June 14, 2026
Flagstaff, AZ Water Quality Report 2026
Unlock the full breakdown — detected levels vs. legal limits, plus what removes each one.
Full contaminant breakdown
EPA Six-Year Review compliance monitoring, 2012–2019 — the most recent national compliance dataset EPA has published. See the sections above for more recent violation and PFAS records.
| Contaminant | Avg. detected | Highest sample | Federal limit | Avg. vs. limit |
|---|---|---|---|---|
| Total trihalomethanes (TTHMs) | 25.9 ppb | 100 ppb | 80 ppb | 32% |
| Haloacetic acids (HAA5) | 18.5 ppb | 96 ppb | 60 ppb | 31% |
| ArsenicEPA health goal: zero | 2.88 ppb | 7.5 ppb | 10 ppb | 29% |
| Chlorite | 161 ppb | 480 ppb | 1000 ppb | 16% |
| Barium | 298 ppb | 1100 ppb | 2000 ppb | 15% |
| Radium (combined)EPA health goal: zero | 0.65 pCi/L | 1.1 pCi/L | 5 pCi/L | 13% |
| Copper | 142 ppb | 380 ppb | 1300 ppb (action level) | 11% |
| LeadEPA health goal: zero | 1.7 ppb | 14 ppb | 15 ppb (action level) | 11% |
| Gross alpha radioactivityEPA health goal: zero | 1.1 pCi/L | 3 pCi/L | 15 pCi/L | 7% |
| UraniumEPA health goal: zero | 1.67 ppb | 2.8 ppb | 30 ppb | 6% |
| Nitrate | 549 ppb | 1900 ppb | 10000 ppb | 5% |
| Nitrate + nitrite | 518 ppb | 1500 ppb | 10000 ppb | 5% |
| Chromium (total) | 1.83 ppb | 2.6 ppb | 100 ppb | 2% |
| Fluoride | 99.8 ppb | 220 ppb | 4000 ppb | 2% |
Also tested, no detections: 1,1,1-Trichloroethane, 1,1,2-Trichloroethane, 1,1-Dichloroethylene, 1,2,4-Trichlorobenzene, 1,2-Dichloroethane, 1,2-Dichloropropane, 2,4,5-TP (Silvex), 2,4-D, Alachlor, Antimony, Asbestos, Atrazine, Benzene, Benzo(a)pyrene, Beryllium, Cadmium, Carbofuran, Carbon tetrachloride, Chlordane, Chlorobenzene, Cyanide, DBCP, DEHA (adipate), DEHP (phthalate), Dalapon, Dichloromethane, Dinoseb, Dioxin (2,3,7,8-TCDD), Diquat, Endothall, Endrin, Ethylbenzene, Ethylene dibromide (EDB), Glyphosate, Heptachlor, Heptachlor epoxide, Hexachlorobenzene, Hexachlorocyclopentadiene, Lindane, Mercury (inorganic), Methoxychlor, Nitrite, Oxamyl, Pentachlorophenol, Picloram, Selenium, Simazine, Styrene, Tetrachloroethylene (PCE), Thallium, Toluene, Toxaphene, Trichloroethylene (TCE), Vinyl chloride, Xylenes (total), cis-1,2-Dichloroethylene, o-Dichlorobenzene, p-Dichlorobenzene, trans-1,2-Dichloroethylene.
Reverse osmosis (drinking water)
The treatment category most often matched to dissolved contaminants like lead, arsenic, nitrate, fluoride, and radiological contaminants detected in this system.
Shop reverse osmosis →Whole-house carbon filtration
The treatment category most often matched to disinfection byproducts (TTHMs, haloacetic acids), chlorine taste and odor, and organic compounds detected in this system.
Shop whole-house systems →Source: U.S. EPA Six-Year Review 4 compliance monitoring data (2012–2019), the most recent nationwide compliance dataset EPA has released, reported at the water-system level. A detection is not a violation. “Avg. vs. limit” compares the average of laboratory detections to the federal MCL or action level; individual faucets can differ — household plumbing affects lead and copper, and a state-certified laboratory test of your own tap is the only way to confirm levels in your home. Treatment categories are general matches, not a certification claim for a specific product and contaminant.
Water Utility: City of Flagstaff
Population Served: 76,960 residents
Data Sources: EPA SDWIS + EPA UCMR5
Report Year: 2026
Flagstaff, Arizona drinking water is supplied by City of Flagstaff. This report summarizes health-based violations and PFAS detections from federal EPA databases.
EPA Health-Based Violation History
The following contaminants exceeded EPA MCLs at this utility since 2010:
| Contaminant | Violation Years | Filter Solution |
|---|---|---|
| Total Haloacetic Acids (HAA5) | 2015 | Whole House Filters |
Source: EPA SDWIS, updated quarterly. Health-based violations only.
PFAS "Forever Chemical" Detections
PFAS compounds were detected during EPA UCMR5 testing (2023-2025).
| PFAS Compound | Level Detected | Solution |
|---|---|---|
| PFBA | 0.0061 ug/L | PFAS Filters |
Source: EPA UCMR5. Levels in ug/L. 1 ug/L = 1,000 ppt.
Should You Filter Your Flagstaff Water?
Flagstaff had a haloacetic acid violation in 2015 and PFAS has been detected recently. Filtration is recommended for all households.
Protect Your Flagstaff Home Water
PureWaterGuys.com carries whole-house and under-sink systems that address haloacetic acids and PFAS. We ship to all Arizona addresses.
Shop Whole House Filters →Take the Water QuizFAQ
Is Flagstaff tap water safe to drink?
City of Flagstaff meets current EPA standards but had a haloacetic acid (HAA5) violation in 2015, and PFBA was detected in UCMR5 testing.
Does Flagstaff water have PFAS?
PFBA was detected during EPA UCMR5 monitoring. A whole-house carbon block or reverse osmosis system is recommended.
What filter works best for Flagstaff?
A whole-house carbon block filter addresses haloacetic acids and chlorine. For PFAS, a reverse osmosis system provides the highest reduction. Take our quiz.
Data sourced from EPA SDWIS and UCMR5. PureWaterGuys.com is not affiliated with any municipal water utility.
Filters for Flagstaff, AZ Water Issues
Based on contaminants detected in this report, these systems are worth considering:
NSF-certified filters proven to remove PFAS, PFOA, PFOS, and 200+ contaminants.
Shop PFAS / Forever Chemicals Filters →
Whole-house carbon filters that eliminate chlorine taste, odor, and DBPs.
Shop Chlorine / Disinfection Byproducts Filters →