The EPA said Valero is preparing a new report that will show a ‘substantial increase’ in emissions.
Defense Fund previously detected a plume of benzene near homes and businesses that was nearly twice the state limits for short-term exposure.
Benzene is a carcinogenic component of crude oil and gasoline. Breathing it can cause dizziness, headaches and even unconsciousness.
The benzene release by the Valero refinery was the strongest concentration of toxic compounds detected by independent air monitoring throughout the Houston area in the aftermath of Harvey, although there were elevated levels also detected in cities like Baytown and Port Arthur. The 324 parts per billion is nearly double the state’s allowable amount of 180 parts per billion for short-term exposure.
“Based upon the volume of
material in the tank at the time of the roof failure, EPA estimates that the emissions from the tank were highest immediately following the roof failure and have diminished over time due to efforts by the company to remove tank contents, ” the EPA said.
Valero also spread foam on the chemicals to minimize emissions.
“Moderate” emissions releases were still being detected by the EPA as recently as Sept. 8 at the 190foot wide storage tank.
Valero told the EPA it was removing residual crude oil from the tank using pumps and evaluating safe methods to remove the tank’s crumpled roof.
Last week, Valero spokeswoman Lillian Riojas credited the Valero crew members with quickly containing the oil that leaked from the roof drain at the refinery.
She noted the U.S. Coast Guard inspected the cleanup, and, she said, Valero is working with the state and the EPA “on monitoring for any potential emissions from the oil.”
The Valero refinery, seen in 2014, is in the Manchester neighborhood of east Houston.