Nevada Water Quality Report: 691 Violations Across 254 ZIPs
165 water systems · 254 ZIP codes · 691 violations · Updated 2026-05-31
Data: EPA Safe Drinking Water Information System (SDWIS), EPA ECHO Last verified: 2026-05-31
City Water Quality Map: Nevada
Each circle represents a city. Size indicates population, color indicates water quality grade. Tap a circle for details.
Violation Trend
EPA violations across all water systems in Nevada.
Cities with Most Violations in Nevada
| # | City | Grade | Violations | Systems | Population | |
|---|---|---|---|---|---|---|
| 1 | Las Vegas | A | 308 | 5 | 1,563,833 | Details → |
| 2 | Reno | B | 48 | 5 | 454,618 | Details → |
| 3 | Elko | B | 24 | 5 | 23,659 | Details → |
| 4 | Gerlach | C | 24 | 2 | 530 | Details → |
| 5 | Boulder City | A | 22 | 4 | 16,214 | Details → |
| 6 | Empire | B | 22 | 1 | 350 | Details → |
| 7 | Battle Mountain | C | 19 | 2 | 3,985 | Details → |
| 8 | Sparks | B | 18 | 2 | 1,345 | Details → |
| 9 | Austin | C | 17 | 2 | 700 | Details → |
| 10 | Goldfield | B | 14 | 2 | 488 | Details → |
Cities with Best Water Quality in Nevada
| # | City | Grade | Score | Systems | Population |
|---|---|---|---|---|---|
| 1 | North Las Vegas | A | 98/100 | 1 | 376,515 |
| 2 | Laughlin | A | 97/100 | 1 | 9,000 |
Most Common Contaminants in Nevada
| Contaminant | Category | Violations | ZIPs Affected | Health Risk |
|---|---|---|---|---|
| Surface Water Treatment Rule | Treatment Technique | 119 | 103 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 100 | 94 | No |
| Lead | Inorganic | 89 | 73 | No |
| Contaminant 0700 | Other | 81 | 80 | Yes |
| Revised Total Coliform Rule | Microbiological | 62 | 13 | No |
| Stage 1 DBP Rule | Treatment Technique | 23 | 13 | No |
| Stage 2 DBP Rule | Treatment Technique | 18 | 8 | Yes |
| Barium | Inorganic | 16 | 10 | Yes |
| Combined Radium | Radionuclides | 15 | 10 | Yes |
| E. coli | Microbiological | 6 | 3 | No |
Water Quality Overview
Nevada has 165 community water systems serving approximately 5,732,599 people across 254 ZIP codes. These systems have accumulated 691 EPA violations, including 122 health-based violations.
Health-based violations account for 18% of all violations in Nevada. These violations indicate contaminant levels that may pose direct risks to human health, as opposed to monitoring or reporting failures.
Violation Breakdown
| Violation Type | Count | Percentage |
|---|---|---|
| Health-based | 122 | 17.7% |
| Monitoring/Reporting | 569 | 82.3% |
| Total | 691 | 100% |
Health-based violations indicate contaminant levels exceeding EPA Maximum Contaminant Levels (MCLs). Monitoring violations indicate failures to test or report — these do not necessarily mean unsafe water, but they mean the water was not properly verified.
Cities with Most Violations
The following cities in Nevada have the highest number of EPA violations:
| Rank | City | Grade | Violations | Water Systems | Population |
|---|---|---|---|---|---|
| 1 | Las Vegas | A | 308 | 5 | 1,563,833 |
| 2 | Reno | B | 48 | 5 | 454,618 |
| 3 | Elko | B | 24 | 5 | 23,659 |
| 4 | Gerlach | C | 24 | 2 | 530 |
| 5 | Boulder City | A | 22 | 4 | 16,214 |
| 6 | Empire | B | 22 | 1 | 350 |
| 7 | Battle Mountain | C | 19 | 2 | 3,985 |
| 8 | Sparks | B | 18 | 2 | 1,345 |
| 9 | Austin | C | 17 | 2 | 700 |
| 10 | Goldfield | B | 14 | 2 | 488 |
Violation counts are cumulative across all water systems serving each city. Higher counts may reflect larger systems with more monitoring requirements, not necessarily worse water quality.
Cities with Best Water Quality
These Nevada cities maintain Grade A water with zero violations:
| Rank | City | Grade | Score | Water Systems | Population |
|---|---|---|---|---|---|
| 1 | North Las Vegas | A | 98/100 | 1 | 376,515 |
| 2 | Laughlin | A | 97/100 | 1 | 9,000 |
Violation Trend Over Time
Year-by-year EPA violations recorded across all water systems in Nevada:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2021 | 13 | 13 |
| 2022 | 24 | 24 |
| 2023 | 17 | 17 |
| 2024 | 35 | 35 |
| 2025 | 118 | 118 |
Violations have increased from 13 in 2021 to 118 in 2025. This trend warrants monitoring and may reflect expanded testing requirements rather than worsening quality.
Most Common Contaminants
The following contaminants have caused the most violations across Nevada water systems:
| Contaminant | Category | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|
| Surface Water Treatment Rule | Treatment Technique | 119 | 103 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 100 | 94 | No |
| Lead | Inorganic | 89 | 73 | No |
| Revised Total Coliform Rule | Microbiological | 62 | 13 | No |
| Stage 1 DBP Rule | Treatment Technique | 23 | 13 | No |
| Stage 2 DBP Rule | Treatment Technique | 18 | 8 | Yes |
| Barium | Inorganic | 16 | 10 | Yes |
| Combined Radium | Radionuclides | 15 | 10 | Yes |
| E. coli | Microbiological | 6 | 3 | No |
| Atrazine | Organic | 5 | 5 | No |
How to Check Your Water in Nevada
Enter your ZIP code on ZipCheckup for detailed water system data including contaminant levels, violation history, and safety scores
Request your CCR — every water utility must provide an annual Consumer Confidence Report
Get a home test — certified kits ($20-$50) or professional lab tests ($150-$400)
Consider filtration — NSF-certified filters can address specific contaminants found in your area
EPA Enforcement
The EPA and state regulators have taken 1,941 enforcement actions against water systems in Nevada. Enforcement actions range from compliance assistance to formal orders and penalties.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Enforcement: EPA ECHO
Updated daily.
What are EPA violations?
Health-based violations mean a contaminant was detected above the EPA's Maximum Contaminant Level (MCL) — the legal limit designed to protect human health. Nevada has 122 such violations across its water systems. Not all violations cause illness, but repeated exceedances increase risk, especially for children and immunocompromised individuals.
Understanding water quality grades
ZipCheckup grades water systems from A to F based on EPA violation history, contaminant levels, and system compliance. Grade A means few or no violations; Grade F indicates persistent or serious issues. Grades are calculated per ZIP code and aggregated at the city, county, and state level.
Wondering about your tap water?
Water quality varies by ZIP code. Enter yours to see contaminant data, violations, and filtration recommendations specific to your area.
Check Your ZIP Code Water Quality →Frequently Asked Questions
Is the tap water safe to drink in Nevada?
Nevada has 165 community water systems with 691 recorded EPA violations, including 122 health-based. Water quality varies by city and ZIP code — check your specific location for detailed results.
How many water violations does Nevada have?
Nevada has 691 total EPA violations across 254 ZIP codes. 122 are health-based violations that indicate contaminant levels potentially harmful to human health. The remainder are monitoring or reporting violations.
Which city in Nevada has the worst water quality?
Las Vegas, NV has the most EPA violations among major cities in Nevada with 308 recorded violations. Check individual ZIP codes for the most accurate picture of your local water quality.
Which city in Nevada has the best water quality?
North Las Vegas, NV ranks among the best for water quality in Nevada with a grade of A. Multiple cities in Nevada maintain strong EPA compliance records.
What contaminants are found in Nevada drinking water?
Nevada water systems are monitored for over 90 EPA-regulated contaminants including lead, copper, nitrates, disinfection byproducts, and bacteria. The most common violations vary by region — check your ZIP code for contaminant-specific data.