Council officials say the waste -- mainly crushed rock -- will be generated during the building of a 9km pipe on the floor of the bay.
According to documents filed with the Environmental Protection Agency, the council intends to dispose of this waste just 3km off Howth Head.
However, opposition is already mounting, with local representatives and diving groups angry at the plan.
Peadar Farrell, a diving instructor for Curragh Sub Aqua Club, said the news was "disturbing".
The pipe is being built as part of €200m plans to upgrade the Ringsend Waste Treatment Plant. The council says the plant is running at an "overcapacity"and the new pipe is needed to deal with the sewage waste generated by the 2.1 million residents in the catchment area.
But as result of the construction, up to 824,000 tonnes of 'spoil' -- mainly crushed rock -- will be generated. The remainder will be clay, gravel and sand.
The council recently lodged the application to dump the 824,000 tonnes in a designated disposal site three km off shore.
The waste will be deposited at a rate of one to two loads per day over a three-year period beginning in 2014.
A council spokesman said the disposal site has been used "for many years and is not an area used by recreational divers".
He added: "A Screening for Appropriate Assessment was undertaken as part of this application. It considered impacts on flora and fauna and concluded that there would be no impacts on marine life."
Independent councillor Mannix Flynn described the plans as an "insult" to the local area.
"When the city council becomes a vandal and is engaged in the wholesale dumping of waste in a beautiful and world renowned bay, it's a time to wake up," he told the Herald.
And Peadar Farrell said that the amount of waste will, in his view, have a serious effect on visibility for divers.
A spokeswoman for the EPA confirmed that the application had been received but said that no observations have yet been made.