A GIANT 9km pipe aimed at making Dublin Bay cleaner will cost a massive €220m, councillors have been told.
Dublin City Council is proposing to build the 5m-wide pipeline from the Ringsend sewage plant in order to increase its capacity and comply with stringent new water quality standards.
The outfall pipe -- which would be longer than the Dublin Port Tunnel -- will be used to dump effluent from the facility into the sea almost 9km from the shore.
However, the mammoth undertaking will cost nearly three-quarters of the €300m cost of building the entire plant.
The council's head of waste management Pat Cronin said the new pipeline was the "greenest and most economic solution" of the options.
It would increase the capacity of the plant to make it suitable for a population of 2.1 million people -- an increase of 400,000 on current capacity.
If a line was drawn between Howth and Killiney, it would mark the approximate distance of the pipe from the Ringsend facility. "It's a pretty substantial tunnel," Mr Cronin said.
The plans are due to go out to public consultation soon, with a completion date expected to be at the end of 2015.
The current discharge point causes pollution in the inner bay, around Bull Island, and other sensitive areas.
The city council believes the extension would dramatically improve the water quality of the Dollymount beach bathing area, which lost its Blue Flag status for cleanliness this year.
Assistant city manager Seamus Lyons pointed out the bay was not heavily polluted.
"The classification of the inner bay area is being changed under EU designation, which means the relatively minor pollutants that are going into that area at the moment would be above the limit, which means they have to be moved elsewhere," Mr Lyons told a meeting of the local authority's environment committee.
"That's why it's being moved outside a sensitive area," he added.
The scheme is to be funded through the Department of the Environment's water services investment programme.