Flagstaff, AZ: 120 Violations — 65/100 (2026)
6 ZIP codes · 5 water systems · Updated 2026-06-03
Safe water is the norm across most of Flagstaff, AZ — but documented violations push the city to the middle safety tier.
How Flagstaff Compares
Data: EPA SDWIS Last verified: 2026-06-03
Water Quality Map: Flagstaff, AZ
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Score Distribution
How ZIP codes in Flagstaff score across all safety grades.
What You Should Know About Flagstaff Water
- Your city's water systems recorded 120 violations in the past 5 years.
- Average lead level: 0.0029 mg/L.
- Homes built before 1986: 37% — older plumbing may contain lead solder.
- Estimated remediation: $1,333 per household.
- CDC health risk index: 10.52.
Who Supplies Your Water in Flagstaff
Flagstaff, AZ is covered by 3 major water utilities out of 5 federally tracked systems, each managing its own pipes, treatment processes, and EPA filings. What a household gets from the tap depends on which provider's system serves that address.
Overview
We track water quality and home safety data for 6 ZIP codes in Flagstaff, Arizona, covering 5 community water systems serving approximately 95,135 people.
6 of 6 ZIP codes (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Flagstaff: C (65/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Flagstaff water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0029 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 2 (Moderate Risk)
- Zone 1 (High): 0 ZIP codes
- Zone 2 (Moderate): 6 ZIP codes
- Zone 3 (Low): 0 ZIP codes
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Chlorite | Disinfection Byproducts | 21 | 6 |
| Consumer Confidence Report Rule | Reporting | 21 | 6 |
| Stage 1 DBP Rule | Treatment Technique | 14 | 6 |
| E. coli | Microbiological | 14 | 6 |
| Contaminant 1009 | Other | 7 | 6 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 86001 | C | 20 | 0 | City of Flagstaff |
| 86002 | C | 20 | 0 | City of Flagstaff |
| 86003 | C | 20 | 0 | City of Flagstaff |
| 86004 | C | 20 | 0 | City of Flagstaff |
| 86005 | C | 20 | 0 | City of Flagstaff |
| 86011 | C | 20 | 0 | City of Flagstaff |
All ZIP Codes in Flagstaff
- 86001 [C] — 20 violations
- 86002 [C] — 20 violations
- 86003 [C] — 20 violations
- 86004 [C] — 20 violations
- 86005 [C] — 20 violations
- 86011 [C] — 20 violations
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
Health Outcomes in Flagstaff
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Top Contaminants in Flagstaff Water
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Housing & Infrastructure in Flagstaff
Housing age data helps assess potential lead pipe and infrastructure risks. Newer housing stock generally means lower plumbing-related contamination risk.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Plumbing risk in residential housing tracks directly to construction era: pre-1986 homes may have lead-soldered copper joints; pre-1970 homes may have lead pipes outright. Flagstaff's median build year of 1995 places the city in a moderate risk zone where neither era dominates the housing inventory. Understanding which side of the 1986 threshold a specific property falls on — and whether it predates 1970 — is the most actionable starting point for a homeowner trying to assess their own tap water exposure.
Most homes in Flagstaff were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.
Source: U.S. Census Bureau ACS B25034.
Cost Context: What Remediation Means for Flagstaff Homeowners
At current valuations, Flagstaff sits in the low remediation-share tier — the equity impact of fixing documented issues is proportionally minor.
Remediation costs in Flagstaff are relatively low compared to home values. The $600–$2,233 estimated range is a small fraction of median property value. Home values are 82% above the Arizona average.
Lead Exposure Risk for Children in Flagstaff
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
After the federal action removing lead-bearing solder from new plumbing took effect, building practice shifted — but 37% of the Flagstaff inventory predates that line. With aggregate samples near or beyond 0.015 mg/L, an in-home check moves out of the optional column into the standard list.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Flagstaff
Flood risk in Flagstaff occupies the middle ground: 143 NFIP claims and 50% of local ZIP codes within FEMA flood zones. At that level, the risk pathways connecting flooding to water quality — treatment system stress, well infiltration, distribution backflow — become relevant considerations during significant flood events, even if day-to-day water quality is unaffected by flood history.
Flagstaff has a moderate flood history with 143 FEMA claims averaging $13,061 per payout. 50% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$1,333</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
What You Can Do in Flagstaff
- Test your water at home. City-level data shows averages — your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
- Install a certified water filter. Filters rated for Chlorite can reduce the most common contaminant found in Flagstaff's water.
- Check your home's plumbing. With 37% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Flagstaff, AZ