Upgrades at Windmill Hill Reservoir in Co Meath have addressed critical water infrastructure challenges that had caused frequent water outages for the commuter towns of Ratoath, Ashbourne and Dublin environs.
Nicholas O’Dwyer, an RSK Group company, has overseen the project on behalf of Uisce Éireann as consulting engineers and provided support from feasibility design to detailed design, construction and final commissioning of the work.
Replacing an ageing asbestos pipeline
Nicholas O’Dwyer principal consultant Damien Kennedy said the work involved replacing an ageing asbestos pipeline prone to bursts along with the construction of a new 4.7-million-litre treated water storage reservoir to overcome the shortages and disruption faced by residents.
Kennedy said: “Uisce Éireann needed to find a solution that would reliably ensure the water main can serve nearby communities and improve pressure and capacity to meet current and future demand.
"This was achieved by replacing 7km of ageing and burst-prone asbestos pipeline with modern, more durable infrastructure. To meet demand, a 4.7-million-litre treated water storage reservoir was also constructed with secondary chlorination facilities. Combined, these solutions offer a reliable and sustainable water supply that can withstand modern pressures and has the capacity to accommodate future growth demand.”
Throughout the work, the existing trunk pipeline remained operational to ensure customers had uninterrupted access to water services. “The fragile asbestos cement trunk pipeline was kept in continuous operation while engineers laid the new water main adjacent to the existing water main. This required meticulous planning and execution to ensure that interruptions to service throughout construction were minimised.
"It was possible to lay the new pipeline next to the existing one by using under pressure drilling techniques such as hot tapping. The hot tapping process enables connection to a pressurised system without shutting it down or releasing the pipeline’s content. This approach was of benefit because the works could continue without interrupting the water supply to several thousand customers.”
'Project took an integrated approach'
As well as completing the construction of the reservoir and trunk main work to ensure improved services, the project took an integrated approach to sustainability, including the installation of solar photovoltaic (PV) panels. Kennedy said: “During the design phase, the opportunity was taken to make the new site infrastructure as energy efficient as possible by building in energy-saving and sustainable technologies.
"The solar PV array will provide the energy required to run Windmill Hill with the capacity to generate 72,000kWh annually, equivalent to the average electrical consumption of 17 households. This will offset 10 tonnes of CO₂ emissions otherwise produced by the site through energy consumption, and any surplus energy can be exported back to the grid.”
Uisce Éireann portfolio manager William McKnight said: “Uisce Éireann is very proud to have delivered this important infrastructure, in conjunction with our engineering services provider, Nicholas O’Dwyer, as this project illustrates our commitment to improving water services in Meath.
"This significant investment of €19m by Uisce Éireann will support social and economic development while improving water supply security and resilience for homes and businesses in Ratoath, Kilbride and Ashbourne.”