Dublin Bay is a complex eco-system. The EPA has classified the water quality in Dublin Bay as ‘good’ under the water framework directive for the period 2013 to 2018, an improvement on the ‘moderate’ status achieved during the 2007 to 2009 period.
Significant investment in waste water infrastructure continues and is provided for in the Irish Water Strategic Funding Plan. It is estimated that €1.9bn will be invested in waste water projects between 2019 to 2024. It is well known that our waste water networks require ongoing and sustained investment to bring these up to the required standard of treatment; to deal with population growth; and to adapt to the impacts of climate change. Ringsend wastewater treatment plant was originally designed and built to treat wastewater for a population equivalent of 1.64 million and is now overloaded. In response, Irish Water is currently undertaking a major upgrade of the plant to ensure that the wastewater is treated to the required standard, to reduce nutrient discharges, and to improve the water quality in the Lower Liffey Estuary. Irish Water is installing a novel Aerobic Granular Sludge (AGS) technology which is an advanced nutrient removal process that is designed to consistently produce high-quality treated waste-water which can be safely discharged into Dublin Bay. This upgrade will increase the capacity of the plant to cater for the growing population of the Greater Dublin Area and will address compliance with EU law. Planning permission was granted for the project in April 2019, and will be completed in two phases; bringing the plant up to compliance with EU law in 2022 and a capacity upgrade by 2024.
There are instances of bathing water quality issues in some areas of the Bay. There are multi-faceted sources of pollution that may be impacting on the bathing water quality in Dublin Bay. This includes sewer misconnections to surface water drains and streams, sewer storm water overflows, wildlife and dog-fouling. The Dublin local authorities are working together to diagnose the root-causes and put in place programmes to solve these issues.
It should be noted, that any water that is released from storm-water overflows into Dublin Bay happens after heavy or prolonged spells of rain, and has been heavily diluted with rainwater.
