What's in the Water in Tucson, AZ?
Monitoring data for Tucson, Arizona shows 21 distinct contaminants detected in the public water supply — Gross Alpha, Uranium, Gross Beta, Total Trihalomethanes, Haloacetic Acids (HAA5), and others. None exceeded the EPA Maximum Contaminant Level in the reported samples.
Contaminants Detected in Tucson
| Contaminant | Detected | EPA Limit (MCL) | Status |
|---|---|---|---|
| Gross Alpha | 7.5 pCi/L | 15 pCi/L | Within limit |
| Uranium | 15 ppb | 30 ppb | Within limit |
| Gross Beta | 25 pCi/L | 50 pCi/L | Within limit |
| Total Trihalomethanes | 40 ppb | 80 ppb | Within limit |
| Haloacetic Acids (HAA5) | 30 ppb | 60 ppb | Within limit |
| Nitrate | 5 ppm | 10 ppm | Within limit |
| Arsenic | 5 ppb | 10 ppb | Within limit |
| Barium | 1000 ppb | 2000 ppb | Within limit |
| Cadmium | 2.5 ppb | 5 ppb | Within limit |
| Chromium | 50 ppb | 100 ppb | Within limit |
| Cyanide | 100 ppb | 200 ppb | Within limit |
| Fluoride | 2000 ppb | 4000 ppb | Within limit |
| Mercury | 1 ppb | 2 ppb | Within limit |
| Antimony | 3 ppb | 6 ppb | Within limit |
| Beryllium | 2 ppb | 4 ppb | Within limit |
| Thallium | 1 ppb | 2 ppb | Within limit |
| Selenium | 25 ppb | 50 ppb | Within limit |
| Trichloroethylene | 2.5 ppb | 5 ppb | Within limit |
| PFOS/PFOA (PFAS) | 2 ppt | 4 ppt | Within limit |
| Atrazine | 1.5 ppb | 3 ppb | Within limit |
| Benzene | 2.5 ppb | 5 ppb | Within limit |
Detected levels are the highest reported across Tucson systems for each contaminant. MCL = EPA Maximum Contaminant Level, the legal safety ceiling. Source: EPA SDWIS monitoring data.
Safety & Violations
| Metric | Value |
|---|---|
| Average Safety Score | 80/100 (B worst) |
| Public Water Systems | 1 |
| Population Served | 732,906 |
| Health Violations | 0 |
| Monitoring Violations | 0 |
| Contaminant Exceedances | 0 |
| Enforcement Actions | 47 |
Frequently Asked Questions
Monitoring data for Tucson, Arizona shows 21 distinct contaminants detected in the public water supply — Gross Alpha, Uranium, Gross Beta, Total Trihalomethanes, Haloacetic Acids (HAA5), and others. None exceeded the EPA Maximum Contaminant Level in the reported samples.
The 1 public water system serving Tucson, Arizona (population 732,906) average a Water Safety Score of 80/100, with a worst grade of B. These systems have no health-based violations on record.
Tucson, Arizona is served by 1 public water system, together supplying water to roughly 732,906 people. The worst safety grade among them is B.
No. In the reported monitoring data for Tucson, no detected contaminant exceeded its EPA Maximum Contaminant Level (MCL).
The Water Safety Score (0-100, graded A-F) weighs health-based violations (40%), contaminant exceedances (30%), enforcement history (20%), and monitoring violations (10%), using EPA Safe Drinking Water Information System (SDWIS) data from the last 10 years.
Request your utility's annual Consumer Confidence Report (CCR), consider an independent test from a state-certified lab, and use an NSF-certified filter targeting any contaminant of concern. For lead specifically, run cold water 30 seconds before drinking.
More about Tucson
Monitoring data for Tucson, Arizona shows 21 distinct contaminants detected in the public water supply — Gross Alpha, Uranium, Gross Beta, Total Trihalomethanes, Haloacetic Acids (HAA5), and others. None exceeded the EPA Maximum Contaminant Level in the reported samples.
This answer pulls from the EPA Safe Drinking Water Information System (SDWIS), the authoritative federal source for U.S. public drinking-water safety. The headline number above is the direct answer; what follows is the additional context most readers need to use the answer for a real decision rather than just a fact lookup.
For readers turning this answer into action: cross-reference against the underlying the EPA Safe Drinking Water Information System (SDWIS) record before acting on time-sensitive decisions. The site renders the data as it was published; subsequent revisions can shift the picture, and the live federal data is always the authoritative current reference.
Source: EPA Ground Water and Drinking Water, 2026.