Water Quality Report · Updated October 07, 2026
MESA CITY OF
MESA CITY OF delivers tap water graded D (61/100) by TapWaterSafety.org. The utility serves approximately 466,000 residents in MESA, Arizona using surface water. 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. For questions, the utility can be reached at 480-644-3890.
Is MESA tap water safe to drink?
MESA CITY OF delivers tap water that earns a grade of D (61/100) from TapWaterSafety.org — a below-average rating, with multiple concerns including arsenic significantly above health guideline.
The utility serves 466,000 residents in MESA, drawing from surface water.
Public testing data identifies 10 contaminants in this water above EWG's health-based guidelines, including: Arsenic, Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Chromium (hexavalent), Perfluorohexane sulfonate (PFHXS), Haloacetic acids (HAA5), Bromate, Nitrate, Nitrate and nitrite, Chlorite. For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
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.
Quick actions for MESA residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for MESA CITY OF.
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.
Contact MESA CITY OF
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for MESA
Filters matched to the specific contaminants in this 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.
Score breakdown
This utility's overall score of 61/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). 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 (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
MESA CITY OF service area
This water system serves 1 community in Maricopa County, Arizona. Click any city for its dedicated tap water quality page.
Find the right filter for MESA water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.