More than two dozen storage tanks holding crude oil, gasoline, and other contaminants ruptured or otherwise failed when Harvey slammed into the Texas coast, spilling at least 145,000 gallons of fuel and spewing toxic pollutants into the air, per an AP analysis of pollution reports submitted to state and federal regulators. The tank failures follow years of warnings that the Houston area's petrochemical industry was ill-prepared for a major storm, with about one-third of the 4,500 storage tanks along the Houston Ship Channel located in areas susceptible to flooding, researchers say. The tanks are prone to float and break during floods, and Harvey's unprecedented rainfalls revealed a new vulnerability when the roofs of some storage tanks sank under the weight of so much water. An expert notes the storm surge was small enough, though, that refineries seem to have avoided the huge spills tied to storms like Hurricane Katrina, when ruptured tanks released several millions of gallons of oil.
The reports also say air pollutants such as benzene, toluene, and xylene were released into the atmosphere. Long-term exposure to such pollutants can cause cancer, although Texas officials say they never reached concentrations high enough in the storm's wake to cause health concerns. More massive storage tanks could be put to the test in coming days as Hurricane Irma bears down on Florida. Although Florida has no oil refineries, it has more than 20 petroleum product storage terminals in coastal communities and about 30 chemical companies with a presence in the state, including a significant number of facilities in the Tampa Bay area, per the American Chemistry Council and US Energy Information Administration. "Tampa Bay is one of the most vulnerable cities in the country" to hurricanes, says one expert. (Read more Hurricane Harvey stories.)