Tap Water Quality Report
Tap water quality in Mesa, Arizona
Tap water in Mesa, Arizona receives a grade of D (61/100) from TapWaterSafety.org. It's served by MESA CITY OF. The most significant water quality concerns are: Arsenic significantly above health guideline; Haloacetic acids (HAA9) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.
What's in Mesa's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving Mesa.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 4.35 ppb, 1087x above the EWG health guideline of 0.004 ppb.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 31.8 ppb, 530x above the EWG health guideline of 0.06 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 42.8 ppb, 285x above the EWG health guideline of 0.15 ppb.
EPA compliance record
Official U.S. EPA records for MESA CITY OF (system ID AZ0407095) for the last 3 years. Checked 2026-10-07.
| Rule | Type | Since | Status |
|---|---|---|---|
| Revised Total Coliform Rule | Missed testing | 08/01/2025 | Open |
| Stage 1 Disinfectants and Disinfection Byproducts Rule | Missed testing or reporting | 02/01/2025 | Open |
| Volatile Organic Chemicals | Missed testing or reporting | 01/01/2023 | Open |
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Recommended filters for Mesa
Filters matched to the specific contaminants in Mesa's water supply.
Reverse osmosis certified for arsenic (NSF/ANSI 58)
$429-$599Reverse osmosis certified under NSF/ANSI 58 for arsenic is the most reliable home option.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in Mesa's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Arsenic Heavy metal |
4.35 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 1087× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
31.8 ppb | 0.06 | — | — | — | — | — | 530× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
42.8 ppb | 0.15 | 80.0 | 100 | — | — | — | 285× over |
| Chromium (hexavalent) Heavy metal |
5.63 ppb | 0.02 | — | — | — | — | — | 281× over |
| Perfluorohexane sulfonate (PFHXS) PFAS |
0.231 ppt | 0.001 | 10.0 | — | — | — | — | 231× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
10.9 ppb | 0.1 | 60.0 | 60 | — | — | — | 109× over |
| Bromate Disinfection byproduct |
4.84 ppb | 0.1 | 10.0 | 10 | 10 | 0.1 | — | 48× over |
| Nitrate Inorganic |
3.04 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 22× over |
| Nitrate and nitrite Inorganic |
2.39 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 17× over |
| Chlorite Disinfection byproduct |
209.0 ppb | 50.0 | 1000.0 | — | — | — | — | 4.2× over |
| 1,2-Dibromo-3-chloropropane (DBCP) Other |
0.00124 ppb | 0.0017 | 0.2 | — | — | — | — | Below guideline |
| Radium, combined (-226 and -228) Radiological |
0.03 pCi/L | 0.05 | 5.0 | — | — | — | — | Below guideline |
| Chlorate Disinfection byproduct |
94.8 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
7.5 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Tetrachloroethylene (perchloroethylene) Volatile organic compound |
0.02 ppb | 0.06 | 5.0 | — | — | — | — | Below guideline |
| Barium Heavy metal |
36.6 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Bromochloromethane Other |
0.00274 ppb | 0.06 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
1.62 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Selenium Heavy metal |
1.21 ppb | 30.0 | 50.0 | 20 | 40 | 30 | — | Below guideline |
| 1,4-Dioxane Semi-volatile organic compound |
0.00885 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Di(2-ethylhexyl) phthalate Semi-volatile organic compound |
0.0622 ppb | 3.0 | 6.0 | — | — | — | — | Below guideline |
| Trichloroethylene Volatile organic compound |
0.00643 ppb | 0.4 | 5.0 | 10 | 20 | 1.7 | — | Below guideline |
| Manganese Heavy metal |
1.31 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Dichloromethane (methylene chloride) Volatile organic compound |
0.00595 ppb | 4.0 | 5.0 | — | — | — | — | Below guideline |
| Strontium Radiological |
0.599 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Cobalt Other |
0.00859 ppb | 70.0 | — | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
0.089 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.131 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Chlorodifluoromethane Other |
0.00492 ppb | — | — | — | — | — | — | Below guideline |
| Chromium (total) Heavy metal |
6.84 ppb | — | 100.0 | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.315 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Germanium Other |
0.274 ppb | — | — | — | — | — | — | Below guideline |
| Lithium Other |
164.8 ppb | — | — | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from MESA CITY OF.