Dublin City Council is to apply to An Bord Pleanála for permission to extend the Ringsend Wastewater Treatment Works (WWTW). The WWTW was identified in the Greater Dublin Strategic Drainage Study as being essential for the development of a sustainable drainage system for the Greater Dublin Region. This is a Regional facility that treats wastewater from the Dublin City Council area, together with parts of Fingal, South Dublin, Dun Laoghaire-Rathdown and Meath County Council Areas.
The WWTW is being extended to cater for future demand while maintaining its high level of treatment and removing the treated water discharge from the environmentally sensitive Liffey River Estuary using a new long sea outfall tunnel under the seabed to a point approximately 9 kilometres further offshore. The new location will take advantage of improved dilution and dispersion due to greater water depths and stronger tidal currents. It will move the treated water further from bathing waters and wildlife sanctuaries. This will further improve the value of the bay and the estuary as cherished public amenities.
According to Pat Cronin, executive manager of Dublin City Council: “Long Sea Outfalls have been employed at some of the largest coastal cities in the world. Many, including Barcelona, Miami Beach, Sydney, Boston and Lisbon are known for their vibrant harbours and recreational opportunities. Dublin City Council is proposing this extension to meet current and future requirements to treat our wastewater. These proposals would allow the Ringsend Plant to treat wastewater for a population equivalent of 2.1 million which is just 30% above current capacity.”
Currently, the plant discharges treated effluent into the Lower Liffey Estuary on the Poolbeg Peninsula. This area has been designated as a sensitive water body under the EU Urban Waste Water Treatment Regulations as it is vulnerable to enrichment by nutrients (Nitrogen and Phosphorous). The proposals include a plan to comply with the Regulations by discharging effluent via the new tunnel.