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Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
EPA records for FLAGSTAFF CITY OF • Updated September 2026
Grade B — based on EPA compliance records, lead testing and PFAS monitoring
FLAGSTAFF CITY OF is in good standing with EPA, with only minor deductions for monitoring paperwork, low-level PFAS or historical readings near a limit.
Yes — by EPA's records, Flagstaff's tap water earns a B: no health-based violations in five years, lead at 3.6 ppb (90th percentile) and only low-level PFAS (PFBA). Lead from home plumbing is the main remaining risk.
By EPA's records, yes. FLAGSTAFF CITY OF earns a B: no health-based violations in the last five years, a lead 90th-percentile result of 3.6 ppb, and PFAS (PFBA) below federal limits. Lead from your own plumbing is the main risk city data cannot see.
FLAGSTAFF CITY OF's most recent Lead and Copper Rule result (2021-01-01 to 2023-12-31) was 3.6 ppb at the 90th percentile, below EPA's 15 ppb action level. Because lead usually comes from service lines and household plumbing, homes built before 1986 should still test at the tap.
Yes. EPA's UCMR5 sampling (2023-03-28 to 2025-07-15) detected PFBA, all below federal MCLs. Reverse osmosis and certified activated-carbon filters reduce PFAS.
FLAGSTAFF CITY OF has 65 violations on file since 2016: 0 health-based in the last five years and 30 monitoring or reporting violations in that window. Monitoring violations are paperwork lapses, not measured contamination.
FLAGSTAFF CITY OF reports surface water as its primary source and serves about 79,796 people (EPA PWSID AZ0403008).
Optional but sensible. The findings on this page are below federal limits; an NSF-certified pitcher or under-sink filter handles PFAS and improves taste.
Want to know what's really in your Flagstaff tap water?
PFBA were detected in Flagstaff's water at low levels in 2023–2025 EPA monitoring.
Tap Score certified lab · Amazon. We may earn a commission, at no extra cost to you.
FLAGSTAFF CITY OF · SDWIS records since 2016 · 5-year window starts 2021-09-07
EPA records no health-based violations for this system in the last five years. The 30 violations on file in that window are monitoring or reporting paperwork issues, not measured contaminant exceedances.
| Violation | Category | Compliance period | Status |
|---|---|---|---|
| Report Sample Result/Fail Monitor (RTCR)Revised Total Coliform Rule | Reporting | 2025-07-01 | Resolvedreturned 2025-08-12 |
| Monitoring of Treatment (SWTR-Filter)Surface Water Treatment Rule | Monitoring & reporting | 2025-06-01 → 2025-06-30 | Resolvedreturned 2025-06-30 |
| Monitoring, RegularDICHLOROMETHANE | Monitoring & reporting | 2024-01-01 → 2024-12-31 | Resolvedreturned 2024-12-31 |
| Monitoring and Reporting (DBP)Chlorite | Monitoring & reporting | 2023-07-01 → 2023-07-31 | Resolvedreturned 2023-07-31 |
| Monitoring and Reporting (DBP)CARBON, TOTAL | Monitoring & reporting | 2023-04-01 → 2023-06-30 | Resolvedreturned 2023-06-30 |
| Monitoring, Regular1,2,4-Trichlorobenzene | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, Regularcis-1,2-Dichloroethylene | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, Regularo-Dichlorobenzene | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, RegularVinyl chloride | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, Regular1,2-Dichloroethane | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, RegularCarbon tetrachloride | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, Regular1,1,2-Trichloroethane | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, RegularCHLOROBENZENE | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, RegularBenzene | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, RegularStyrene | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, Regulartrans-1,2-Dichloroethylene | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, Regular1,1,1-Trichloroethane | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, Regular1,2-Dichloropropane | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, RegularXylenes, Total | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, Regular1,1-Dichloroethylene | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, RegularEthylbenzene | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, RegularTetrachloroethylene | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, RegularTrichloroethylene | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, RegularToluene | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
| Monitoring, RegularDICHLOROMETHANE | Monitoring & reporting | 2023-01-01 → 2024-06-20 | Resolvedreturned 2024-06-20 |
Showing 25 of 65 violations on file. Full record on EPA ECHO.
Source: ECHO SDWA bulk download (SDWA_VIOLATIONS_ENFORCEMENT.csv, SDWIS 2026Q2, file dated 2026-07-09, fetched 2026-09-06)
EPA Lead and Copper Rule 90th-percentile results reported by FLAGSTAFF CITY OF
Well below the 15 ppb action level. In the most recent monitoring period on file (2021-01-01 to 2023-12-31), 90% of the homes FLAGSTAFF CITY OF sampled had lead at or below 3.6 ppb.
EPA's action level is 15 ppb (dropping to 10 ppb under the 2024 Lead and Copper Rule Improvements). There is no safe level of lead; the 90th-percentile figure describes the system, not your tap — homes with lead service lines or pre-1986 plumbing can be higher.
| Monitoring period | Lead 90th percentile | vs 15 ppb action level |
|---|---|---|
| 2021-01-01 → 2023-12-31 | 3.6 ppb | Well below the 15 ppb action level |
| 2018-01-01 → 2020-12-31 | 2.5 ppb | Well below the 15 ppb action level |
| 2015-01-01 → 2017-12-31 | 2.1 ppb | Well below the 15 ppb action level |
| 2012-01-01 → 2014-12-31 | 2.7 ppb | Well below the 15 ppb action level |
| 2011-01-01 → 2013-12-31 | 2.5 ppb | Well below the 15 ppb action level |
| 2006-01-01 → 2008-12-31 | 1.1 ppb | Well below the 15 ppb action level |
| 2006-01-01 → 2008-12-31 | 1.8 ppb | Well below the 15 ppb action level |
| 2005-01-01 → 2007-12-31 | 1.1 ppb | Well below the 15 ppb action level |
| 2003-01-01 → 2005-12-31 | 2.6 ppb | Well below the 15 ppb action level |
| 2002-01-01 → 2004-12-31 | 2.6 ppb | Well below the 15 ppb action level |
| 2001-01-01 → 2001-12-31 | 2 ppb | Well below the 15 ppb action level |
| 1993-01-01 → 1993-06-30 | 3 ppb | Well below the 15 ppb action level |
Source: ECHO SDWA bulk download (SDWA_LCR_SAMPLES.csv, SDWIS 2026Q2, file dated 2026-07-09, fetched 2026-09-06)
EPA UCMR5 monitoring, 2023-03-28 to 2025-07-15 · 696 PFAS results at entry points to the distribution system
PFBA detected at low levels; no compound was at or above its federal MCL. Detections below the MCL are common in surface-water systems and are reported here exactly as EPA published them.
| Compound | Detects / samples | Max (ppt) | Reporting limit | EPA MCL |
|---|---|---|---|---|
| PFOA | 0 / 24 | < 4 | 4 ppt | 4 ppt |
| PFOS | 0 / 24 | < 4 | 4 ppt | 4 ppt |
| PFHxS | 0 / 24 | < 3 | 3 ppt | 10 ppt |
| PFNA | 0 / 24 | < 4 | 4 ppt | 10 ppt |
| HFPO-DA | 0 / 24 | < 5 | 5 ppt | 10 ppt |
| PFBS | 0 / 24 | < 3 | 3 ppt | hazard index only |
| PFBA | 1 / 24 | 6.1 | 5 ppt | hazard index only |
“< 4 ppt” means below the laboratory reporting limit, not zero. ppt = parts per trillion (ng/L). Results are for finished water leaving the treatment plant.
What PFAS are and how to remove them → · Best filters for PFAS →
Source: UCMR5 occurrence data, EPA Data Summary July 2026 (UCMR5_All.txt)
EPA Six-Year Review 4 compliance samples for FLAGSTAFF CITY OF · finished water only · dated data, released 2024
These are the regulated-contaminant samples FLAGSTAFF CITY OF reported to its state between 2012 and 2019 — the most recent nationwide sample-level dataset EPA has published. Total trihalomethanes (TTHM), Haloacetic acids (HAA5) are flagged below; the status column explains why. Treat this as history, not today's tap water.
| Contaminant | Samples | Average | Max | EPA limit | Status |
|---|---|---|---|---|---|
| Arsenic | 1918 detects | 2.732 µg/L | 7.5 µg/L | 10 µg/LMCL | Within MCL |
| Nitrate (as N) | 7971 detects | 0.493 mg/L | 1.9 mg/L | 10 mg/LMCL | Within MCL |
| Fluoride | 19 | 0.1 mg/L | 0.22 mg/L | 4 mg/LMCL | Within MCL |
| Chromium (total) | 1910 detects | 0.963 µg/L | 2.6 µg/L | 100 µg/LMCL | Within MCL |
| Uranium (combined) | 119 detects | 1.366 µg/L | 2.8 µg/L | 30 µg/LMCL | Within MCL |
| Radium-226/228 | 114 detects | 0.236 pCi/L | 1.1 pCi/L | 5 pCi/LMCL | Within MCL |
| Gross alpha | 117 detects | 0.7 pCi/L | 3 pCi/L | 15 pCi/LMCL | Within MCL |
| Total trihalomethanes (TTHM) | 269252 detects | 24.22 µg/L | 100 µg/L | 80 µg/LMCL (LRAA) | 5 single samples over MCL; average within limit |
| Haloacetic acids (HAA5) | 269225 detects | 15.508 µg/L | 96 µg/L | 60 µg/LMCL (LRAA) | 9 single samples over MCL; average within limit |
| Lead (tap samples) | 6247 detects | 1.287 µg/L | 14 µg/L | 15 µg/Laction level (90th percentile) | Reported, not scored (compliance is on the 90th percentile) |
| Copper (tap samples) | 62 | 142.129 µg/L | 380 µg/L | 1300 µg/Laction level (90th percentile) | Reported, not scored (compliance is on the 90th percentile) |
Averages count non-detects as zero. TTHM and HAA5 limits are locational running annual averages, so a single high sample is not a violation — we grade those on the average only. Lead and copper rows are individual tap samples and are shown for context; compliance (and our score) uses the 90th-percentile result above. LRAA = locational running annual average; ND = not detected.
Source: SYR4 Six-Year Review compliance monitoring data 2012–2019 (released 2024-03)
FLAGSTAFF CITY OF · 21,947 service lines inventoried · Q2 2026 snapshot
FLAGSTAFF CITY OF reports 1,326 service lines that are lead or galvanized-requiring-replacement (6.0% of the lines it has inventoried), plus 5,078 lines whose material is still unknown. A lead service line is the pipe between the water main and a building, so treated water can pick up lead after it leaves the plant — which city-level testing does not capture. Under EPA's Lead and Copper Rule Improvements, utilities must replace lead lines within 10 years starting in 2027.
Source: EPA SDWIS Service Line Inventory (Q2 2026) · PWS ID AZ0403008 · See all Arizona lead service lines. We may earn a commission from filters and test kits, at no extra cost to you.
Surface-water systems draw from rivers, lakes or reservoirs and must filter and disinfect, which is why disinfection byproducts (TTHM, HAA5) are the readings to watch.
How to test your tap water and the treatment options that actually fit Flagstaff homes
The most reliable way to know what is actually coming out of your tap is a certified mail-in lab test. City-wide EPA data (like the report above) reflects the water leaving the treatment plant, but contaminants such as lead and copper can be picked up from your own service line and household plumbing — so the water at your Flagstaff faucet can differ from the system average. A state-certified lab measures dozens of contaminants at once with results you can trust; you can also find one near you through the EPA's certified-lab list at epa.gov/dwlabcert. Hardware-store test strips are cheaper and instant, but they only screen for a few basics (chlorine, hardness, pH, and a rough lead pass/fail) and are far less accurate — treat them as a first look, not a diagnosis.
Match the treatment to what your test finds. Reverse osmosis (RO) removes the widest range of contaminants — lead, arsenic, nitrate, PFAS, and dissolved solids — which makes an under-sink reverse osmosis system the most thorough choice for Flagstaff households with heavy-metal or PFAS concerns. If your main issue is taste, odor, or chlorine, an activated carbon filter (pitcher, faucet, or under-sink) is simpler and cheaper and handles chlorine and many organic compounds well, though carbon alone does not remove arsenic, nitrate, or most PFAS. NSF-certified pitchers rated for lead reduction are the easiest way to start today while you decide on a permanent setup.
We may earn a commission from testing kits and filters purchased through these links, at no extra cost to you.
Flagstaff ranks #16 of 37 graded Arizona cities.
By EPA's records, yes. FLAGSTAFF CITY OF earns a B: no health-based violations in the last five years, a lead 90th-percentile result of 3.6 ppb, and PFAS (PFBA) below federal limits. Lead from your own plumbing is the main risk city data cannot see.
FLAGSTAFF CITY OF's most recent Lead and Copper Rule result (2021-01-01 to 2023-12-31) was 3.6 ppb at the 90th percentile, below EPA's 15 ppb action level. Because lead usually comes from service lines and household plumbing, homes built before 1986 should still test at the tap.
Yes. EPA's UCMR5 sampling (2023-03-28 to 2025-07-15) detected PFBA, all below federal MCLs. Reverse osmosis and certified activated-carbon filters reduce PFAS.
FLAGSTAFF CITY OF has 65 violations on file since 2016: 0 health-based in the last five years and 30 monitoring or reporting violations in that window. Monitoring violations are paperwork lapses, not measured contamination.
FLAGSTAFF CITY OF reports surface water as its primary source and serves about 79,796 people (EPA PWSID AZ0403008).
Optional but sensible. The findings on this page are below federal limits; an NSF-certified pitcher or under-sink filter handles PFAS and improves taste.
PFBA were detected in Flagstaff's water at low levels in 2023–2025 EPA monitoring.
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Based on contaminants detected in your water, these resources may be helpful:
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