The economic viability of the incinerator proposed for Dublin's Poolbeg peninsula is being undermined by an excess of landfill capacity, waste management companies have claimed.
The excess capacity - which effectively makes it cheaper to dump rather than to recycle or recover energy from waste - was revealed in a study of the amount of licensed landfill space in the Republic.
The study, Excess Landfill Capacity - and its impact on implementation of Irish Waste Policy, claimed the Republic dumped just 1.9m tonnes of waste in landfill in 2005. However it points out that An Bord Pleanála has granted permission for almost four million tonnes of annual capacity.
In addition, the Environmental Protection Agency has approved almost five million tonnes of annual capacity, a feature which the report's authors insist has the potential to dramatically reduce the cost of dumping.
The study was carried out by the Confederation of European Waste to Energy Plants, whose vice-president is John Ahern of Indaver Ireland. Its contents have been supported by Repak, the industry-funded recycling initiative, and major operators such as National Toll Roads plc.
According to Indaver, landfill capacity should be reducing in line with national and regional waste strategies, making dumping the most expensive of our waste-management options.
"Ireland will be unable to break its age-old link with landfill if excess capacity is allowed to continue," Mr Ahern warned. "It seems there is confusion as to who is responsible for monitoring landfill capacity - neither the EPA nor An Bord Pleanála appear to be monitoring capacity on a national level."
John Mullins, chief executive of Bioverda, a bio-energy subsidiary of utilities group NTR, said gate prices at landfill had fallen dramatically in recent times due to over-capacity.
Mr Mullins said gate prices must remain at about €100 a tonne to make alternatives such as recycling or energy recovery economically viable. There was a real danger that the economics of incinerators, including that proposed for Dublin, would not be viable.
According to Darley Crowe of Repak, falling landfill gate prices also threatened the viability of recycling schemes.
In the recent past landfill was about €130 a tonne, up from about €22 (£15) a tonne in 1999, "making it viable for operators to recycle", but he warned that when landfill charges dropped below about €80 a tonne, it would be cheaper to dump rather than recycle.