Waste: Is burning rubbish better than burying it?
Burning rubbish saves it being dumped in a hole in the ground, but the practice divides opinion.
There are five incinerators operating in Wales with six more planned - they burn household waste, with non-recyclable items used to create electricity.
Mike Hedges, the chairman of the assembly's environment committee, has said sending rubbish to landfill is better than burning it in large incinerators.
But the practice has divided opinion.