Anchored in flood-prone areas in every state in the United States are more than 2,500 sites that handle toxic chemicals, a New York Times analysis of federal floodplain and industrial data shows. About 1,400 are in areas with the highest risk of flooding.
As the risk of flooding grows as a result of warming climates, there is a risk of more toxic spills like the one that hit Baytown, Texas, where Hurricane Harvey flooded a chemical plant, releasing bleach. Or like a Florida fertilizer plant that spilled phosphoric acid and an Ohio refinery that released benzene.
More than 2,500 sites that handle toxic chemicals are in flood-prone areas across the country.
The Houston area is home to more than 100 facilities that handle toxic chemicals and are located in flood zones.
Floods across the country are likely to worsen due to climate change, a comprehensive federal government scientific report warned last year. Heavy rains increase in intensity and frequency.
At the same time, rising sea levels combined with more frequent and extensive flooding caused by coastal storms such as hurricanes can increase the risk to chemical facilities near waterways.
The Times analysis looked at sites included in the Toxic Emissions Inventory, which covers more than 21,600 facilities nationwide that handle large amounts of toxic chemicals that are harmful to health or the environment.
Of those sites, more than 1,400 were in locations that the Federal Emergency Management Agency considers to be at high risk of flooding. An additional 1,100 sites were in moderate risk areas. Other industrial complexes lie just outside these defined flood hazard zones, obscuring their vulnerability as flood patterns change and expand.
The presence of chemical sites in areas vulnerable to flooding is a holdover from a time where the benefits to industry from proximity to rivers and oceans - for transportation and commerce, or for a cooling water supply - apparently outweigh risks.
"Water fronts are changing as a result of rising sea levels," said Jeanne Herb, an environmental policy expert at Rutgers University who has researched the hazards that weather-related floods pose to industries in New Jersey. . "In most cases, these facilities are in the water for a reason," he said. “So how do we make sure there are protections in place? That's the big question ".
Federal law does not explicitly require floodplain sites that handle toxic chemicals to take additional precautions against flooding. Nor do most states or local governments have such requirements.
President Barack Obama signed an executive order in 2015 requiring planners of federally funded buildings, roads and other infrastructure to account for the impact of potential flooding from rising sea levels or more extreme rainfall. President Trump rescinded those rules last year.
The Times analysis focused on the facilities of the federal toxic emissions database, which tracks sites that handle chemicals that could be harmful to health and the environment if released. The list does not include properties such as Superfund sites or sewage facilities, or chemical sites where the predominant hazards are fire or explosion, as opposed to toxic contamination.
The Times also examined reports of oil and chemical spills posted by the National Response Center, which is run by the Coast Guard. Companies are required by law to report spills to the N.R.C., although that database has been criticized as incomplete.
Still, the data provides insight into the thousands of spills that occur across the country each year.