Nov. 17, 2001 — Emergency response crews have been working around the clock since Wednesday, when a 97,000-gallon tank of sulfuric acid began leaking at St. Croix Alumina.
Officials from the Department of Planning and Natural Resources, U.S. Environmental Protection Agency, the Aluminum Company of America, which owns St. Croix Alumina, and workers from the adjacent Hovensa oil refinery are trying to empty the leaking tank to prevent a catastrophic failure. While no injuries have been reported, efforts to remove the dangerous acid have run into troubles.
First attempts to transfer the acid to a lined berm were called off when the acid-resistant liner ruptured, causing an additional release of at least 3,000 gallons, according to Dean Plaskett, DPNR commissioner. The acid soaked into the soil below the liner and then seeped onto an adjacent road and into the a nearby ship channel.
When the acid mixed with the water, a vapor cloud formed but was localized and dissipated rapidly, Plaskett said.
Jim Casey, the EPA's V.I. coordinator, said officials are still investigating the incident to determine if negligence was involved. Alcoa closed the plant earlier this year and only about a dozen people work there now. The nearest communities are Estate Profit and Harvey Project.
"there isn't any danger to residents in the adjacent communities, which is quite aways away," Casey said.
Crews are now in the process of fabricating a piping and pump apparatus to transfer the acid, of which about two-thirds remains, to another tank on the Alumina property. Once transferred, the acid will be neutralized so it can be safely loaded into tanker trucks. The trucks, which Plaskett said must be shipped from Puerto Rico, will take the acid to Hovensa for further treatment.
Meantime, a tertiary containment berm is being constructed around the leaking tank to minimize the impact if the acid tank fails, Plaskett said.
The area where the acid has leaked into the ship channel is being monitored, but environmental impacts have so far been minimal.
"DPNR has observed … the burning of upland vegetation by he acid vapor cloud, bleaching of benthic marine algae and at least four dead fish," Plaskett said. "The sulfuric acid is denser than sea water and slowly sinks to the bottom."
Plaskett said the acid will gradually dilute and buffered by the sea water until the acidity is reduced to that of the surrounding water.
"No coral reefs are located in the immediate vicinity of the discharge," he said. "Only one white mangrove has been impacted by the event."
As a precautionary measure, DPNR closed the St. Croix Alumina complex to the public, including the sports field, running track and the northern portion of the St. Croix Alumina ship channel.
