Arklow Wastewater Plant sets new standard for sustainable infrastructure

The Arklow Wastewater Treatment Plant – a €139 million project that ends decades of raw sewage discharge into the River Avoca – has officially opened, marking a major environmental milestone for Ireland.

Ayesa, a global leader in engineering and technology, joined Irish Water utility Uisce Éireann, An Taoiseach Micheál Martin, Minister James Browne, and local representatives to celebrate this long-awaited achievement.

Strategically located in Ferrybank on Ireland’s east coast, the state-of-the-art facility brings long-overdue environmental protection to the region while unlocking potential for future housing and commercial development in Arklow and its surroundings.

Fully operational since late 2024, the project was delivered six months ahead of schedule and within budget—an exceptional achievement in major infrastructure delivery.

In a striking departure from conventional wastewater facilities, the Arklow plant has captured international attention for its bold design and architectural excellence.

Blending industrial function with sculptural form, the building integrates seamlessly into its coastal setting with a design that is both practical and visually compelling. It was recently awarded the prestigious Downes Medal—the highest honour from the Architectural Association of Ireland, and one rarely granted to utility infrastructure. This recognition positions the plant as a global case study in how essential infrastructure can also enrich the built environment.

“This project has been a decade in the making, and I couldn’t be prouder of the Ayesa (formerly ByrneLooby) team,” said Luke O’Connor, Director of Water, Ayesa Ireland. “Their dedication—from the earliest feasibility studies to project handover—has shaped a facility that is now a global benchmark in wastewater infrastructure.”

Ayesa has played a central role in this nationally significant project for over a decade, supporting Uisce Éireann and its delivery partners from inception to completion. The company’s multidisciplinary expertise spanned early environmental studies, land acquisition, and stakeholder engagement, through to the design of interceptor sewers, a marine outfall, and key infrastructure components, including a 1,000m offshore pipeline, river tunnel beneath the Avoca and high-capacity pumping station.

During construction, Ayesa acted as Employer’s Representative, overseeing delivery and ensuring seamless coordination across all stakeholders. Michael Looby, Director at Ayesa added: Being here on the first day we turned the sod and now to see the plant fully operational—ahead of schedule and already making a difference for the community—is incredibly rewarding. This is more than just infrastructure; it’s a legacy project for Arklow and it’s deeply personal to us.”

Michael Tinsley, Wastewater Senior Portfolio Delivery Manager, Uisce Éireann, said: “The successful delivery of the Arklow Wastewater Treatment Plant marks a major milestone for the community and for Uisce Éireann. Ayesa’s collaborative approach with all stakeholders, and technical expertise were vital to progressing this complex and long-anticipated project.”

Speaking at the event, the Irish Prime Minister, An Taoiseach Micheál Martin praised the project as a key step in Ireland’s environmental and housing ambitions. He said: “The Government recognises the vital role of strategic infrastructure investment in meeting the country’s demand for housing while also protecting and enhancing the environment. That’s why we are committed to working with Uisce Éireann to bring forward essential projects like this plant in Arklow, which is currently capable of supporting a population of 24,000 but holds the potential to expand to 36,000.”

With the plant now fully operational, Arklow is entering a new era—one defined by environmental protection, improved public health, and sustainable growth. More than just a treatment facility, this project stands as a model for how essential infrastructure can create long-lasting social, environmental, and architectural value.