City of Flagstaff
EPA ID: AZ0403008 · 76,960 people served · 6 ZIP codes
Per EPA records, City of Flagstaff: 6 unresolved violations, 76,960 people in service area.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Worsening · Risk tier: High · 95% chance of violation in next 12 months
Violations went from 6 (2023) to 12 (2024). The pattern suggests growing compliance challenges.
Service Area Map
Coverage area for City of Flagstaff Source: EPA SDWIS service area boundaries.
Service area boundary — Grade C
Service Area Demographics
The City of Flagstaff serves a community with a median household income of $77,486 and an estimated 95,135 residents across its service area.
Environmental Justice Note: 39% of the population in this service area is classified as disadvantaged under EPA's EJScreen criteria. Communities with higher disadvantaged populations often face disproportionate environmental and health burdens, including aging water infrastructure and limited resources for remediation.
🌊 Where Does Your Water Come From?
City of Flagstaff's water is drawn from rivers, lakes, or reservoirs. Surface water sources are more exposed to agricultural runoff, stormwater, and upstream discharges, but they typically receive more intensive treatment before reaching your tap.
About 6% of homes in Coconino County, Arizona rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Wastewater Proximity Note: This service area ranks in the 60th percentile nationally for proximity to wastewater discharge points. Surface water sources near wastewater outfalls may face additional treatment challenges.
Infrastructure Risk
Detected Contaminants
How City of Flagstaff compares to EPA limits
What This Means For You
Contaminant 1009 at 1 mg/L exceeds the EPA maximum of 0.004 mg/L. Intestinal damage, bone damage. Consider reverse osmosis filtration.
Dichloroacetic Acid at 1 mg/L exceeds the EPA maximum of 0.06 mg/L.
Total Trihalomethanes (TTHM) at 1 mg/L exceeds the EPA maximum of 0.08 mg/L. Bladder & rectal cancer risk; reproductive concerns. Consider granular activated carbon (GAC) filtration.
Chlorite at 3 mg/L exceeds the EPA maximum of 1 mg/L. Anemia and nervous system effects in infants and children. Consider ferrous sulfate reduction filtration.
Consumer Confidence Report Rule at 3 mg/L exceeds the EPA maximum of mg/L.
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 4 detections recorded.
Contaminant 1009 was detected in this water system. reverse osmosis filtration can reduce exposure.
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Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
City of Flagstaff (EPA ID: AZ0403008) is a community water system in Arizona that serves approximately 76,960 people from surface water sources.
This system provides water to 6 ZIP codes across 1 community.
Average Home Safety Score: C (65/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| July 1, 2025 | Consumer Confidence Report Rule | Monitoring | Resolved |
| June 1, 2025 | E. coli | Monitoring | Resolved |
| March 1, 2025 | Revised Total Coliform Rule | Monitoring | Unresolved |
| June 1, 2024 | Consumer Confidence Report Rule | Monitoring | Resolved |
| January 1, 2024 | Dichloroacetic Acid | Monitoring | Resolved |
| July 1, 2023 | Contaminant 1009 | Monitoring | Unresolved |
| April 1, 2023 | Chlorite | Monitoring | Unresolved |
| February 1, 2023 | Consumer Confidence Report Rule | Monitoring | Resolved |
| January 1, 2023 | Total Organic Carbon | Monitoring | Resolved |
| January 1, 2023 | Stage 1 DBP Rule | Monitoring | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Chlorite | Disinfection Byproducts | 3 | No |
| Consumer Confidence Report Rule | Reporting Failure | 3 | No |
| Stage 1 DBP Rule | Treatment Failure | 2 | No |
| E. coli | Microbiological | 2 | No |
| Contaminant 1009 | Other Violation | 1 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 1 | No |
| Contaminant 2959 | Other Violation | 1 | No |
| Dichloroacetic Acid | Disinfection Byproducts | 1 | No |
| Total Organic Carbon | Disinfection Byproducts | 1 | No |
| Total Coliform | Microbiological | 1 | No |
| Radium-228 | Radionuclides | 1 | No |
| Surface Water Treatment Rule | Treatment Failure | 1 | No |
| Fecal Coliform | Microbiological | 1 | No |
| Revised Total Coliform Rule | Microbiological | 1 | No |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 86001 | 0.0029 mg/L | No | N/A |
| 86002 | 0.0029 mg/L | No | N/A |
| 86003 | 0.0029 mg/L | No | N/A |
| 86004 | 0.0029 mg/L | No | N/A |
| 86005 | 0.0029 mg/L | No | N/A |
| 86011 | 0.0029 mg/L | No | N/A |
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 2 (Moderate Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Coverage: 4 ZIP codes confirmed via EPA Community Water System Service Area Boundaries v3 plus 2 additional ZIPs inferred from SDWIS registry data. The EPA-confirmed set is the most reliable; SDWIS-inferred entries may be narrower than the real deployment area.
- 86001 — Flagstaff
- 86002 — Flagstaff
- 86003 — Flagstaff
- 86004 — Flagstaff
- 86005 — Flagstaff
- 86011 — Flagstaff
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for City of Flagstaff (AZ0403008) on EPA.gov.
Frequently Asked Questions
Is City of Flagstaff water safe to drink?
City of Flagstaff has only monitoring/reporting violations, which are procedural in nature. The system meets federal health-based standards.
How many people does City of Flagstaff serve?
City of Flagstaff serves approximately 76,960 people across 6 ZIP codes in Arizona.
Where does City of Flagstaff get its water?
The primary water source is surface water.
Contact Your Water Utility
Public-record contact information for the water utility serving this system. Use these channels to request water quality reports, ask about service, or report issues directly.
Contact information from City of Flagstaff Water Services Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility, does not act as its agent, and does not provide customer support for it. Contact details shown are public-record information from CCR filings. For service issues, contact the utility directly using the information above.
Water Source & Treatment
Where this water originates and how it's treated before reaching your tap.
Source: City of Flagstaff Water Services Consumer Confidence Report.
ZipCheckup is not affiliated with this water utility. Treatment and source data are sourced from the utility's published CCR filings.
Based on the information currently available on the hydrogeologic settings and the adjacent land uses that are in the specified proximity of the drinking water sources of this public water system, the Arizona Department of Environmental Quality (ADEQ) has given a low-risk designation for the degree to which this public water system's drinking water sources are protected. A low-risk designation indicates that most source water protection measures are either already implemented or the hydrogeology is such that additional source water protection measures will have little impact on protection.
Treatment regime
How this utility classifies its treatment process and what each reported treatment chemical does.
Treatment chemicals and what each one does
Chemical names are reported verbatim by the utility. Purpose categories are ZipCheckup annotations based on standard drinking-water treatment practice.
Treatment classification and chemical list sourced from City of Flagstaff Water Services Consumer Confidence Report.
Treatment intensity is a ZipCheckup-derived classification based on the chemicals and processes the utility reports. Chemicals and contamination sources are taken verbatim from the utility's CCR filing. Routine federal monitoring and contaminant testing shown elsewhere on this page determine whether the water meets safety standards, not the treatment classification.
Federal UCMR5 PFAS Monitoring: Detected
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). PFAS compounds were detected below the current state-enforceable MCL.
Current MCL reflects the lowest state-enforceable limit (NYS 10 ppt for PFOA/PFOS, effective August 2020). The federal final MCL of 4 ppt for PFOA/PFOS (EPA April 2024 rule) is not enforceable until April 2029. Detections above 4 ppt but below 10 ppt are below current MCL but above the future federal limit.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.
How Water Systems Appear in Rankings
Water systems are evaluated by violation history, contaminant detections, and service population. Larger systems with more service connections appear in more rankings.
Frequently Asked Questions
What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
City of Flagstaff (EPA ID: AZ0403008) — request the latest Consumer Confidence Report or ask about specific contaminants.