Welcome to the final Greater Dublin Drainage update of 2015.

In this update, we look at why a new regional wastewater treatment plant is needed to serve Fingal and the Greater Dublin Area. We delve into the Environmental Impact Assessment process being undertaken as part of the preparation of a planning application for the GDD project. Finally, we take a pictorial look back at 2015!

 Meeting our Future Wastewater Treatment Requirements

Wastewater is created in our everyday lives. At home, we turn on the tap, flush the toilet, hit the button on the washing machine or twist the nozzle on the shower.  At work in our factories, hospitals, schools and offices, wastewater is also created each day.

Untreated wastewater poses a threat to public health and to the environment. That is why wastewater needs to be treated to appropriate standards to produce an environmentally safe liquid that can be returned to our rivers and seas.

The Greater Dublin Area (GDA) is the area with the highest wastewater treatment requirement in Ireland. It comprises the four Dublin Local Authorities[1] and the surrounding counties of Kildare, Meath and Wicklow. The Central Statistics Office Regional Population Projections for the Greater Dublin Area predict that its population could increase by as much as 1% per year (and by over 400,000 people) to 2,197,000 by 2031.[2]

Today, development is constrained in some parts of the Greater Dublin Area. The reason for this is partly due to a lack of essential infrastructure in some areas. Wastewater treatment facilities form part of the primary infrastructure network that is necessary to allow essential development, including housing to occur.

Currently, the GDA is serviced by eight main wastewater treatment plants[3] (the largest being Ringsend WwTP) and by more than 50 smaller local facilities. It was a recommendation of the Greater Dublin Strategic Drainage Study (2005)[4] and the associated Strategic Environment Assessment (2008) that the main treatment plants be upgraded to their ultimate capacities and these works are either complete or in progress.

However, even with these upgrades, in order to meet projected demand in this area, by the mid-2020s there will be a need for a new regional wastewater treatment facility to serve Fingal and the Greater Dublin Area.

The preferred project solution for Greater Dublin Drainage was identified in 2013 following a comprehensive site selection process. It involves developing a new wastewater treatment plant at Clonshagh (Clonshaugh); an underground orbital sewer and two pumping stations; and an outfall pipeline discharging to the Irish Sea (1km north-east of Ireland’s Eye).

Greater Dublin Drainage Preferred Site and Route Option

Greater Dublin Drainage Preferred Site and Route Option

At operation, over 50% of the load to the new regional wastewater plant at Clonshagh (Clonshaugh) will come from Fingal including from part of the North Fringe area (Dublin Airport, Meakstown, Grange/Baldoyle) as well as from the Blanchardstown catchment. The remainder will come from the northern fringes of Dublin City and south east Meath – intercepting sewers that currently go to Ringsend. The new GDD facility will form a key part of the regional drainage network and will enable residential and commercial development to occur both in Fingal and in the wider region.

“Fingal has a proud tradition of supporting economic development. We have some very significant economic clusters in the county, notably in the pharmaceutical, ICT and aviation sectors and these employ thousands of people and support many other jobs,” says Paul Reid, Chief Executive of Fingal County Council. “There is great potential for further economic development in the county. This potential is in part a result of the benefits from strategic assets in the Greater Dublin Area and we are proud to be part of a strong region.”

“Like other areas within the GDA, we are also experiencing housing issues –both in social and private housing. Fingal has the land to help to address this issue. However, we must have the right infrastructure in place to enable development. This includes transport, energy, water and wastewater infrastructure. That is why Greater Dublin Drainage is a vital project for Fingal.”

Jerry Grant is Head of Asset Management at Irish Water. “The GDD project is a key element of the Water Services Strategic Plan which sets out the strategic objectives for the delivery of water services in Ireland over the next 25 years, up to 2040. This modern facility will ensure that wastewater generated from the continued growth and economic development in the Dublin region is appropriately treated in order to safeguard human health and to protect the environment – in compliance with the relevant EU Directives and national regulations on water quality.”

Irish Water is currently progressing all of the licence applications and environmental studies required to prepare a planning application for the GDD project which it intends to lodge with An Bord Pleanála before the end of 2016.[5]

Protecting the Environment

GDD is being developed primarily to safeguard public health and to protect and improve the environment.

An Environmental Impact Statement (EIS) will be submitted to the Planning Authority along with the planning application. The EIS is a report that contains detailed analysis of the potential impacts of a proposed project on the existing environment and includes sufficient information to allow the consenting authority (in the case of GDD, An Bord Pleanála) make a decision on whether consent should be given to the project.

The key elements that are considered as part of an EIS include an assessment of the following topics:

EIS Categories

EIS Categories

Environmental Studies
In 2015, the GDD project team has been undertaking many studies to inform the Environmental Impact Statement (EIS). Surveys include terrestrial surveys, bird surveys, freshwater surveys, marine surveys, marine ground investigations and marine geophysical surveys.

The Irish Whale and Dolphin Group[6] has been carrying out a survey for the Greater Dublin Drainage project since February 2015 to establish the extent and nature of marine mammal life in the area off the north Dublin coastline near Ireland’s Eye. The study aims to assess the distribution, habitat use, seasonal occurrence and behaviour of marine mammals in the study area. Three types of surveys are being conducted as part of this study; land-based, boat-based and acoustic techniques. Data gathered during this survey, along with the findings of the other marine studies being conducted, will be used to inform the decision on the most appropriate construction methodology for the marine outfall pipe.

Conducting these necessary environmental surveys will help to ensure that the GDD project is developed in a way that safeguards the quality of the marine environment, our beaches and our bathing waters.


The Year in Photos – 2015

2015 has been a busy year for the GDD project. In addition to the surveys outlined above, the project team continued to communicate with stakeholders at information events and project briefings, through regular email updates, via the project information line, email and website, and in the media. Here is a selection of photos from the year gone by…



February – Marine mammal survey by the Irish Whale and Dolphin Association gets underway off north Dublin coast

   PublicInfoEvents1   PublicInforEvents2

July – Public information events at Howth, Baldoyle and Portmarnock


August – October – Marine ground investigations off the north Dublin coast near Ireland’s Eye and at Velvet Strand, Portmarnock

Contact GDD

Please feel free to contact the project team with any feedback or questions using the contact information below.

We wish you a happy and safe holiday season and we look forward to keeping you up-to-date with the GDD project in 2016.

References & Links
[1] Fingal County Council, Dublin City Council, South Dublin County Council and Dun Laoghaire Rathdown County Council.
[2] http://www.cso.ie/en/releasesandpublications/er/rpp/regionalpopulationprojections2016-2031/
[3] GDA main WwTPs are: Portrane, Malahide, Ringsend, Swords, Lexlip, Shanganagh, Barnageeragh and Osberstown.
[4] http://www.greaterdublindrainage.com/gdsds/
[5] http://www.greaterdublindrainage.com/the-project/project-roadmap/
[6] http://www.iwdg.ie/