The Poolbeg incinerator could burn 90,000 tonnes more rubbish.
Its operators have applied for permission to increase the amount of waste consumed by the plant to 690,000 tonnes -- a 15 per cent increase.
85 per cent of the waste currently burned there comes from the capital and eight counties in Leinster, and the rest from within Ireland, according to the Sunday Business Post.
Ian Lumley from environmental group An Taisce says the incinerator is locking Irish people into bad waste habits.
"It's always an issue with these types of projects -- get your foot in the door and then lock everybody into dependency and increase the capacity over a period time," he said.
"This is clearly going to reopen the whole question of what's going into it, what sort of lifestyle are we creating that we can't come up with anything better than to burn stuff.
Meanwhile a new poll has found there's broad support for a ban on single-use plastics.
The Sunday Independent reports 74 per cent of people say they should be banned -- and the same share of people say they've taken steps to change how they use disposable plastics.