Best & Worst Tap Water in the US: 2026 State Rankings

Which states have the cleanest tap water in America? Based on EPA violation data, contaminant levels, and water quality metrics, states like Hawaii, South Dakota, and Minnesota consistently rank at the top—while Texas, Pennsylvania, and Arizona face the most challenges.

This guide breaks down the complete state-by-state rankings, explains what makes water quality good or bad, and helps you understand what the data means for your tap.

The 10 States with the Best Tap Water

These states have the fewest EPA violations, lowest contaminant levels, and strongest water infrastructure:

Rank	State	Why It Ranks High
1	Hawaii	Only 2 water quality violations statewide; pristine aquifer sources
2	South Dakota	95% of public water meets all EPA standards; award-winning systems
3	Minnesota	Abundant lakes and aquifers; strong state oversight
4	Nebraska	Low population density; clean groundwater sources
5	Kentucky	Louisville Water trademarked its tap water for quality
6	Delaware	Small state with well-maintained infrastructure
7	Washington	Leading PFAS regulations; high customer satisfaction
8	Colorado	Rocky Mountain snowmelt provides clean source water
9	Tennessee	Diverse water sources; strong compliance record
10	Oregon	Protected watersheds; proactive contamination monitoring

What These States Do Right

The top-ranked states share several characteristics:

Protected source water: Hawaii draws from underground aquifers protected by volcanic rock. Colorado and Oregon benefit from mountain snowmelt. Minnesota's 10,000+ lakes provide abundant, clean surface water.

Strong infrastructure investment: Kentucky has invested heavily in water treatment, to the point where Louisville Water trademarked its product as "Louisville Pure Tap®"—something few utilities would dare attempt.

Proactive regulation: Washington State adopted PFAS standards stricter than federal requirements and launched a public dashboard showing contamination levels by area.

Low industrial impact: States like South Dakota and Nebraska have lower population density and less industrial activity that could contaminate water sources.

The 10 States with the Worst Tap Water

These states have the most EPA violations, aging infrastructure, or persistent contamination issues:

Rank	State	Primary Issues
50	Texas	23,628 violations; aging rural infrastructure
49	Pennsylvania	21,527 violations; legacy industrial contamination
48	Arizona	Very hard water (285+ ppm); customer complaints
47	West Virginia	8,490 violations; coal industry impact
46	Oklahoma	Aging systems; nitrate contamination
45	New Mexico	Arsenic in groundwater; drought stress
44	Alaska	Remote systems hard to maintain; septic issues
43	Louisiana	Industrial pollution; hurricane damage to systems
42	Ohio	Lead service lines; agricultural runoff
41	New York	Large number of systems; inconsistent quality

Why These States Struggle

Aging infrastructure: Texas and Pennsylvania have thousands of small water systems, many with pipes over 50 years old. Replacing lead service lines and upgrading treatment plants requires billions in investment.

Industrial legacy: West Virginia's coal industry and Louisiana's petrochemical corridor have left lasting impacts on water sources. Some contamination predates modern EPA regulations.

Geographic challenges: Arizona's water comes from the Colorado River and deep wells, both naturally high in minerals. Alaska's remote communities make system maintenance extremely difficult and expensive.

Agricultural runoff: Oklahoma and Ohio face nitrate contamination from farming operations, which can exceed safe levels in rural areas.

Important note: Being on this list doesn't mean the water is unsafe to drink. All public water systems must meet federal safety standards. Lower rankings indicate more violations, more reason to test your water, and potentially more benefit from home filtration.

How We Rank Water Quality

State water quality rankings come from several key sources:

EPA Violation Data

The EPA's Safe Drinking Water Information System (SDWIS) tracks every violation at every public water system in America. Violations include:

Health-based violations: Contaminants exceeding safe levels
Monitoring violations: Failure to test as required
Reporting violations: Late or missing reports
Treatment technique violations: Not treating water properly

States with more water systems naturally have more potential violations, which is why per-capita rates matter.

Contaminant Levels

The Environmental Working Group (EWG) tracks contaminant levels beyond just EPA limits, comparing them to health-based guidelines that are often stricter than legal requirements.

Common contaminants measured:

Lead and copper
Disinfection byproducts (THMs, HAAs)
Nitrates
PFAS ("forever chemicals")
Arsenic
Radium

Customer Satisfaction

J.D. Power surveys water utility customers on:

Water quality and taste
Reliability of service
Communication from utility
Billing accuracy
Conservation programs

This captures the human experience of water quality beyond just lab numbers.

Best Tap Water by Region

Water quality often follows regional patterns:

Pacific Northwest: Excellent

Seattle and Portland benefit from protected mountain watersheds and consistent rainfall. Both cities have soft water (under 30 ppm hardness) and minimal violations.

Upper Midwest: Very Good

Minnesota, Wisconsin, and the Dakotas have abundant freshwater resources and relatively low industrial impact. Cities like Minneapolis consistently rank well for water quality.

Rocky Mountains: Good

Denver and other Colorado cities get clean snowmelt water, though hardness can be moderate. Utah and Wyoming also benefit from mountain sources.

Northeast: Mixed

New York City actually has excellent water—NYC draws from protected Catskill reservoirs and has some of the softest water in the country (35 ppm). But other parts of the Northeast, especially Pennsylvania, struggle with aging systems.

Southwest: Challenging

Phoenix, Las Vegas, and other desert cities face very hard water (200-300+ ppm) and drought-stressed supplies. The Colorado River, which supplies much of the region, has naturally high mineral content.

Southeast: Variable

Some Southern states like Tennessee and Kentucky rank well, while Louisiana and parts of Florida face industrial or agricultural contamination challenges.

Texas: Highly Variable

Texas is huge, with over 7,000 water systems. Cities like Houston and Dallas have modern treatment plants and good water quality, but many rural systems struggle with compliance.

Cities with the Best Tap Water

While state rankings provide a broad picture, water quality ultimately varies city by city. These cities consistently rank among the best:

Top 10 Cities for Water Quality

Louisville, KY – Trademarked tap water; award-winning treatment
Seattle, WA – Protected Cedar River watershed; soft water
Portland, OR – Bull Run watershed; minimal treatment needed
Denver, CO – Rocky Mountain snowmelt; strong infrastructure
Minneapolis, MN – Mississippi River source; excellent treatment
New York City, NY – Catskill reservoirs; naturally soft water
San Francisco, CA – Hetch Hetchy reservoir; gravity-fed system
Boston, MA – Quabbin Reservoir; protected watershed
Honolulu, HI – Volcanic aquifers; pristine groundwater
Kansas City, MO – Missouri River source; modern treatment

What These Cities Share

Protected source water: Many draw from reservoirs in protected watersheds
Investment in infrastructure: Modern treatment plants and distribution systems
Proactive monitoring: Testing beyond minimum EPA requirements
Transparency: Easy public access to water quality reports

Cities with Water Quality Concerns

These cities have faced documented water quality challenges:

City	State	Primary Issue
Flint	MI	Lead crisis (ongoing remediation)
Newark	NJ	Lead service lines (replacement underway)
Jackson	MS	Infrastructure failures
Pittsburgh	PA	Lead pipes; aging system
Baltimore	MD	Aging infrastructure
Phoenix	AZ	Very hard water; taste complaints

Important context: Most of these cities are actively addressing their issues. Flint and Newark have replaced thousands of lead service lines. Jackson received federal funding for infrastructure repairs. Phoenix's water is safe—just very hard.

How to Check Your State's Water Quality

Step 1: Find Your Water Utility

Most Americans get water from a public system. Your utility is required to publish an annual Consumer Confidence Report (CCR) with test results.

Step 2: Read the CCR

Look for:

Detected contaminants and their levels
Violations in the past year
Water source (surface or groundwater)
Treatment methods used

Step 3: Use the EPA's Tools

EPA Drinking Water Dashboard: Search violations by state and utility
EWG Tap Water Database: Search by ZIP code for detailed contaminant data

Step 4: Test Your Home Water

Even in states with great water, your home's plumbing matters. Older homes may have:

Lead service lines (pre-1986)
Galvanized steel pipes that corrode
Lead solder in copper pipes

A home water test ($20-150) can identify issues specific to your plumbing.

Does State Ranking Really Matter?

Yes and no.

State rankings tell you about overall infrastructure quality and regulatory enforcement. If you're in a top-ranked state, you're less likely to encounter problems.

But water quality ultimately depends on:

Your specific water system: A poorly-maintained system in Minnesota can be worse than a well-run system in Texas
Your home's plumbing: Lead pipes affect water quality regardless of state
Your location within the state: Urban systems often differ dramatically from rural ones

Bottom line: Use state rankings as a starting point, then check your specific utility's reports and consider testing your home water for complete peace of mind.

What About Well Water?

Approximately 13 million American households rely on private wells, which aren't covered by EPA regulations or state rankings.

If you're on well water:

Test annually for bacteria, nitrates, and pH
Test every 3-5 years for heavy metals and other contaminants
Test after changes: flooding, nearby construction, or changes in taste/smell

Well water quality depends entirely on local geology and your well's construction—state rankings don't apply.

Improving Your Water Quality

Regardless of where you live, you can improve your tap water:

For Hard Water (Common in AZ, NV, FL, TX)

Water softener: Removes calcium and magnesium ($500-2,500 installed)
Reduces: Scale buildup, dry skin, spotted dishes

For Lead Concerns (Older homes, certain cities)

Reverse osmosis: Removes 95%+ of lead ($150-500)
NSF-certified pitcher filter: Affordable option ($20-40)
Run water before drinking: Flush pipes for 30 seconds each morning

For Taste and Odor Issues

Activated carbon filter: Removes chlorine taste and odors ($50-200)
Refrigerator pitcher: Simple solution for drinking water

For Comprehensive Protection

Whole-house filtration: Treats all water entering your home ($1,000-3,000)
Best for: Homes with multiple concerns or well water

Frequently Asked Questions

What state has the cleanest tap water?

Hawaii consistently ranks #1 with only 2 water quality violations statewide. The state benefits from pristine volcanic aquifers and limited industrial activity. South Dakota and Minnesota typically rank #2 and #3.

What state has the worst tap water?

Texas has the most total violations (23,628), followed by Pennsylvania (21,527). However, this partly reflects their large number of water systems. Arizona ranks lowest for customer satisfaction due to very hard water.

Is tap water in the US safe to drink?

Yes—all public water systems must meet EPA safety standards. The US has some of the safest tap water in the world. State rankings reflect relative quality differences, not safety concerns. Lower-ranked states may benefit more from home filtration, but their water still meets federal requirements.

Why does my state rank poorly?

Common reasons include: aging infrastructure, large number of small/rural systems, industrial legacy contamination, agricultural runoff, or naturally occurring minerals. Being in a lower-ranked state doesn't mean your specific water is bad—check your utility's reports.

Should I filter my water based on state ranking?

Consider filtration if: your state ranks in the bottom 15, your home was built before 1986, you're on a private well, or you notice taste/odor issues. Even in top-ranked states, home plumbing can affect water quality.

Check Your City's Water Quality

Want to know exactly what's in your tap water? We track EPA violation data, lead levels, and water hardness for thousands of US cities:

Cities in top-ranked states:

Seattle, WA – Soft water, minimal violations
Denver, CO – Mountain source, good quality
Minneapolis, MN – Lake source, well-treated

Cities actively improving:

Newark, NJ – Lead line replacement ongoing
Flint, MI – Infrastructure rebuilding
Phoenix, AZ – Hard water, but safe

Major metros:

Los Angeles, CA – Hard water (178 ppm)
New York City, NY – Soft water (35 ppm), excellent quality
Chicago, IL – Hard water (143 ppm), aging infrastructure
Houston, TX – Good quality despite state ranking

Search your city →

Methodology

This ranking combines data from:

EPA SDWIS: Water quality violations by state (2020-2025)
EWG Tap Water Database: Contaminant levels vs. health guidelines
J.D. Power: Customer satisfaction surveys (2023-2025)
USGS: Source water quality data

Violations were normalized by population and number of water systems. Contaminant data was weighted by public health significance. Rankings represent overall state performance—individual cities and systems vary significantly.

Sources: EPA Drinking Water Dashboard, Environmental Working Group, J.D. Power Water Utility Study, USGS Water Quality Portal. For the most accurate information about your specific water supply, review your utility's Consumer Confidence Report.