Drinking Water Report Card: Every US State Graded (2026)

We graded all 50 states on water quality, infrastructure, and regulatory compliance.

Methodology

Our grading system evaluates each state across four categories, weighted by their direct impact on what comes out of your tap. Contaminant levels (40%) measures the average concentrations of regulated contaminants -- lead, PFAS, nitrate, disinfection byproducts, and others -- across all cities we track in that state. Violation history (25%) counts how many EPA Safe Drinking Water Act violations the state's water systems have accumulated over the past five years.

Infrastructure condition (20%) factors in the age of the state's water distribution systems, lead service line prevalence, and water main break rates where data is available. Regulatory response (15%) evaluates how quickly state agencies address violations, whether they enforce penalties, and if the state has adopted standards stricter than federal minimums (as California and New Jersey have for several contaminants).

Each state receives an A through F letter grade. We used EPA SDWIS violation data, UCMR 5 monitoring results, state drinking water program reports, and American Society of Civil Engineers infrastructure assessments. States with fewer than 5 cities in our database are marked as "insufficient data" rather than graded.

Best States

States that score highest tend to share common traits: newer infrastructure, strong state-level regulation, and abundant clean water sources. Colorado, Oregon, and Minnesota consistently rank near the top, benefiting from mountain snowmelt and glacial aquifer sources that require less treatment. These states also have active state drinking water programs that go beyond federal minimums.

Massachusetts and Connecticut perform well despite older infrastructure because they have invested heavily in treatment upgrades and adopted aggressive lead remediation programs. New Jersey earns credit for setting its own PFAS limits years before the EPA acted, though its industrial legacy means contamination levels remain above average in some communities.

The common thread among top-scoring states is not geography alone -- it is political will. States that fund their drinking water programs adequately, enforce violations promptly, and proactively address emerging contaminants produce measurably better water outcomes for their residents.

Worst States

Texas, Florida, and Arizona score poorly due to a combination of rapid population growth, strained water supplies, and elevated PFAS and nitrate contamination. Texas has more Safe Drinking Water Act violations than any other state, driven by thousands of small water systems in rural areas that lack the funding and expertise to maintain compliance.

Mississippi ranks near the bottom, with Jackson's ongoing crisis as the most visible symptom of decades of statewide underinvestment. Louisiana and Oklahoma also score low, with high violation rates and aging infrastructure that receives minimal state funding.

Several Rust Belt states -- Ohio, Pennsylvania, and Illinois -- earn mediocre grades despite having adequate water sources. Their problem is infrastructure: these states have the highest concentrations of lead service lines in the country, a legacy of early 20th-century construction. Chicago alone has an estimated 400,000 lead service lines, more than any other US city.

Find Yours

State grades provide useful context, but they do not tell you what is coming out of your tap. Water quality varies enormously within a single state -- Portland, Oregon and a rural community 100 miles east can have completely different contaminant profiles, treatment systems, and infrastructure ages. A state with an "A" grade can still have individual cities with serious problems.

Search your city on CheckMyTap for specific data on lead, PFAS, hardness, nitrate, and other contaminants. We pull from EPA compliance data, UCMR 5 PFAS monitoring, and Lead and Copper Rule results to give you a complete picture of what your utility is delivering. If your city is not in our database, request your utility's Consumer Confidence Report -- they are required to publish one annually by July 1.

Regardless of where your state ranks, the pattern is consistent nationwide: utilities are legally required to meet minimum federal standards, but those standards have not kept pace with the science on contaminants like PFAS, chromium-6, and manganese. Knowing your specific numbers puts you in a position to take action where the regulations fall short.