Water Quality Report · Updated October 07, 2026
TUCSON CITY OF
TUCSON CITY OF delivers tap water graded C (66/100) by TapWaterSafety.org. The utility serves approximately 732,906 residents in TUCSON, Arizona using groundwater. 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 520-837-2430.
Is TUCSON tap water safe to drink?
TUCSON CITY OF delivers tap water that earns a grade of C (66/100) from TapWaterSafety.org — an average rating, with several contaminants above health guidelines but generally compliant with US legal limits.
The utility serves 732,906 residents in TUCSON, drawing from groundwater.
Public testing data identifies 12 contaminants in this water above EWG's health-based guidelines, including: Arsenic, Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Dibromochloromethane, Bromodichloromethane, Chromium (hexavalent), Nitrate, Bromoform, Haloacetic acids (HAA5), Uranium, Chloroform, Radium, combined (-226 and -228). 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 TUCSON CITY OF (system ID AZ0410112) for the last 3 years. Checked 2026-10-07.
| Rule | Type | Since | Status |
|---|---|---|---|
| Radionuclides and Revised Rad Rule | Missed testing or reporting | 01/01/2026 | Open |
| Volatile Organic Chemicals | Missed testing or reporting | 01/01/2026 | Open |
| Synthetic Organic Chemicals | Missed testing or reporting | 01/01/2022 | 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 TUCSON residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for TUCSON CITY OF.
Arsenic significantly above health guideline
Moderate concernArsenic detected at 2.04 ppb, 509x above the EWG health guideline of 0.004 ppb.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 3.93 ppb, 65x above the EWG health guideline of 0.06 ppb.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 9.39 ppb, 63x above the EWG health guideline of 0.15 ppb.
Contact TUCSON 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 TUCSON
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 66/100 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 |
2.04 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 509× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
3.93 ppb | 0.06 | — | — | — | — | — | 65× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
9.39 ppb | 0.15 | 80.0 | 100 | — | — | — | 63× over |
| Dibromochloromethane Disinfection byproduct |
3.52 ppb | 0.1 | — | — | — | — | — | 35× over |
| Bromodichloromethane Disinfection byproduct |
1.94 ppb | 0.06 | — | — | — | — | — | 32× over |
| Chromium (hexavalent) Heavy metal |
0.649 ppb | 0.02 | — | — | — | — | — | 32× over |
| Nitrate Inorganic |
1.68 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 12× over |
| Bromoform Disinfection byproduct |
3.36 ppb | 0.5 | — | — | — | — | — | 6.7× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
0.621 ppb | 0.1 | 60.0 | 60 | — | — | — | 6.2× over |
| Uranium Radiological |
2.23 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 5.2× over |
| Chloroform Disinfection byproduct |
0.583 ppb | 0.4 | — | — | — | — | — | 1.5× over |
| Radium, combined (-226 and -228) Radiological |
0.07 pCi/L | 0.05 | 5.0 | — | — | — | — | 1.4× over |
| Chlorate Disinfection byproduct |
108.8 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Vanadium Other |
6.64 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Barium Heavy metal |
58.4 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Molybdenum Other |
3.08 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Trichloroethylene Volatile organic compound |
0.019 ppb | 0.4 | 5.0 | 10 | 20 | 1.7 | — | Below guideline |
| Atrazine Pesticide/Herbicide |
0.00398 ppb | 0.1 | 3.0 | 0.1 | 100 | 0.15 | — | Below guideline |
| Manganese Heavy metal |
2.6 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| 1,4-Dioxane Semi-volatile organic compound |
0.00458 ppb | 0.35 | — | — | 50 | 1 | — | Below guideline |
| Selenium Heavy metal |
0.307 ppb | 30.0 | 50.0 | 20 | 40 | 30 | — | Below guideline |
| Endothall Pesticide/Herbicide |
0.0633 ppb | 94.0 | 100.0 | — | — | — | — | Below guideline |
| Strontium Radiological |
0.875 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Xylenes (total) Volatile organic compound |
0.468 ppb | 1800.0 | 10000.0 | — | — | — | — | Below guideline |
| Ethylbenzene Volatile organic compound |
0.0545 ppb | 300.0 | 700.0 | 1 | 10 | 0.15 | — | Below guideline |
| Toluene Volatile organic compound |
0.0141 ppb | 150.0 | 1000.0 | — | — | — | — | Below guideline |
| Chlorodifluoromethane Other |
0.00173 ppb | — | — | — | — | — | — | Below guideline |
| Cyanide Inorganic |
0.0549 ppb | — | 200.0 | 50 | 70 | 150 | — | Below guideline |
| Fluoride Inorganic |
0.334 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Germanium Other |
0.192 ppb | — | — | — | — | — | — | Below guideline |
| Lithium Other |
15.7 ppb | — | — | — | — | — | — | Below guideline |
| o-toluidine Other |
0.000175 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.
TUCSON CITY OF service area
This water system serves 1 community in Pima County, Arizona. Click any city for its dedicated tap water quality page.
Find the right filter for TUCSON water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.