The 10 American Cities With the Most Contaminated Water

Who under the age of 40 can forget the Flint water crisis — and its astonishing duration? Once one of America’s great industrial cities, Flint had fallen on hard times and lost a significant portion of its population.

From 2014 to 2019, the city struggled with lead contamination in its water supply and a possible outbreak of Legionella bacteria. Jamie Gaskin, CEO of the United Way of Genesee County, stated that “We know between 6,000 and 12,000 kids, somewhere in there, have been exposed in this period of time to lead.”

A series of lawsuits eventually settled for an enormous sum. MLive reported that “Children 6 years old and younger during the Flint water crisis are the biggest potential beneficiaries of a historic $600-million settlement with the state of Michigan.” This settlement was reached in 2020.

Although cities are often singled out as places where drinking water can be unsafe, the problem is far more widespread across America than most people would assume. According to the Environmental Working Group, new data released by the EPA shows that an additional 6.5 million Americans have drinking water contaminated by the toxic “forever chemicals” known as PFAS, bringing the total number of people at risk to approximately 165 million across the country.

A review conducted by Climate Crisis 247 to identify cities with the “dirtiest” drinking water draws on several sources, including the latest EWG data covering contaminant levels such as arsenic, lead, PFAS, and chromium-6, as well as Militpure data compiled at the state level, APEC Water, LifeSource Water,  247WallSt,and the EPA. There was considerable overlap across these lists.

LifeSource noted that cities with the worst water quality often face challenges from aging infrastructure, environmental contamination, or naturally occurring minerals. While U.S. tap water is regulated, quality can vary significantly by city and even by neighborhood — and water quality in urban areas is frequently worse than in rural or suburban ones, due to denser populations, higher concentrations of industry, and increased pollution.

Remarkably little has been done to address these problems. The Seven Seas Water Group observed that while the water systems in each affected city face very different pressures, they share one thing in common: they are being stretched to their limit, putting ongoing supply at risk. Some are dealing with aging and undermaintained infrastructure, while others are overwhelmed by the effects of climate change or population growth. Deferred maintenance, chronic underinvestment, outdated infrastructure, and leadership gaps continue to plague water systems across the board.

The analysis of “dirty” water is based on the presence and levels of contaminants such as PFAS, arsenic, lead, and disinfection byproducts.

The 10 American Cities with the Dirtiest Water

1. Houston, TX — Dangerously elevated arsenic levels, plus a range of other toxins from groundwater contamination.
2. Newark, NJ — Lead pipes, haloacetic acids, and ongoing regulatory violations.
3. Flint, MI — Lead contamination continues to haunt the system, even years after the crisis.
4. Jackson, MS — Bacterial contamination, pressure failures, and episodes of discolored water.
5. Pittsburgh, PA — Aging lead lines and industrial residue.
6. Baltimore, MD — Elevated disinfection byproducts and persistent lead risks.
7. Detroit, MI — Aging pipes and concerns over chromium-6 levels.
8. Los Angeles, CA — Nitrates, arsenic, and contamination from wildfire runoff.
9. Chicago, IL — Lead service lines concentrated in older neighborhoods.
10. Cleveland, OH — Legacy lead contamination compounded by industrial pollution.

Cities in Texas, New York, California, and the Midwest dominate the list, with Houston leading for arsenic levels, Flint for lingering lead, and Newark and Baltimore for regulatory violations and decaying infrastructure. Aging pipes, industrial runoff, and the growing impact of wildfires continue to amplify risks nationwide. The takeaway is straightforward: test your tap water, use filters, and recognize that this is a problem affecting millions of Americans.