The U.S. Chemical Safety Board is warning that many industrial sites where hazardous materials are stored may not be adequately prepared for extreme weather events.
A dayslong chemical fire outside of Houston during Hurricane Harvey erupted because the plant's owner never anticipated the worst-case scenario that played out in August as historic rainfall swamped its facility, the federal investigator said Wednesday.
French chemical maker Arkema SA had a disaster plan in place for its Crosby, Texas, plant located 25 miles from downtown Houston, but it didn't anticipate 6 feet of floodwater. Flooding caused the site's main electrical source to fail and then forced workers to shut off emergency power generators. Without refrigeration systems to cool the organic peroxides manufactured at the plant, the compounds became unstable and ignited.
The Arkema disaster should be a lesson to other chemical and industrial plants that urgently need to reassess their flood planning, lead investigator Mark Wingard said.
Vanessa Sutherland, chairwoman of the Chemical Safety Board, said Harvey showed that more extreme storms are possible and industrial sites need to re-evaluate how they prepare for flooding and test their worst-case assumptions.
"Facilities on the Gulf must reassess," she said. "Plan and plan again."
Even 3 feet of flooding would have caused the Arkema plant to lose power, making its hazardous materials unstable, the agency said. Arkema produces organic peroxides at the site, which are used to make plastic resins, PVC, fiberglass and other building materials.
When off refrigeration, organic peroxides degrade and become a fire hazard. As the storm hovered over the Houston area, workers moved the compounds from powerless warehouses to nine refrigerated trailers at the site, the Chemical Safety Board said. Within a day those trailers flooded and the power failed, causing the peroxides to explode.
Arkema has said it was impossible to predict the historic rainfall and flooding caused by Harvey, which exceeded even a 500-year flooding event. A spokeswoman said the company would continue to cooperate with the investigation.
The Chemical Safety Board is an independent investigating agency but doesn't have the authority to impose fines or force companies to change their practices. The board stopped short of issuing any formal recommendations to Arkema because its investigation is ongoing.
As the trailers caught fire sending dark plumes of smoke billowing into the sky, local authorities evacuated residents within a 1.5-mile radius and emergency responders set the remaining trailers on fire to speed up the process.
No one was killed during the fire, but seven first responders have sued Arkema, alleging they were exposed to dangerous fumes and hospitalized because the company didn't properly prepare for the power outage. Arkema has denied the allegations.
A new Massachusetts Institute of Technology study suggests that looking at historical records of extreme rainfall won't provide much insight into the future because high-intensity storms are increasing in frequency.
The MIT study, published in the Proceedings of the National Academy of Sciences, said that Houston-and Texas in general-will face an increasing risk of devastating rainfall. Texas had a 1% chance of experiencing Harvey-scale rainfall for any given year between 1981 and 2000, the study said. That risk could rise to 18% by the end of the century if greenhouse-gas emissions continue to rise. Those emissions help warm offshore waters-a phenomenon that can magnify the severity of storms and generate more rain, creating bigger floods, the authors said.