Orica will continue the start up of its nitric acid and ammonium nitrate plants on Kooragang Island following a review of its operation procedures.
It yesterday stated that Wednesday’s ammonium nitrate overflow was caused by a failed computer card, the Newcastle Herald reported.
Around 20 000 litres of 30% ammonium nitrate solution spilled over a bund around a tank and soaked into the ground; according to an Orica spokesperson the solution was comparable to garden fertiliser, and there was no risk to the public.
The Kooragang Island site manger Sean Winstone told the Herald that the incident occurred "primarily as a result of a failed computer card in the computer control system".
Winstone went on to say that Orica had already reported the incident to the EPA, and believes that it is still safe to restart its ammonium nitrate and nitric acid plants.
However, its ammonia plant remains closed.
According to Australian Workers Union official and local resident John Boyd: "the expert opinion is that Orica is safe".
"[Local residents] can trust the independent toxicologist, the EPA, the department of health, WorkCover and the independent specialist engineers, or can they trust the Stockton Community Action Group and the Greens," Boyd stated.
The EPA lifted the operational prevention notice on the ammonia storage system at Orica’s Kooragang Island plant earlier this week.
It came after a meeting of the Orica Start Up Committee on Monday, which endorsed the removing of the prevention notice on the ammonia feed tanks.
This lifting will allow for the start up of the ammonium nitrate plant, Orica says.
It "has demonstrated to the EPA and other regulatory bodies that it has satisfactorily addressed the issues that caused the 9 November ammonia vapor incident that resulted in the ammonium nitrate plant at the site being shut down," the company said in a statement.
Orica is continuing with the pre start-up testing of the ammonia plant that it began over the weekend.