The court was told dust from Alcoa’s residue disposal area crossed over the boundary of the site into the environment on May 29, 2011.
This was in contravention of Alcoa’s operating licence and the Environmental Protection Act 1986.
Magistrate Paul Heaney also ordered Alcoa to pay $1849 in costs.
After sentencing, Department of Environment Regulation acting director general Jason Banks said prosecution was only one of the many tools available to the department to achieve compliance.
An Alcoa spokeswoman said the breach was unintentional and involved dust from bauxite residue drying areas crossing the boundary.
‘There was no reported detrimental health or environmental impacts from the incident,’ she said.
‘Alcoa has comprehensive policies and procedures in place to control bauxite residue dust at its Wagerup refinery, including 715 water cannons, an online weather monitoring system to predict adverse weather conditions and a real time alarm system triggered by air monitoring equipment.
The spokeswoman said since the incident, Alcoa had reviewed and where appropriate had further improved its internal dust management policies.