Greater Dublin Drainage Project – Marine Investigations

Following a statutory public consultation which concluded earlier this year, the Department of the Environment, Community and Local Government (DECLG) has granted a foreshore licence to the Greater Dublin Drainage project to undertake investigative marine surveys in the Irish Sea between Baldoyle and north of Ireland’s Eye. The surveys are being undertaken as part of the preparation of a planning application for the GDD project.

Greater Dublin Drainage is the development of a new regional wastewater treatment facility for the greater Dublin region. The project involves a new wastewater treatment plant located at Clonshaugh; an underground orbital sewer and two pumping stations; and an outfall pipeline discharging treated wastewater 1km north-east of Ireland’s Eye.
A marine ground investigation is being undertaken in order to inform the preparation of the construction method for the marine outfall pipeline. This survey, which will assess the composition of the sea bed,  involves using a jack-up platform (as shown in the attached image) in order to make a number of boreholes along the proposed marine outfall pipeline route.

The platform will be visible from the north Dublin coastline over a four week period from mid-July into August. A notice to mariners will be issued to ensure that other water users are aware of the survey.

One borehole is required to be undertaken on Velvet Strand, Portmarnock. This part of the survey is scheduled to take place in September (weather permitting) in order to minimise any potential impact for beach users. The survey is envisaged to take 2-3 days and Velvet Strand will continue to remain open during the survey.

A number of other surveys are taking place over the next six months including an underwater noise survey, reef habitat mapping, and an archaeological survey. The results of the surveys will feed into the preparation of an Environmental Impact Statement which is being produced as part of the planning application for the GDD project.

Upcoming information events
The GDD project team is inviting members of the public to visit any of the following information events as follows:

–          Wednesday 15th July      Howth Yacht Club                                           10am – 2pm
–          Wednesday 15th July      Portmarnock Hotel & Golf Links               4pm – 8pm
–          Thursday 16th July            Baldoyle Library                                               3.30pm – 7.30pm

GDD spokesperson Peter O’Reilly said, “I encourage anyone with questions about the GDD project to come along to any of the forthcoming information events. The GDD project is a vital part of Irish Water’s investment programme to provide the appropriate wastewater treatment infrastructure needed to meet future demand in the Capital region. 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.”

Members of the GDD project team will be available at the events to provide information about the project.  For further information on the marine surveys and information events visit

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