The cause of a foul odor that lingered for several days in St. Rose, LA, ended up linked to the refining of a crude oil that contained high levels of sulfur compounds, a state Department of Environmental Quality (DEQ) spokesman said.
Officials will remove the asphalt product made from the crude oil and International-Matex Tank Terminals and Shell Chemical have taken responsibility for producing the odor, DEQ spokesman Greg Langley said.
IMTT and Shell jointly operate the asphalt production plant, in St. Charles Parish off River Road in St. Rose.
“They had a certain kind of crude that they were using that they hadn’t used before. When they refined it, it produced some sulfur compounds,” Langley said. “Sulfur compounds can generate odors. This particular crude had these compounds in its feedstock, and it caused the odors to come out.”
Langley said the crude used had a higher level of sulfur than the refinery was set up to process and the plant’s equipment used to help control odors didn’t work properly which contributed to the problem. The company cleaned the equipment and it will add a caustic scrubber to help remove potential pollutants, he said.
Residents complained since June 7 the odor has caused them ailments, such as nausea, vomiting, headaches and other respiratory and digestive illnesses.
However, Langley emphasized the department’s “extensive” and “real-time” air sampling from the site and in the community met EPA air quality standards.
“We have found no levels that are harmful to human health,” he said.
Langley said the company has removed that particular feedstock from their list of approved crudes to refine.
Langley said the DEQ will continue to monitor the situation and that the companies have agreed to upgrade their odor protection and reporting system. The companies also are looking at creating a helpline for residents to call to report incidents and get information, he said.