Honolulu, HI Tap Water Quality

Tap water in Honolulu, HI ranks among the best in the state, maintaining a remarkable average water quality score of 85/100 across its 41 ZIP codes. Based on recent EPA Safe Drinking Water Act compliance records, water provided by Hnl-windward-pearl Harbor and other municipal suppliers has consistently met or exceeded federal safety standards. This top-tier "A" grade reflects strong infrastructure, diligent monitoring by Hawaii Department of Health, and low contaminant levels.

A major factor in Honolulu's high rating is its flawless health-based violation record. Over the past 5 years of EPA tracking, local water systems have recorded zero health-based violations. This means that regulated contaminants—such as lead, arsenic, and harmful bacteria—have not exceeded the Maximum Contaminant Levels (MCLs) allowed by federal law. Drawing primarily from ground water, the city utilizes advanced filtration to maintain this standard.

Additionally, lead exposure risk remains a critical issue for certain neighborhoods. EPA data indicates that 9 out of 41 ZIP codes in Honolulu are rated as High or Very High risk for lead. This risk is often driven by aging homes with pre-1986 plumbing containing lead solder or service lines. Families in these areas should test their tap water and consider NSF/ANSI 53 certified filters.