It's thought a discharge of algae inside a pipe at Kooragang Island is what landed Orica Australia a $15,000 fine from the NSW Environment Protection Authority (EPA).
The incident was reported to the EPA on 9th March this year, just one day after it occurred.
The EPA said it's likely sediments were also dislodged resulting in concentrations of suspended solids, zinc and arsenic in the effluent becoming higher than the levels permitted by Orica's environment protection license.
It's not the first time Orica has been fined by the EPA, there was another incident in October 2013 where they were fined $1,500 for exceeding their effluent concentration limits - also attributed to algae build-up.
They were also most recently cautioned in December 2016.
