The completion of a drainage tunnel will have a major impact on the water quality in Dublin Bay.

In a few days time the final connections on the Dublin Drainage Tunnel, a three mile long tunnel along the side of the Grand Canal, will be made 25 feet  below Leeson Street Bridge.

The tunnel has taken two and a half years to construct at a cost of £4 million. It is a key link in a £13 million drainage scheme due for completion in 1979.

When the scheme is completed it will have a major impact on the water quality of Dublin Bay. In a recent EEC report on the Bay, the Bull Wall and Killiney Bay in Dublin fell short of EEC bathing standards. However the report notes the work being undertaken will eliminate pollution from both areas.

Dublin Corporation says most pollution is caused by effluent discharged into the River Liffey which then enters Dublin Bay. When the drainage scheme is finished, the effluent will travel along the three mile tunnel to the treatment plant in Ringsend.

Kevin Byrne from Dublin Corporation says the tunnel will improve water quality in the River Liffey which is badly polluted by effluent in the River Camac, a tributary river. These effluents, mostly from paper mills and other industries, will flow into the new tunnel and onto the treatment works at Pigeon House. 

This polluting material will be excluded from the Liffey, which will greatly improve the water quality in the Liffey itself.

At the mouth of the Liffey is the old sewer discharge from the Pembroke sewer. This discharge will be taken into the new treatment works and treated and the waste will be barged out to sea. 

This will greatly improve the water quality down there at the mouth of the river as well.

An RTÉ News report broadcast on 4 July 1975. The reporter is Conor McAnally.