By Laura Sanicola
(Reuters) -The Limetree Bay refinery in St. Croix is releasing "light hydrocarbon odors" due to maintenance being conducted on its coker unit, prompting nearby schools to dismiss students, the company and the U.S. Virgin Islands Department of Education said on Thursday.
Three St. Croix schools in the U.S. Virgin Islands closed campuses on Thursday due to a noxious odor affecting air quality on campus, the department said.
"We will continue to monitor the situation, but there is the potential for additional odors while maintenance continues," the company said, apologizing for the impact on the local community.
The gassy odor has been present since Wednesday, according to residents on St. Croix. The nearby Limetree Bay refinery, had been the source of noxious odors last month that caused some residents to feel ill and also shut schools.
Limetree Bay had said on Wednesday that its preliminary investigations revealed refinery units are operating normally and there was no activity that would have resulted in an odor.
During the April incidents the U.S. Virgin Islands Department of Planning and Natural Resources (DPNR) determined that the Limetree Bay refinery was emitting excess sulfur dioxide due to hydrogen sulfide being burned.
The company agreed to resume sulfur dioxide monitoring, days after the U.S. Environmental Protection Agency notified the company that it was in violation of the Clean Air Act.
Even short-term exposures to elevated levels of sulfur dioxide can harm the human respiratory system and make breathing difficult, according to the EPA.
The DPNR said its team is currently investigating the situation in the field.
The EPA, which deployed staff to investigate ongoing issues at the refinery in April, said it is taking seriously reports of residents sickened by emissions around the facility.
"If EPA makes a determination that the facility's operations present an imminent risk to people's health, consistent with its legal authorities, it will take appropriate action to safeguard public safety," the agency said in a statement.