Delaware natural resources officials say the pollution release will begin early Friday and continue into the weekend. The refinery often sends up clouds of gasses during shutdowns and startups of its major systems.
The burning of waste gases can still generate tons of sulfur dioxide gas as a byproduct.
Valero announced last week that it would close the plant, citing losses of $1 million a day since January. About 500 full-time employees and hundreds of contractors will lose their jobs.
Information from: The (Wilmington, Del.) News Journal