Thousands of hazardous sites along the U.S. coast face the threat of flooding by 2100 due to rising sea levels, putting nearby communities at serious health risk, a new study reveals. The research found that 5,500 locations—handling sewage, trash, oil, gas, and other dangerous materials—could be underwater if carbon emissions continue unchecked. Many of these spots are already on track to flood sooner, with over half expected to face risk by 2050.
The study highlights a worrying pattern: low-income and marginalized communities, including many people of color, are the most vulnerable to these flooding risks. But there is some hope. The researchers noted that even modest cuts to greenhouse gas emissions could reduce the number of at-risk sites by about 300 by the end of the century.
Lara J. Cushing from UCLA, one of the scientists behind the study, said their aim was to look far ahead to help communities prepare and build resilience. Funded by the Environmental Protection Agency, the research builds on earlier California-focused work and uses data from 23 coastal states and Puerto Rico.
Sea levels are rising faster than before due to melting glaciers and ice sheets, plus the ocean water expanding as it warms. Some areas along the U.S. coast are also sinking due to erosion and groundwater pumping, making flooding risks worse, according to NOAA.
The study mapped out hazardous sites near the coast and used sea level projections for 2050 and 2100 to estimate flooding chances under different emissions scenarios. It considered communities living within a one-kilometer radius of high-risk sites and found clear links to social and economic factors affecting those residents.
Most of the threatened sites fall into four categories: fossil fuel ports and terminals (44%), power plants (30%), refineries (24%), and coastal sewage treatment plants (22%). Nearly 80% of these locations are clustered in seven states—Louisiana, Florida, New Jersey, Texas, California, New York, and Massachusetts.
Experts warn that flooding near these industrial sites could expose people to dangerous toxins, bacteria like E. coli, heavy metals, and harmful chemicals. These exposures might cause illnesses ranging from stomach issues to long-term problems like organ damage or cancer, especially for those with existing health conditions.
Thomas Chandler of Columbia University called the study a crucial wake-up call for policymakers and governments. He stressed the need for stronger investment in hazard mitigation, climate risk assessments, and resilience planning to protect vulnerable communities.
The study did not include oil and gas pipelines or account for more severe storms in the future, meaning some risks might be underestimated. However, past hurricanes like Katrina and Harvey have already shown how flooding near such infrastructure can cause toxic spills.
With climate change steadily pushing sea levels higher, scientists and officials say it’s urgent to act now to reduce emissions and prepare coastal areas. Doing so could lessen the damage and health risks before they become unavoidable.