Queensland Alumina Limited has been fined $125 000 after it pled guilty to a caustic slurry leak last year.
In November last year gaskets at the QAL facility failed, causing caustic waste slurry, more commonly known as 'red mud' to disperse as an aerosol towards the nearby suburb of Sun Valley.
Now the company has been fined and a conviction recorded against it, according to the Gladstone Observer.
During the hearing the court heard two gaskets failed, acting as a contributing factor to the release of steam and slurry into the atmosphere.
This latest fine is on top of the company paying out more then $106 000 in claims.
QAL general manager Mike Dunstan voiced the company's repentance for the incident.
"We regret the damage and the inconvenience caused to our neighbours and we accept the court's decision," he said outside the court.
"It's where we come from so all of our objectives are not to cause any harm to
This is the third time QAL has been fined for an incident such as the one in November.