There are plans for the Poolbeg incinerator in Dublin to burn 90,000 tonnes more refuse.
Its operators have applied for permission to increase the amount of rubbish processed at the plant by 15% to 690,000 tonnes.
85% of the waste it burns comes from the capital and eight Leinster counties with the rest coming from others around the country.
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," said Mr Lumley.
"Get your foot in the door and then lock everybody into dependency and increase the capacity over a period of time.
"That has happened with the County Meath incinerator also.
"This is going to re-open the whole question of what's going into it?
"What sort of lifestyle are we all creating that we can't come up with something better than to burn stuff?"