Map Shows US Drinking Water Safety Issues by State

The U.S. has one of the safest water supplies in the world, according to the U.S. Centers for Disease Control and Prevention. However, contaminations and safety violations do still occur—with serious implications for public health.

The Safe Drinking Water Act (SDWA) of 1974, amended in 1996, was passed to protect public health in the U.S. by regulating the nation's public drinking water supply. To meet these standards, the Environmental Protection Agency (EPA) imposes limits on over 90 contaminants in drinking water, including chemical contaminants, like arsenic and lead, and microbial contaminants, like Giardia and Cryptosporidium.

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Failure to meet these limits results in an official "violation." And while the majority of recorded water safety violations are due to untimely water monitoring and reporting, thousands of health-related violations occur every year.

To explore how these violations vary across different states, Newsweek has compiled the data from the EPA's Enforcement and Compliance History Online for safe drinking water. Violations related to human health were counted for each state over the past five years, between 2019 and 2023. Using census data from July 2023, the violations per 100,000 people in each state and Washington, DC were calculated.

The results are as follows:

Per 100,000 people, the states with the most violations between 2019 and 2023 were:

1. Alaska 305 violations per 100,000
2. New Mexico 162
3. Louisiana 151
4. Oklahoma 127
5. Wyoming 103

Meanwhile, those with the fewest health-related violations during this period were:

1. Hawaii 0.6
2. Alabama 2
3. South Carolina 3
4. Tennessee 3
5. Washington, DC 4

Of course, the number of health-related violations does not necessarily equate to water quality. "The data reported to the EPA consists of violations of Safe Drinking Water Act regulations," a spokesperson from the EPA told Newsweek. "Compliance data reported to the EPA does not directly measure drinking water quality as this depends on violation type and other factors unique to each water system."

It is also worth noting that states like Alaska and Wyoming have relatively small populations for their size, meaning that there are more violations per person because there are simply fewer people. Indeed, if we look at absolute numbers, Texas has the highest number of health-based drinking water violations. However, it also has the second highest population in the U.S., so a lot more drinking water systems are needed (and therefore we would expect more violations due to the sheer quantity of water systems).

Despite its relatively small population, Alaska has been the subject of recent news due to the contamination of its rivers and streams with "milky orange" metal ores, thought to have been released from the thawing permafrost.

Meanwhile, the EPA has sent out a nationwide warning after recent federal inspections revealed 70 percent of U.S. water systems do not fully comply with SDWA standards, with many systems at risk of cyberattacks.

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