The two proposed sites for a new incinerator have attracted opposition from local groups concerned about the impact on the environment.
Cardiff Against the Incinerator and Stop Newport Incinerator say that a better solution to domestic waste would be to increase recycling targets.
The two bidders, Veolia and Viridor, say that the plans represent a major investment and electricity generated by the incinerator will help power local homes and businesses.
More top news
Well a fabulous day today has ended on a spectacularly soggy note for some! Heavy rain, hail and thunder will work northwards overnight!
The Talyllyn runs from Tywyn, near Aberdovey, for more than seven miles to two villages in the south Gwynedd countryside.
Homes in parts of Tonypandy and Llwynypia are without water this evening due to a burst water main at Cilfynydd.