Tetra Tech provided engineering services for the refurbishment/expansion of the water treatment works at Ballymore Eustace to meet future demand and regulatory standards.
Tetra Tech was appointed by Dublin City Council in 2004 to complete the detailed design, procurement and construction supervision of the Stage 3 development of the Ballymore Eustace Water Treatment Plant. The development included a combination of existing plant refurbishment and new plant construction to achieve a sustainable output of 318 Million Litres/Day (MLD) (400 MLD peak output).
The critical objective of the City Council was to achieve the 318 MLD output as early as possible in the contract period to ensure the increasing water demands of the Greater Dublin Region could be met. This requirement necessitated the construction and commissioning of the new treatment elements in advance of the existing plant refurbishment, while maintaining full operational capacity at the plant throughout the contract period.
Challenge
From the inception of the project, the client outlined that “the production of quality potable water from the plant could not be compromised or interrupted by the construction activities”, and that “unrestricted and safe access to all operational elements of the plant was to be provided”.
All contract works were to be undertaken on or adjacent to the live treatment plant, including works on all the main treatment elements.
The 318 MLD capacity was to be achieved as early as possible during the contract. The design was required to maintain the existing gravity flow through the plant.
Solution
A detailed hydraulic model of the permanent and temporary works was developed to ensure plant capacity was maintained at all times. The design included an extensive by-pass system to facilitate full uninterrupted access to plant elements in case of failure or emergency. The design’s core concept sought to conserve head through the innovative use of hydraulic engineering, thereby minimising the energy required to treat the water and maximising the head available to facilitate its distribution throughout the Greater Dublin Region.
The Tetra Tech team designed and implemented contracts, which provided a structured sequence of works, target milestones and detailed construction constraints. The construction programme and access arrangements were continually reviewed and optimised through continuous collaboration between the Client, Contractors and Tetra Tech. Value engineering proposals were encouraged and implemented where practical.
All contract works were completed without unplanned interruptions. One planned 5-hour plant outage was required for the final treated water outlet connection.
At a glance
Client
Dublin City Council / Irish Water
Location
Dublin, Ireland
Services
Commissioning, contract administration, detailed design, site supervision, tender assessment, tender document preparation
The project featured in this article was undertaken by RPS, A Tetra Tech Company and originally published on RPSgroup.com. In March 2026 RPS rebranded to Tetra Tech.