Chemical spill cause probed
A metal object may have pierced the side of a tank and caused the massive chemical spill at a South West refinery last month, a preliminary investigation has revealed.
About seven million litres of processing “slurry” gushed from a tank at Alcoa’s Wagerup refinery on March 9, with the highly corrosive liquid splashing through the secondary and tertiary containment tanks and onto the bitumen ground below.
There were no injuries caused by the incident and the affected area was immediately shut down.
The State’s peak safety watchdog, the Department of Mines, Industry Regulation and Safety, will this month hand down findings from its investigation into the spill, but an Alcoa spokesperson has revealed a “rake arm inside the vessel punctured the side of the tank”.
Information obtained from the department indicates an inquiry into the spill is ongoing, with investigators searching not only for the cause of the spill, but for ways to ensure this kind of incident does not occur in the future.
The department and Alcoa, along with the Department of Water Environment Regulation, are working on the investigation. An Alcoa spokesman said while the company worked actively to avoid incidents of this nature, spills could occur.
“All of Alcoa’s refineries, including Wagerup, have been designed to ensure that if spills do occur, they can be safely contained within the refinery footprint and not flow to the surrounding environment,” he said.
The spokesman said containment “bunds” at all sites capture any spilled material.
“Any materials that enter a refinery’s closed drainage system report to facilities at the residue storage area,” he said. “The incident was contained to the operating footprint of the refinery, with the majority of the material captured by the bund directly underneath the tank and on adjacent bitumen.”
The spokesman said Alcoa staff acted immediately to begin the clean-up at the site, closely following the company’s safe-operating procedures.
“The clean-up process involved recovering the material using a variety of methods including vacuum pumps. This material was either returned to the process or taken to the residue storage area.
The spokesman said the investigation would help to improve safety at this and other sites.
“Opportunities to improve operating procedures will be identified and implemented where practicable,” he said.
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