THE Gladstone Ports Corporation has refused to answer questions about whether its Western Basin bund wall failed to meet its environmental commitments.
The GPC is under fire after a report found poor design of the wall allowed dredge spoil to leak into Gladstone Harbour in September 2011.
It has been claimed an engineers' report provided to the GPC in November 2011 linked the huge leak and a plunge in water quality at the time of the fish disease outbreak.
The Observer has asked GPC if the bund wall met its commitments under the Western Basin Dredging and Disposal Project environmental impact statement.
The GPC did not respond, but a spokeswoman said "an extensive monitoring program was established for the duration of the WBDDP".
"The GPC notified relevant regulatory authorities and the community about the leak (when it occurred), and its contribution to turbidity in the harbour," she said.
A new internal wall and seal was then developed.
Independent engineers delivered a presentation to the Great Barrier Reef Marine Park Authority showing that bund wall leaks over two years were due to inadequate lining, placed outside the wall rather than built into it.
In the environmental impact statement, the risk of turbidity around the bund was flagged as high, but GPC said it had committed to a control strategy.
The Australian on Thursday reported the ports corporation was forced to seek urgent permission to breach its environmental approvals in a race to plug the leaking bund wall before it ran out of space to store potentially toxic acid sulphate soils associated with the dredging.
It said an application for a transitional environment program lodged in June last year confirmed the environmental impact of the original bund wall failure and how an initial response had not fixed the problem, and documents showed the ports corporation was aware of the extent of the environmental threat posed by the bund wall failure.