Dublin City Council's sewage plant at Ringsend is treating nearly 20% more effluent than it is supposed to.
The data is contained in a Council submission to An Bord Pleanála that states the current volume of material significantly exceeds design capacity.
Yesterday, Environment Minister John Gormley announced he was starting an investigation into the design and operation of the Dublin sewage plant.
The move coincided with revelations that the Council was going to pay the consortium operating the plant an additional €35.6m.
It appears now that the payment is related to the fact that the plant is operating far and above the levels that it is supposed to.
The information is contained in a submission to An Bord Pleanála from last November, regarding the proposed expansion of the plant by roughly one-third.
The Council states that the throughput of the plant was estimated to be at 1.9m PE, what is termed population equivalent.
However, the full capacity of the plant is only 1.6m PE.
This means the Ringsend facility is dealing with 18.75% more waste that it should be.
The Council has said it will co-operate fully with the Minister's investigation, restating remedial work on the plant will be completed on time and on budget.
