10 States With the Worst Tap Water Quality, According to Residents

Few things are as refreshing as a cool glass of water on a hot summer day. But how good is the water that comes out of your faucet?

In some states, the answer is unlikely to be reassuring.

Recently, J.D. Power gathered feedback from water utility customers in states across the nation. It asked these customers to rate the quality and reliability of their water utility. The states that qualified for the rankings have a water utility that serves a minimum of 400,000 residential customers and had a minimum 100 survey respondents.

With that criteria in mind, these are the states that have the worst tap water quality based on customer rankings on a scale from 100 (worst) to 1,000 (best). We’ll start with the best of the worst.

Indiana

This state’s tap water score from J.D. Power: 756 out of 1,000 possible points

Indiana’s rivers, reservoirs and groundwater serve as the source of public drinking water in the state. Unfortunately, these resources are all sensitive to pollution problems.

In a 2015 survey, 80% of Indiana drinking water utilities acknowledged struggles with poor quality source water, according to the Hoosier Environmental Council.

Arizona

This state’s tap water score from J.D. Power: 750 out of 1,000 possible points

Local geology plays a role in the quality of the water in Arizona’s aquifers. The state has large deposits of salt, which has resulted in groundwater with high levels of sodium, chloride, calcium, magnesium, sulfates and carbonates, according to the University of Arizona.

Mississippi

This state’s tap water score from J.D. Power: 750 out of 1,000 possible points

Last summer, Jackson, Mississippi, became the poster child for low-quality drinking water. Years of problems with the water system combined with heavy rains in 2022 to make the water potentially unsafe to drink.

Ohio

This state’s tap water score from J.D. Power: 748 out of 1,000 possible points

A 2021 report from the Ohio Environmental Protection Agency found that so-called “forever chemicals” had contaminated more than 100 public water systems in the state.

These manmade chemicals — known as PFAS, which stands for per- and polyfluoroalkyl substances — are known to be toxic and virtually indestructible.

Pennsylvania

This state’s tap water score from J.D. Power: 748 out of 1,000 possible points

One-third — 33% — of Pennsylvania’s waterways are polluted, according to a report from Pennsylvania’s Department of Environmental Protection. That reality potentially impacts the quality of drinking water in the state, among other things.

Texas

This state’s tap water score from J.D. Power: 737 out of 1,000 possible points

Earlier this year, the nonprofit Texas Water Trade surveyed 650 households in low-income Texas communities and found that 61% of residents do not think their water is safe to drink.

New Mexico

This state’s tap water score from J.D. Power: 731 out of 1,000 possible points

The New Mexico Environment Department notes that several chemical contaminants pose potential problems to drinking water in the state, including arsenic, uranium, nitrate and fluoride.

Oklahoma

This state’s tap water score from J.D. Power: 726 out of 1,000 possible points

As in virtually all states, Oklahoma groundwater is at risk from some types of natural contaminants. For example, in central Oklahoma, metals such as arsenic, chromium, selenium and uranium pose a potential threat.

Maryland

This state’s tap water score from J.D. Power: 721 out of 1,000 possible points

Recent studies in Maryland have detected the presence of microbiological contaminants — including total coliforms and E. coli — in some drinking water. Levels of “forever chemicals” also have been noted.

Alabama

This state’s tap water score from J.D. Power: 701 out of 1,000 possible points

The situation regarding the safety of drinking water in Alabama is a little confusing. In late 2022, the Birmingham Water Works Board sued a group of chemical companies, accusing them of creating chemicals that contaminated the water supply.

Yet, earlier this year, the same board insisted that local water was safe to drink. Shortly after issuing that statement, the board decided to drop the lawsuit against the chemical companies. The board said subsequent testing found contamination levels far below the danger zone.