Less than 20 percent of a 461,000-gallon (1.7-million-liter) gasoline spill in Texas during Hurricane Harvey was recovered by the company responsible, while the rest evaporated or soaked into the ground, a U.S. Coast Guard official said Thursday.
Only a minor amount of the spill appeared to have escaped past containment berms at the Magellan Midstream Partners storage tank farm in the Houston suburb of Galena Park, said Coast Guard Lt. Commander Jarod Toczko. It's the largest spill reported to date from the storm that made landfall in Texas last month.
The Oklahoma-based company reported recovering about 2,000 barrels, or 84,000 gallons (320,000 liters), of gasoline in the days after the Aug. 31 spill, Toczko said. It's unknown how much of the fuel evaporated and how much seeped into the ground.
"We know how much spilled, but it's difficult to say the exact amount evaporated," he said.
Gasoline is more volatile than oil, meaning it evaporates more quickly after it's spilled. It's also more likely to catch fire and can more rapidly penetrate the soil and potentially contaminate groundwater.
Magellan spokesman Bruce Heine says a cleanup of contaminated soil at the company's facility should be completed within a few weeks. He estimated that less than five gallons (19 liters) of fuel reached a small waterway adjacent to the company's property that drains into the Houston Ship Channel. The rest was contained onsite.
"Although we do not have an estimate of the total volume of soil that we will remove and replace at this time, the project will comply with all laws and regulations," Heine said.
State officials were not aware of any health concerns from the spill, according to Texas Commission of Environmental Quality spokeswoman Andrea Morrow.
Environmentalists have criticized the official response to the accident, including not notifying the public more quickly about the scale of the spill.
Magellan reported the total volume to federal officials on Sept 5. A day later, a U.S. Environmental Protection Agency official told The Associated Press that the spill was a "2,500-gallon fuel oil spill at the Houston Magellan facility."
The volume was not publicly reported until Sept. 11, in a story by the AP. The EPA said in a statement this week it "provided "the best information it had at the time" when it used the lower figure.
The AP has identified at least 34 above ground fuel storage tanks and tank batteries that failed during Harvey and released more than 600,000 gallons (2.2 million liters) combined of crude oil, gasoline and other chemicals.
Two storage tanks failed in the Magellan case. Initial indications suggested the massive tanks floated off their foundations as floodwaters swamped the company's tank farm, Toczko said. That's what happened at tank farms in Louisiana during Hurricane Katrina, when numerous storage tank failures spilled millions of gallons of fuel into floodwaters.
Magellan has said only that the spill was "related to flooding associated with the hurricane." Heine said Thursday that the cause remained under investigation.