Flagstaff tap water is safe to drink. The city’s water system meets all federal drinking water standards, and its most recent Consumer Confidence Report shows no contaminants exceeding EPA maximum levels. Flagstaff draws from a mix of groundwater wells and surface water from Upper and Lower Lake Mary, and the water has consistently tested well within regulatory limits for lead, copper, and other common contaminants.
Lead and Copper Levels
Lead is the contaminant most people worry about in tap water, and Flagstaff has a strong track record here. The city has never exceeded the federal action level for lead or copper in its entire testing history. The 90th percentile lead reading (meaning 90% of samples fall at or below this number) ranges from 2.0 to 3.2 parts per billion, well under the action level of 15 ppb. Copper levels sit between 110 and 290 ppb at the 90th percentile, far below the 1,300 ppb action level.
As of November 2025, the city has identified 70 percent of all water service lines in its system, and none contain lead. Some older properties may have galvanized steel lines that could have absorbed trace lead from pipes that were present decades ago. Under the EPA’s updated Lead and Copper Rule, Flagstaff is required to replace all galvanized service lines by 2037.
PFAS (“Forever Chemicals”)
PFAS contamination has become a major concern nationwide, and Flagstaff’s results are reassuring. During the EPA’s latest round of mandatory PFAS monitoring (known as UCMR5), the city collected samples from multiple sources. Only a single detection was reported: one PFAS compound measured at 6.1 parts per trillion at a Lake Mary entry point during an August sample. The lab reporting threshold was 5 parts per trillion, so this was barely above the detectable range and appeared in just one sample out of the full testing suite.
For additional context, a separate study analyzing wastewater treatment plant effluent in Arizona found that Flagstaff’s samples came back as non-detects for PFAS, meaning levels were below what instruments could even measure. That’s notable because Tucson and Yuma both showed detectable PFAS in their wastewater. Flagstaff’s drinking water supply appears to have minimal PFAS exposure compared to many other communities.
Bacteria and Coliform Testing
The city’s 2024 report noted a Level 1 assessment under the Total Coliform Rule, which is triggered when a routine sample tests positive for coliform bacteria. This doesn’t necessarily mean harmful bacteria entered the water supply. Coliform bacteria are widespread in the environment, and a single positive result often reflects a sampling issue rather than a systemic problem. City staff completed the required assessment with the Arizona Department of Environmental Quality and performed corrective actions, though they did not identify a definitive cause within the distribution system.
Water Treatment and Disinfection
Arizona requires chlorine-based disinfection for all public water supplies. Flagstaff’s surface water from Lake Mary goes through treatment before entering the distribution system, while groundwater from the city’s wells is naturally filtered through volcanic rock formations beneath the San Francisco Peaks. Chlorine disinfection effectively eliminates bacteria, viruses, and other pathogens, though it can sometimes give tap water a slight taste or smell. If you notice a chlorine flavor, filling a pitcher and letting it sit in the refrigerator for an hour or two allows the chlorine to dissipate.
Water Hardness and Taste
Flagstaff’s water comes from volcanic aquifers and mountain reservoirs, which generally produce softer water than what you’d find in the Phoenix metro area or parts of southern Arizona. The region’s geology filters water through basalt and cinder rather than the calcium-rich limestone that creates very hard water. Most Flagstaff residents find the tap water tastes clean without a strong mineral flavor. If you’re moving from a city with noticeably hard water, you’ll likely notice the difference. A water softener is typically unnecessary here.
Older Homes and In-Home Plumbing
Even when the water leaving the treatment plant is clean, your home’s plumbing can introduce contaminants. Homes built before 1986 may have solder joints containing lead, and fixtures manufactured before 2014 could contain higher lead levels than current standards allow. If your home is older, running the cold water tap for 30 seconds to two minutes before drinking (especially first thing in the morning or after the water has sat for several hours) flushes out water that’s been in contact with pipes the longest. Always use cold water for cooking and drinking, since hot water dissolves more metal from pipes and fixtures.
You can request a free copy of the city’s annual water quality report or review it on the Flagstaff city website. If you want to test the water at your specific tap, home testing kits for lead and other contaminants are available through certified labs for around $20 to $50.