
Which QC cities have the best water quality?
The top-rated cities are Derby (A). These cities scored highest based on violation history, lead levels, PFAS contamination, and regulatory compliance.
Which QC cities have the worst water quality?
The lowest-rated cities are Derby (A). We recommend residents in these areas consider water filtration and review their city's specific contaminant data.