The Valero refinery has been looked at from early on as the most likely culprit, since the massive refinery hugs Manchester's fence line, and, all things considered, the odds seem pretty high that Valero was one of the main sources of benzene and a slew of volatile organic compounds that were released into the air when rain sank the roofs of storage tanks on the property during Harvey, allowing all kinds of chemicals into the air that people are not supposed to inhale.
Valero acknowledged in a statement issued shortly after the accidental chemical release that something had gone wrong. But the company downplayed it, contending that officials "found no detectable levels of emissions in the community.”
While Valero isn't the only refinery or plant in the area, it is the closest by far, which makes the contention that there were no detectable emissions particularly questionable.
Juan Parras, the founder of Texas Environmental Advocacy Services, went through Manchester in the middle of Harvey and reported that the whole place smelled like a gas stove. "I was afraid to even light a match; I kept thinking everything would burst into flames if I did," Parras said.
We already knew that Valero and the other area plants and refineries along the Houston Ship Channel collectively released thousands of tons of pollutants into the air either during the hurricane or immediately after, but the Texas Commission on Environmental Quality reports apparently did not cover everything that escaped.
How do we know this? Because the federal Environmental Protection Agency's enforcement division recently swept in and demanded that records and maintenance histories regarding the storage tanks that leaked during the hurricane be handed over, demands that Valero is required to respond to.
The push for these records comes as EPA officials have also let it be known they believe Valero "significantly underestimated" the amount of benzene and other harmful compounds that leaked out of the refinery during the torrential downpours from Harvey.
Valero's initial estimates for the release during Harvey were fairly modest, with just over six pounds of benzene allegedly let loose in the atmosphere and about 3,350 pounds of unspecified substances released. However, EPA officials say they expect to adjust the amounts reported "significantly" once they have completed their investigation of the release.
While both the EPA and TCEQ turned off their air monitors in advance of the hurricane, the EPA was back in Houston neighborhoods once the storm had passed with its Trace Atmospheric Gas Analyzer, a lab bus that takes samples and measures air quality directly. Using the TAGA bus, EPA officials concluded that the probable source of benzene and volatile organic compound readings in and around Manchester was the roof failure and spill from a light crude storage tank at the Valero Houston Refinery during Harvey, according to a release.
Until the EPA finishes investigating, the jury is out on how much Valero ultimately released, but based on the amount of benzene traced in the air after the hurricane, we're betting it won't be a small amount.
Meanwhile, Valero has been back up and running since shortly after the storm.