Superfund sites are some of the most polluted areas in the country, containing highly toxic waste such as asbestos, lead, and dioxin. Cleaning them up, which follows a systematic, science-based process as required by law, can take decades.There are more than 1,300 of these sites across the US, from Florida’s Panhandle to the banks of the Rio Grande in New Mexico. They’re found in nearly every state, often near residential areas. The EPA estimates that 78 million people live within three miles of a Superfund site—nearly 1 in 4 Americans.But these waste dumps face a growing threat: the worsening effects of climate change. The EPA has determined that more than 300 Superfund sites are at risk of flooding. The actual number of flood-prone sites, however, may be more than twice that amount, according to a 2021 Government Accountability Office report. Floodwaters can move toxic waste into neighboring communities, which threatens drinking water, agriculture, and broader ecosystem health.Read more at sciencefriday.comTranscripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.