The Bundaberg Regional Council says it is extremely concerned about its main sewerage line that was compromised by the recent floods in the southern Queensland city.
The line runs across the Burnett River from the Millaquin sugar mill in the east to the treatment plant in the north.
Since the floods, the line has become exposed above the water.
Council CEO Peter Byrne says it is a major issue and crews are working around the clock to test the integrity of the sewerage line.
"It's a big deal - probably cost well over a million dollars if it is compromised, but we have got methods in place at the moment to cope with that," he said.
He says plans are being made to re-route Bundaberg's sewerage system.
© ABC 2013
11:55 EST New South Wales residents living near swollen waterways have been advised to stock up on essentials as forecasters warn flooding could isolate parts of the state later this week.