SAN JUAN, Puerto Rico — The Environmental Protection Agency on Monday ordered the owners of an oil refinery in the U.S. Virgin Islands to remove thousands of pounds of chemicals from the site, warning that its pipes and valves are severely corroded and in disrepair.

The EPA estimates that more than 40,000 pounds of anhydrous ammonia and more than 37,000 pounds of liquefied petroleum gas are stored at the refinery in St. Croix. It also ordered the removal of hydrogen sulfide.

The order comes after the EPA inspected the refinery in September and found serious deficiencies that could lead to a fire or chemical release, including piping and valves on LPG units that are severely corroded and in disrepair. Last month, the EPA announced the oil refinery could not resume operations without obtaining a clean air permit.

The refinery was forced to pause operations in May 2021 following an EPA emergency order, with the agency noting that the facility is located near marginalized communities where people have been sickened and schools forced to close.

The refinery, once the largest in the Western Hemisphere, was built in the mid-1960s and became the largest private employer in the U.S. Virgin Islands at the time. It was originally owned by Hovensa, a joint venture of U.S.-based Hess Corp. and Venezuela’s state-owned oil company, which shuttered the facility in 2012 following multimillion-dollar losses.

It then served as an oil storage terminal until Limetree Bay Energy restarted the refinery in February 2021 after buying it in 2016. However, the EPA suspended its petroleum refining and processing operations last year following a series of environmental violations.

The refinery is currently owned by Port Hamilton Refining and Transportation LLLP and West Indies Petroleum Limited, which did not return a message seeking comment.