Denver, CO Tap Water Quality

Water quality in Denver, CO is currently rated with a moderate C grade (average score: 66/100 across 69 ZIP codes). This rating indicates that while the water provided by Denver Water Board is treated and regulated, there have been notable compliance issues or contaminant detections recently. Residents should stay informed about the specific challenges affecting their local supply.

A major factor in Denver'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 surface 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 25 out of 69 ZIP codes in Denver 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.