Uisce Éireann has successfully completed the construction of the €139 million Arklow Wastewater Treatment plant, eliminating the discharge of raw sewage into the Avoca River.
Arklow was identified by the Environmental Protection Agency (EPA), as an area where wastewater was discharged into the Avoca River without treatment.
Ireland was taken to the Court of Justice of the EU for its failure to ensure that urban wastewater in 38 agglomerations across the country is adequately collected and treated to prevent serious risks to human health and the environment.
There were multiple planning delays due to site selection for the plant; however, planning was submitted in September 2018 for the construction of the Arklow WwTp, which started in 2021.
Ward and Burke Construction Ltd. completed the works on behalf of Uisce Éireann, six months ahead of schedule and on budget.
What was involved?
Demolition and site clearance of the Old Wallboard Factory.
Architectural design to produce an art piece along the coast of Arklow.
Construction of a new wastewater treatment plant (WwTP) to treat 24,000 population equivalents (with the option to expand to 36,000 PE) at the Old Wallboard Factory site located at Ferrybank, Arklow. On the site of the WwTP there are:
• An Inlet Works Building including a storm water tank.
• A Sludge Tank Enclosure. An Odour Control Unit (OCU) will be located within the Sludge Tank Enclosure.
• An Administration Building.
• A process building including six secondary treatment tanks.
Upgrade to the Rock Revetment along the coast.
Construction of two interceptor sewer pipelines (along North and South Quay) to bring untreated wastewater to the proposed WwTP. Tunnelling works took place using a specialised Tunnel Boring Machine (TBM) to make way for the new sewer pipelines along the North and South Quays, and under the River Avoca.
Construction of a marine sea outfall pipe to safely discharge the treated wastewater effluent to the Irish Sea. This new pipe was brought by boat from Norway 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.
Storm overflow and storm water storage site at the Alps.
Underpinning of the 19 Arches bridge and Quay Wall works to accommodate installation of new interceptor sewer.
Landscaping and associated ancillary works.
Highlights
The Arklow Wastewater Treatment Plant has been fully operational and treating all incoming flows since Q4 of 2024. It has garnered huge interest at home and abroad due to its visually appealing buildings – designed by Clancy Moore Architects – recently winning the prestigious Downes Medal, The Architectural Association of Ireland’s highest honour. This award is not awarded every year which is a testament to the structure itself.
Tunnelling works took place using a specialised Tunnel Boring Machine (TBM) to make way for the new sewer pipelines along the North and South Quays, and under the River Avoca, to minimise impact on the local community.
Long Sea Outfall:
The long sea outfall pipe safely discharges the treated wastewater to the Irish Sea now that the new wastewater treatment plant is operational. This new pipe was brought by boat from Norway and was installed along the seabed during the summer of 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 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 is via gravity.
