Arizona vs Nevada
Statewide drinking water quality comparison — violation rates, PFAS prevalence, and system-level risk
Quick Answer
Nevada has a lower open-violation rate (0.0% vs. 0.6%). Arizona has 144 utilities with PFAS records (43.2%) vs. 0 in Nevada (0.0%).
AZ · 333 utilities
0.6%
Open violation rate
43.2%
PFAS detection rate
0
High/critical risk
100.0%
Safe/low risk
NV · 77 utilities
0.0%
Open violation rate
0.0%
PFAS detection rate
0
High/critical risk
100.0%
Safe/low risk
Head-to-Head Comparison
| Metric | Arizona | Nevada |
|---|---|---|
| Total Utilities | 333 | 77 |
| Population Served | 7,200,000 | 3,103,429 |
| Well Water % | 18% on private wells | 10% on private wells |
| Open Violation Rate | 0.6%(2 utilities) | 0.0%(0 utilities) |
| PFAS Detection Rate | 43.2%(144 utilities) | 0.0%(0 utilities) |
| High/Critical Risk Utilities | 0 | 0 |
| Safe/Low Risk Rate | 100.0%(333 utilities) | 100.0%(77 utilities) |
| Top Contaminants |
State Profiles
Arizona
Arizona's water supply depends heavily on the Colorado River (delivered via the Central Arizona Project) and local groundwater. Naturally occurring arsenic is a significant issue in rural areas — Arizona has some of the highest naturally occurring arsenic levels in the U.S. Hard water and PFAS contamination near military installations are also documented. ADEQ holds primary enforcement authority.
Highest-Risk Systems
Nevada
Nevada has 77 community water systems serving approximately 3.1 million residents. Primary water sources include groundwater. The most commonly reported contaminants include disinfection byproducts, lead. 10% of Nevada residents rely on private wells. NDEP holds primary enforcement authority under the Safe Drinking Water Act.
Key Differences
Open violation rate: Arizona at 0.6% vs. Nevada at 0.0%. Nevada has a lower rate of systems with unresolved health-based violations.
PFAS detection: Arizona has PFAS records at 43.2% of utilities vs. 0.0% in Nevada. Rates reflect UCMR 5 monitoring (2023–2025).
Well water reliance: Arizona (18% on private wells) vs. Nevada (10% on private wells). Private well users are not regulated under the Safe Drinking Water Act and should test independently.