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Community Water System · PWS AZ0407095

Mesa City Of

Mesa, Arizona 85211 - drinking water served from surface water sources to 466,000 people, tracked in EPA SDWIS and UCMR5.

466,000
People served
1,739
EPA violations
3
Health-based
3 PFAS
UCMR5 result

The verdict

EPA records 1,739 drinking-water violations at Mesa City Of - above the Arizona per-system average, and UCMR5 testing detected 3 PFAS compounds.

1,739
Total EPA violations on record
0%
Health-based (MCL / treatment failure)
466,000
People served by this system
3
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Mesa City Of

Mesa City Of is a local-owned community water system that delivers drinking water to 466,000 residents in Mesa, Arizona (Maricopa County) through 142,500 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 1,739 total violations for this system , of which 3 (0%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 1,713 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.

The most frequently cited contaminant at this system is Nitrate, recorded in 126 violations (MR). Under EPA's UCMR5 PFAS monitoring program, 3 PFAS compounds were detected in samples collected from this system, with a maximum reported concentration of 15.2 ppt (parts per trillion). PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

Across Arizona, EPA tracks 1,493 public water systems serving 7,322,166 people, with 228,944 cumulative violations and 15,663 health-based violations on record. About 98% of systems in the state carry at least one violation, and state-wide the average per system is 153.3 violations. Statewide, 145 of 152 UCMR5-tested systems have reported PFAS detections (95.4%).

Mesa City Of's 1,739 violations sit above the Arizona average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

PFAS Detected

3 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
466,000
Total Violations
1,739
Health-Based Violations
3
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
142,500
County
Maricopa
School/Daycare
No
MCL Violations
3
Monitoring Violations
1,713
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Nitrate MR 126 2020
Glyphosate MR 70 2009
2,3,7,8-TCDD MR 68 2009
Tetrachloroethylene MR 67 2023
HEXACHLOROBENZENE MR 43 2006
Benzo(a)pyrene MR 43 2006
Di(2-ethylhexyl) adipate MR 42 2006
Simazine MR 42 2006
Hexachlorocyclopentadiene MR 41 2006
Atrazine MR 41 2006
Di(2-ethylhexyl) phthalate MR 41 2023
Endrin MR 38 2006
BHC-GAMMA MR 38 2006
Heptachlor MR 36 2006
Heptachlor epoxide MR 36 2006
OXAMYL MR 36 2006
LASSO MR 35 2006
Carbofuran MR 35 2006
Toxaphene MR 29 2006
2,4-D MR 28 2006
2,4,5-TP MR 28 2006
Methoxychlor MR 28 2006
Dalapon MR 25 2006
Picloram MR 25 2006
Pentachlorophenol MR 24 2006
Diquat MR 23 2006
Endothall MR 23 2006
DICHLOROMETHANE MR 23 2023
Dinoseb MR 23 2006
ETHYLENE DIBROMIDE MR 20 2006

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 15 of 2030 samples detected PFAS.

Contaminant Date Result MRL Status
NEtFOSAA 9/6/2023 <5.00 ppt 5.00 ppt Not Detected
PFHxS 9/6/2023 <3.00 ppt 3.00 ppt Not Detected
PFTA 9/6/2023 <8.00 ppt 8.00 ppt Not Detected
HFPO-DA 9/6/2023 <5.00 ppt 5.00 ppt Not Detected
PFBS 9/6/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpA 9/6/2023 <3.00 ppt 3.00 ppt Not Detected
PFMPA 9/6/2023 <4.00 ppt 4.00 ppt Not Detected
PFPeA 9/6/2023 <3.00 ppt 3.00 ppt Not Detected
PFMBA 9/6/2023 <3.00 ppt 3.00 ppt Not Detected
PFEESA 9/6/2023 <3.00 ppt 3.00 ppt Not Detected
NFDHA 9/6/2023 <20.00 ppt 20.00 ppt Not Detected
PFPeS 9/6/2023 <4.00 ppt 4.00 ppt Not Detected
PFHpS 9/6/2023 <3.00 ppt 3.00 ppt Not Detected
PFDoA 9/6/2023 <3.00 ppt 3.00 ppt Not Detected
PFNA 9/6/2023 <4.00 ppt 4.00 ppt Not Detected
PFOS 9/6/2023 <4.00 ppt 4.00 ppt Not Detected
NMeFOSAA 9/6/2023 <6.00 ppt 6.00 ppt Not Detected
PFOA 9/6/2023 <4.00 ppt 4.00 ppt Not Detected
PFTrDA 9/6/2023 <7.00 ppt 7.00 ppt Not Detected
8:2 FTS 9/6/2023 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 9/6/2023 <3.00 ppt 3.00 ppt Not Detected
6:2 FTS 9/6/2023 <5.00 ppt 5.00 ppt Not Detected
ADONA 9/6/2023 <3.00 ppt 3.00 ppt Not Detected
9Cl-PF3ONS 9/6/2023 <2.00 ppt 2.00 ppt Not Detected
11Cl-PF3OUdS 9/6/2023 <5.00 ppt 5.00 ppt Not Detected
PFUnA 9/6/2023 <2.00 ppt 2.00 ppt Not Detected
PFHxA 9/6/2023 <3.00 ppt 3.00 ppt Not Detected
PFBA 9/6/2023 <5.00 ppt 5.00 ppt Not Detected
PFDA 9/6/2023 <3.00 ppt 3.00 ppt Not Detected
11Cl-PF3OUdS 9/5/2023 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 9/5/2023 <3.00 ppt 3.00 ppt Not Detected
PFDA 9/5/2023 <3.00 ppt 3.00 ppt Not Detected
PFDoA 9/5/2023 <3.00 ppt 3.00 ppt Not Detected
NFDHA 9/5/2023 <20.00 ppt 20.00 ppt Not Detected
NEtFOSAA 9/5/2023 <5.00 ppt 5.00 ppt Not Detected
PFHxA 9/5/2023 <3.00 ppt 3.00 ppt Not Detected
PFOS 9/5/2023 <4.00 ppt 4.00 ppt Not Detected
PFUnA 9/5/2023 <2.00 ppt 2.00 ppt Not Detected
PFNA 9/5/2023 <4.00 ppt 4.00 ppt Not Detected
9Cl-PF3ONS 9/5/2023 <2.00 ppt 2.00 ppt Not Detected
ADONA 9/5/2023 <3.00 ppt 3.00 ppt Not Detected
HFPO-DA 9/5/2023 <5.00 ppt 5.00 ppt Not Detected
PFPeS 9/5/2023 <4.00 ppt 4.00 ppt Not Detected
PFBA 9/5/2023 <5.00 ppt 5.00 ppt Not Detected
6:2 FTS 9/5/2023 <5.00 ppt 5.00 ppt Not Detected
PFTA 9/5/2023 <8.00 ppt 8.00 ppt Not Detected
8:2 FTS 9/5/2023 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 9/5/2023 <7.00 ppt 7.00 ppt Not Detected
NMeFOSAA 9/5/2023 <6.00 ppt 6.00 ppt Not Detected
PFEESA 9/5/2023 <3.00 ppt 3.00 ppt Not Detected

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Mesa City Of.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID AZ0407095 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Arizona Drinking Water Authority

Arizona DEQ, Drinking Water Program is the primacy agency that licenses and inspects Mesa City Of under EPA-delegated authority.

Open AZ regulator portal

Source: Arizona DEQ, Drinking Water Program

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2025 Bromate MR 6 SDWIS / AZ0407095 / 1011
2025 Revised Total Coliform Rule MON 1 SDWIS / AZ0407095 / 8000
2023 Tetrachloroethylene MR 67 SDWIS / AZ0407095 / 2987
2023 Di(2-ethylhexyl) phthalate MR 41 SDWIS / AZ0407095 / 2039
2023 DICHLOROMETHANE MR 23 SDWIS / AZ0407095 / 2964
2023 1,2,4-Trichlorobenzene MR 20 SDWIS / AZ0407095 / 2378
2023 cis-1,2-Dichloroethylene MR 20 SDWIS / AZ0407095 / 2380
2023 o-Dichlorobenzene MR 20 SDWIS / AZ0407095 / 2968
2023 1,1-Dichloroethylene MR 20 SDWIS / AZ0407095 / 2977
2023 Carbon tetrachloride MR 20 SDWIS / AZ0407095 / 2982
2023 Benzene MR 20 SDWIS / AZ0407095 / 2990
2023 Toluene MR 20 SDWIS / AZ0407095 / 2991
2023 Styrene MR 20 SDWIS / AZ0407095 / 2996
2023 p-Dichlorobenzene MR 20 SDWIS / AZ0407095 / 2969
2023 1,2-Dichloropropane MR 20 SDWIS / AZ0407095 / 2983

How Mesa City Of Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Mesa City Of Arizona avg Federal benchmark
Total violations 1,739 153.3 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 3 10.5 Indicates a contaminant exceeded a federal MCL
PFAS detection 3 compounds 95.4% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 466,000 4,904 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 1,493 regulated public water systems in Arizona.

Federal MCL reference, Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Mesa City Of water safe to drink? ▼
Mesa City Of (PWS ID: AZ0407095) has 1739 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 3 PFAS compounds found. This system serves 466,000 people using Surface Water sources.
How many people does Mesa City Of serve? ▼
Mesa City Of serves 466,000 people in Mesa, Arizona. It is a Local-owned system using Surface Water water sources with 142,500 service connections.
What type of violations does Mesa City Of have? ▼
Mesa City Of has 1,739 total violations: 3 health-based violations (MCL exceedances or treatment failures), 1,713 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Mesa City Of water? ▼
Yes. UCMR5 testing detected 3 PFAS compounds in Mesa City Of's water supply: PFBS, PFHxS, PFHxA. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does Mesa City Of use? ▼
Mesa City Of uses Surface Water as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.