Honolulu Tap Water Quality: Is It Safe to Drink? (2026 Report)

Honolulu, Hawaii tap water receives a grade of A (88/100), which is considered excellent. Out of 73 contaminants tested, none exceed EPA maximum contaminant levels (MCLs) and 1 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.

Of the 73 contaminants tested in Honolulu's water supply, the most notable include vanadium. No contaminants exceed EPA legal limits. 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.

Yes, Honolulu has 81 EPA violation(s) on record, with the most recent in 2015. Violation types include MCL, MR. 9 of these are health-based violations, which are the most serious category.

Honolulu water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 1 contaminant(s) exceed these stricter goals.

Honolulu's drinking water is sourced from groundwater and supplied by THE QUEEN'S MEDICAL CENTER and 10 other water system(s). The system serves approximately 961,187 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.

Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Honolulu's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.

Honolulu's water quality score of 88/100 earns a grade of A, which is considered excellent. This places Honolulu among the better-performing water systems in Hawaii. Visit our Hawaii state page to see how all cities in the state compare.

If you have concerns about Honolulu's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (THE QUEEN'S MEDICAL CENTER) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.