After Hurricanes Helene and Milton, Bacteria and Chemicals May Lurk in Flood Waters

Florida residents are returning to their homes to start picking up the pieces after Hurricane Milton carved a destructive path through the Gulf Coast. 

The storm would have been far worse if not for some lucky breaks on wind shear and where it made landfall. But damage is widespread, which my colleagues reported earlier today. Houses are gutted, felled trees and debris line the streets and more than 2 million people were still experiencing power outages as of late morning Friday. At least 17 people died during the storm and its aftermath, The Tampa Bay Times reports.

Over the past few weeks, Hurricane Helene and now Hurricane Milton have also caused widespread flooding in the regions they hit. Though the storms have cleared, there are different threats that linger in the water left behind. Research shows that toxic chemicals, bacteria from sewage and debris mixed into flood water during storms can pose severe health risks to hurricane survivors long after the rain stops. 

Industrial Site Overflow: During Hurricane Helene’s watery assault at the end of September, several industrial sites flooded across the southeast, including a plastics factory in Tennessee. Hurricane Milton’s path directly cut through an area with more than 100 facilities containing industrial waste, from phosphate fertilizer companies to power plants with coal ash ponds. 

Officials are still assessing whether potential breaches at these facilities leaked into flood water or the air at hazardous levels, which could cause a variety of health impacts in residents in the area depending on the type of pollution. It’s a common problem during storms across the U.S.—and one likely getting worse with climate change, researchers say. 

From 2005 to 2020, two to three times as many excess releases of hazardous waste were reported during hurricanes in the Texas Gulf Coast than “business-as-usual periods,” according to a study published in July. Researchers at Rice University in Texas recently created an interactive map showing where active toxic industrial facilities will be most threatened by future floods using data from climate modeling company First Street Foundation. 

They found that communities most at risk for contamination are in the northeastern U.S. and Texas Gulf, which boasts an abundant network of oil refineries and petrochemical plants. During Hurricane Harvey in 2017, flooding caused more than 100 industrial spills in and around Houston that released hundreds of millions of gallons of wastewater and chemicals—some cancer-causing—into the surrounding area. 

In some cases, communities are not informed when a breach occurs because the U.S. Environmental Protection Agency requires little information from companies about chemical risks, Rice University researchers wrote in a recent article for The Conversation. 

“We believe this limited public information on rising chemical threats from our changing climate should be front-page news every hurricane season,” they wrote. “Communities should be aware of the risks of hosting vulnerable industrial infrastructure, particularly as rising global temperatures increase the risk of extreme downpours and powerful hurricanes.” 

Wading Through Wastewater: Another ingredient often mixed into the murky soup of post-hurricane water? Sewage—and lots of it. Flooding from Milton shorted a backup generator at a wastewater treatment plant in the Florida city of Leesburg, causing nearly 2 million gallons of untreated sewage to spill onto the streets early Thursday. Other areas across the Florida Gulf Coast and western North Carolina saw similar overflows during the back-to-back hurricanes, Bloomberg reports.  

Last week, my colleague Lisa Sorg wrote about how this contaminated water could contain harmful bacteria such as E. coli, which can contaminate private water wells in North Carolina. Effluent from animals on farms also seeps into waterways after storms, a growing problem as the livestock industry continues to expand, my colleague Georgina Gustin reports. 

“We’re seeing way more rain in shorter amounts of time, and there’s simply not enough time for the ground or waterways to absorb this much water,” Sarah Graddy, a spokesperson for the Environmental Working Group, which tracks the climate and environmental impacts of large-scale farms, told Inside Climate News. “It’s inundating operations that are rife with contaminants and effluents that are toxic to people, and the waste is getting into our streams, rivers and private wells.”

Storms frequently overwhelm wastewater treatment plants across the U.S., many of which are outdated and understaffed. For example, in February, I wrote about how the atmospheric rivers that drenched California inundated communities throughout San Diego with billions of gallons of untreated wastewater from the Tijuana River Valley. 

The dilapidated sewage treatment plants at the border in this area are commonly flooded, even during minor rain events. The Centers for Disease Control and Prevention are currently investigating the health impacts of this Tijuana River sewage crisis, which doctors believe is causing an uptick in gastrointestinal diseases. 

Back in Florida, the state’s Department of Health issued an advisory on Tuesday warning residents to avoid flood waters to prevent exposure to a harmful bacteria known as Vibrio Vulnificus. The pathogen thrives in the brackish water left behind by storms and can cause skin infections or, in severe cases, death. Several communities in western North Carolina are still under a boil water advisory after Hurricane Helene, which was more than two weeks ago. 

“Floodwater with sewage or other harmful contaminants in it can lead to infectious diseases, particularly among people who are already ill, immunocompromised or have open wounds,” Jennifer Horney, a professor of epidemiology at the University of Delaware, wrote in The Conversation. “Even after the water recedes, residents may underestimate the potential for contamination.”

More Top Climate News 

Average wildlife population sizes have declined by roughly 73 percent from 1970 to 2020, suggests a new report published by the World Wildlife Fund and the Zoological Society of London. The Living Planet Index compiles data from nearly 5,500 species around the world and shows that animals living in rivers and lakes have seen the greatest declines. However, some researchers have criticized the report, saying that there is not enough data available to make a confident estimate of overall biodiversity loss, Catrin Einhorn reports for The New York Times. 

The U.S. government’s Defense Advanced Research Projects Agency is funding several projects aimed at building “hybrid” reefs partially made of oyster or corals to help protect coastlines from hurricanes, Saqib Rahim reports for Wired. Research shows that coral reefs provide crucial “living barriers” that protect coastal communities from storm surge and sea-level rise, which I wrote about in May. Now, scientists are increasingly exploring how to scale up this approach by combining natural reef or oyster ecosystems with human infrastructure. 

A federal judge ruled on Thursday that the state of Georgia is not required to reopen voter registration despite disruptions caused by Hurricane Helene. The judge’s verbal ruling stated that the three groups that sued for an extension did not adequately prove that the storm disrupted registration before the voter deadline, Jeff Amy reports for The Associated Press. Grist’s Zoya Teirstein recently explored other ways that Helene may affect the upcoming presidential election in key battleground states, if you want to read more. 

Public libraries are increasingly used as refuges for survivors of extreme weather events, Patrick Sisson writes for Fast Company. After Helene hit the North Carolina city of Asheville, hundreds of locals showed up at the West Asheville Public Library to access one of the few working Wi-Fi hotspots in the area, as well as coordinate meeting spots or charge their phones using a rare bit of electricity available amid widespread blackouts. Similar trends are happening in the face of climate-driven wildfires, heat waves and other storms. 

Due to an impending budget cut, the U.S. Forest Service is slashing its seasonal workforce next summer, which experts say could have cascading negative impacts on public lands, Nick Bowlin reports for High Country News and Vox. The cuts will not affect temporary wildland firefighting positions, but stand to eliminate the “large, often underappreciated army of seasonal or temporary workers who clean bathrooms and campgrounds, empty trash cans, maintain trails, welcome people at visitor centers and do critical research work on the environment,” Bowlin writes.