The best and worst U.S. states for tap water have been ranked, with Washington topping the list and Arizona coming in last.

A 2022 Gallup poll showed that 57% of Americans are more concerned about safe drinking water than global warming, air pollution, or the extinction of animal species.

Since 2012, the combined water and sewer bill for a typical household in the U.S. has increased 54.8%, and 41% of customers say they do not feel the water provided by their local utility is safe to drink, according to J.D. Power.

J.D. Power ranked the states with the best and worst tap water based on its U.S. Water Utility Residential Customer Satisfaction Study, which measures satisfaction among residential customers from 92 water utilities, or companies, around the U.S. that deliver water to populations of at least 400,000.

Customers rated the quality of water based on taste, color, odor, hardness, and other factors on a scale of one to 10, with one being unacceptable and 10 being outstanding. The ranking of states was based on responses from 32,833 residential water utility customers from June 2023 through March 2024.

J.D. Power's utilities intelligence director, Ramah Vaughn, explains to CNBC Make It that this year's study is distinct from previous ones. While past studies centered on customers' evaluations of water's reliability and quality, the current study solely concentrates on water quality.

10 U.S. states with the best tap water

1. Washington
2. Kansas
3. Hawaii
4. Kentucky
5. Massachusetts
6. New York
7. Connecticut
8. Georgia
9. Louisiana
10. Virginia

According to J.D. Power, 84.5% of customers gave positive marks to Washington's tap water, making it the state with the best tap water.

"Washington has been able to provide a premium product without complaints about taste and smell, meeting customers' expectations of what clean fresh water should look like," Vaughn says. "Customers in Washington are extremely pleased with the quality of the product."

In 2021, the state launched a program to address the per-and-polyfluoroalkyl substances, or PFAS, found in its drinking water. In 2023, the Washington State Department of Health introduced a dashboard to inform people if their tap water had been contaminated with "forever chemicals."

In response to J.D. Power's research, Washington declared it would establish a drinking water standard exceeding the EPA's PFAS regulation to further minimize public exposure to "forever chemicals."

10 U.S. states with the worst tap water

1. Arizona
2. New Mexico
3. Alabama
4. Oklahoma
5. Indiana
6. Nevada
7. Maryland
8. Wisconsin
9. Texas
10. California

According to the report, Arizona has the lowest favorability score of 62.6% when it comes to tap water in America.

"Arizona customers expressed dissatisfaction with the hardness of the water, stating that it is causing damage to pipes, leaving residue on shower walls, and emitting an unpleasant odor and color."

The U.S. Geological Survey states that the harder the water, the greater the amount of dissolved calcium and magnesium it contains.

Several states in the country's South, including Arizona, have some of the worst tap water, indicating a need for a lot of work to be done in these areas, says Vaughn.

The southern states that are underperforming are not the only ones, as Georgia and Louisiana are exceptions, ranking No. 8 and No. 9, respectively, on this year's best list.

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