Dublin City Manager Owen Keegan has said the Poolbeg project has proved extremely challenging and it has gone on for far too long.
He has been giving his opening statement to the Oireachtas Environment Committee in relation to the proposed 600,000 tonne Poolbeg incinerator.
In excess of €96m has been spent by the council over more than ten years on the incinerator, which remains unbuilt.
The committee meeting was delayed by almost two hours this afternoon due to private session.
Mr Keegan said the Dublin Waste to Energy project was subject to unanticipated delays due to a range of factors largely outside the control of the Dublin local authorities.
These delays, he said, had contributed to significant costs, incurred to date by the Dublin local authorities and the PPP Company, in seeking to advance the project.
He said a total of €96.3m had been spent on the project by the Dublin local authorities to 31 December 2013.
Of this total he said €4.5m was recouped from the PPP Company, in accordance with the Project Agreement, and grant aid of €7.5m was received.
Mr Keegan said if the project did not proceed - the bulk of the costs incurred by the Dublin local authorities would not be recouped.
However, he said if it did proceed there would be a real prospect that the Dublin local authorities would recoup the full investment they had made in the project to date.
Mr Keegan said he was eager for the project to go ahead.
But when asked if it will proceed he said: "I don't know".
Dublin City Council has confirmed it spent €29.77m on consultants working on the Poolbeg Incinerator project, which initially projected it to be €8.3m.
Mr Keegan said the "fundamental problem" regarding the original scope of the Poolbeg contract was that it was "inadequate in relation to the work and duration of the assignment".
He criticised Dublin City Council over its failure to break the contract in 2005 when it exceeded the 50% public procurement guideline threshold.
However, he pointed out that no one foresaw the project going "on as long" as it did.
He said part of what has "bedevilled the project is time scales".
Labour TD Kevin Humphreys has asked members of Dublin City Council who were before the Oireachtas Environment Committee today if the total cost of the proposed Poolbeg Project of €96m included the District Heating Project.
Mr Keenan said the District Heating Project, which cost €10m, had always been viewed as a "separate project" by the City Council as it was not dependent on the incinerator going ahead.
Mr Humphreys put it to the City Council representatives that the overall spend for Dublin County was €96m and the district heating project was a €10m "add on" Dublin City Council.
Mr Humphreys said in his view that it was "all part of the same expenditure".
The Dublin City Council Manager said €12m had been funded by the Department and the PPP Company.