Arklow Wastewater Treatment Plant

Arklow has been identified by the Environmental Protection Agency (EPA), as an area where wastewater is discharged into the Avoca River without any treatment. This practice of discharging untreated wastewater to the river is no longer acceptable and Uisce Éireann intends to fix this problem in partnership with Wicklow County Council.

The provision of a new wastewater treatment plant in Arklow will bring benefits to the town and surrounding areas in terms of health, environmental protection and improved water quality for all.

Arklow, Wicklow
In Progress

Project Objectives

Arklow Wastewater Treatment Plant must be delivered in a way that not only meets the required legislative standards but that also ensures that all works are undertaken in a safe and environmentally responsible manner, in cooperation with the local community.

The objectives of the Arklow Wastewater Treatment Plant project are as follows:

  • To stop the current practice of discharging untreated wastewater to the Avoca River
  • To provide a wastewater treatment facility that will comply with all relevant legislative requirements and will service the population of Arklow into the future
  • To improve water quality in the Avoca River

What is involved?

The Arklow Wastewater Treatment Plant project includes:

  • A new, state of the art, wastewater treatment plant that has been designed to provide an ultimate treatment capacity for a PE (population equivalent) of up to 36,000 at the Old Wallboard Factory, North Quay, Ferrybank
  • Sewer pipelines (along the North and South Quays) to bring the untreated wastewater to the WwTP
  • A marine outfall pipe to safely discharge the treated wastewater to the Irish Sea

Stakeholder Engagement

Who can I contact if I want to find out more about this project?

Members of the public are welcome to contact the Project Team if they have any questions on the Arklow Wastewater Treatment Plant Project and can do so in the following ways:



A dedicated Community Liaison Officer has been appointed for the duration of this project. If you require further information regarding the works, please contact the project team or Ward and Burke Water Ltd on 086 1036300.

Progress Update:

Underground tunnelling

Tunnelling commenced in March 2022 from the Ferrybank Roundabout using a specialised tunnel boring machine. The first drive is now complete, with approximately 480m of new sewer now constructed between the Ferrybank Roundabout, along the front of the Bridgewater Shopping Centre and the Marina Village Apartments. This method of tunnelling is very complex; however, it was necessary to carry out the tunnelling in this way (rather than open cut trenches) to minimise disruption as much as possible for residents, businesses, and customers in the area.

Tunnelling continued through August 2022, including under the River Avoca, where a new sewer is being installed under the river, connecting the North and South Quay wastewater infrastructure. At the end of August 2022, Drive 2 and Drive 3 are 95% complete, with an expected date of January 2023 for the connection to be fully completed. Check out some images of the Tunnel Boring Machine as it was launched into the newly constructed shaft at the Ferrybank Roundabout:

Figure 1: The tunnel boring machine being launched into the underground shaft.

Figure 2: : The tunnel boring machine which is facilitating the installation of the new sewer pipelines.

Figure 3: The tunnel boring machine being launched into the underground shaft.

Long Sea Outfall:

The long sea outfall pipe will safely discharge the treated wastewater to the Irish Sea when the new wastewater treatment plant is operational. This new pipe was brought by boat from Norway in recent weeks and was installed along the seabed over Summer 2022 using specialised equipment and marine vessels.

The long sea outfall pipe comprises of a HDPE pipe with an internal diameter of approximately 630 mm. Six vertical diffusers will emit the effluent approximately 900 metres out to sea at a depth of approximately 10 metres below sea level. Flow through the long sea outfall pipe will be via gravity.

Check out some images of the arrival of the outfall pipe from Norway along with the specialise dredger which will help install the outfall pipe at sea:

Figure 4: The long sea outfall arriving in Arklow from Norway.

Figure 5: Long Sea Outfall Razende Bol – Backhoe Dredge which will install the long sea outfall.

Figure 6: Works at the inlet pumping station are progressing well.

Figure 7: Works at the wastewater treatment plant site are progressing well