Approximately €50 million will be invested to upgrade sewer network

Irish Water is submitting a compulsory purchase order to An Bord Pleanála to acquire the necessary lands to upgrade the existing sewer network serving Blanchardstown and surrounding catchment areas. These include Mulhuddart and Castleknock in Dublin, Dunboyne, Clonee, Ashbourne and Ratoath in County Meath and in Kildare. The proposed project will be located along the Tolka River Valley in Blanchardstown between Parslickstown and Mill Road. A new pumping station will be constructed at Waterville close to Mill Road.

The project represents an investment of approximately €50 million by Irish Water. The investment will expand the existing capacity of the wastewater network in the area to facilitate existing and future residential and commercial growth. The project will also benefit the environment as the increased sewer capacity will reduce the frequency and volume of overflows of untreated wastewater from the network into the River Tolka. It will also support the future economic and social development in Blanchardstown and surrounding areas in Meath and Kildare.

Construction of approximately 3.2kms of new sewer pipelines using trenchless tunnelling techniques

The proposed project will include the construction of approximately 3.2kms of new sewer pipelines. Trenchless tunnelling techniques will be used alongside the existing sewer network between Parslickstown and Mill Road in Blanchardstown. The construction of underground flow balancing storage tanks with a total combined capacity of approximately 30,000m³. A new below-ground pumping station with above-ground control room will be constructed. This will be situated on the site of the existing Tolka Valley Park Pumping Station at Waterville near the Mill Road. A new control building to house all electrical switchgear, control equipment, an odour control unit, a generator room and ESB sub-station.

During the project local sewer and utility diversions will be carried out to facilitate construction of the flow balancing storage tanks and Tolka Valley Park Pumping Station.  Once the proposed project is complete the area will be fully reinstated to match the original condition and associated site works.

Existing network does not have capacity to serve growing population

The existing sewer network (9C sewer) was originally constructed in the Tolka Valley in the 1970s to serve Blanchardstown, Mulhuddart and Castleknock. Since its construction, the catchment area has undergone significant growth. As a result the sewer now serves Blanchardstown and a number of additional towns in County Meath including Dunboyne, Clonee, Ashbourne and Ratoath. The existing sewer network does not have the capacity to serve the needs of this fast growing population. It is also subject to flows which results in untreated wastewater overflows from the sewer network to the River Tolka.

Irish Water carried out site investigation works in Autumn 2016 on the proposed route. This informed the design, construction methods and contributed to the Environmental Impact Statement. Following the submission of a planning application in May 2017, the scheme was granted planning permission in July 2017 subject to 14 planning conditions.

John Joyce, Wastewater Infrastructure Programme Regional Lead at Irish Water, said “Irish Water is pleased to be progressing this important project for Blanchardstown and the surrounding areas in Dublin, Meath and Kildare. The proposed project will expand the existing capacity of the sewer network in the area to facilitate existing and future residential and commercial growth. Irish Water is committed to investing in the sewer treatment infrastructure in Blanchardstown to support the needs of this fast growing population.  The investment will benefit the environment as once completed there will be fewer overflows of untreated water to the River Tolka.”

For more information, please visit our page on the Blanchardstown Regional Drainage Scheme. If you have further queries or comments about this project, you can email our Project Team  at  

Poor condition of Ireland’s water infrastructure

Irish Water spent over €530 million on water services in 2016. Capital investment in the region of €700 million per year is needed for a sustained period of several decades. This is to address the poor condition of Ireland’s water infrastructure. Works have been prioritised to address the most critical issues in line with commitments outlined in Irish Water’s Business Plan up to 2021. Delivery of the business plan will involve a €5.5 billion investment in capital spending on drinking water and wastewater quality and capacity. It also includes new infrastructure up to 2021 while achieving efficiencies of €1.6 billion.

Dublin, Kildare, Meath

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