Newport Wastewater Treatment Plant (2026)
Newport WwTP nearing completion - Courtesy of Ward & Burke
Newport Wastewater Treatment Plant is located approximately 1.5km south-west of Newport Town, close to the county boundary between Tipperary and Limerick. The facility is an asset of Uisce Éireann and is operated by Tipperary County Council under an existing Service Level Agreement. The original plant was constructed in the 1980s on a greenfield site. Prior to the upgrade, the plant was non-compliant with the requirements of the Urban Wastewater Treatment Directive (UWWTD) and the applicable Wastewater Discharge Authorisation standards (WWDA).
Existing works
The existing plant was designed to treat flows from a population equivalent (PE) of 1,900, and to achieve effluent discharge standards of 25 mg/l biochemical oxygen demand (BOD5), 35 mg/l suspended solids (SS) and 125 mg/l chemical oxygen demand (COD).
Treated effluent and overflow stormwater from the plant discharge to the Newport/Mulcair River via two separate adjacent outfalls located within the existing site. One outfall is dedicated to treated effluent, while the second discharges stormwater only.
The original treatment process comprised preliminary treatment by screening followed by secondary treatment consisting of a single oxidation ditch and a single clarifier. Sludge treatment facilities on site included 12 existing sludge drying beds.
(top left) Overview of existing works, (bottom left) existing clarifier tank and (right) the exiating oxidation ditch – Courtesy of Ward & Burke
Scope of works
The principal objectives of the Newport WwTP upgrade were to provide sufficient treatment capacity to accommodate planned development and population growth within the Newport agglomeration, while also delivering the improvement works required to achieve compliance with the Urban Wastewater Treatment Directive and the applicable wastewater discharge authorisation standards.
The existing treatment capacity of Newport WwTP was 1,900 PE. The upgraded process stream was designed to provide a 10-year design horizon capacity of 4,200 PE, while the proposed inlet works and underground structures were future-proofed for a 25-year design load of 4,500 PE.
This approach reflected the different service lives associated with civil structures and replaceable mechanical and electrical plant, including pumping systems, aeration equipment and blowers. Provision for future expansion of the mechanical and electrical systems will be subject to updated load projections, detailed design and a subsequent planning application.
The upgrade works comprised the construction of a new below-ground inlet works structure incorporating 6mm fine screens, a 19mm bypass screen, grit removal and classification equipment, screenings handling facilities, grease removal plant and an overflow chamber designed to limit flow to three times dry weather flow before discharge to the process tanks.
Newport WwTP process overview – Courtesy of Ward & Burke
The inlet works was sized for flows of up to 70 l/s. The contract also included decommissioning of the existing inlet works and associated storm overflow, extension of the gravity sewer to the new inlet works, and provision of a partially below-ground stormwater tank with associated pumps and pipework.
Additional treatment capacity was delivered through the construction of a new stormwater storage tank, a new oxidation ditch and a new final settling tank, both configured to maintain the existing hydraulic profile.
The scheme further incorporated ferric dosing for ortho-phosphate removal, underground splitter chambers upstream of the biological and settlement stages, a new motor control centre for the additional treatment stream, telemetry and control integration with the existing infrastructure, SCADA upgrades to reflect both new and decommissioned assets, and the connection of the new process stream to the live plant to enable phased testing and commissioning.
Permanent energy monitoring equipment was installed to support monitoring and verification of plant performance during operation.
New inlet works – Courtesy of Ward & Burke
Newport WwTP: Supply chain – key participants
Ward & Burke was appointed by Uisce Éireann in December 2022 as main contractor for the upgrade of the existing plant.
The contract included design, civil engineering, MEICA installation and plant operations during the commissioning and handover period.
- Client: Uisce Éireann
- Principal designer, contractor & project manager: Ward & Burke
- Employer representative: Tetra Tech RPS
- Resident engineer: Nicholas O’Dwyer Ltd
- PSDP H&S coordinator: TOBIN
- Ecologist: Flynn Furney Environmental Consultants Ltd
- Precast tanks: Shay Murtagh Precast
- Precast chambers: Tracey Concrete
- Screening & grit removal: Jacopa Ltd
- Lifting equipment: T Allen Engineering Services Ltd
- Diffused aeration system: SSI Environmental
- Pumps, mixers & fine bubble diffusers: Sulzer Pumps Wastewater Ltd
- Aeration blowers: AERZEN Machines
- Scraper bridges: Keltec Engineering
- Site metalwork: D&E Welding
- Washwater booster pumps: Campion Pumps
- PVC pipe: Total Pipeline Specialist
- Ductile pipe & fittings: Fusion Pipeline Products
- Actuators: AUMA Actuators Ltd
- Valves: Valve & Actuator Solutions
- Talis penstocks: AVK UK Ltd
- Odour control: CMI John Cockerill Environmental
- Ultrasonic meters: Pulsar Measurement
- PLC software & commissioning: Ward & Burke
- Kiosks: Gleeson Steel & Engineering
- Flow measurement: Siemens
- Flow switches: IFM Electronics
- Level switches: CPS
- Access covers: EJ Ireland
- Formwork: Mitchell Brothers
- Ready mix concrete: Kellys of Fantane
- Aggregates: O’Connell Quarries
Newport WwTP showing existing (red) and new (green) assets – Courtesy of Ward & Burke
Civil engineering works
The principal civils work and the corresponding construction methodologies adopted for the upgrade were as follows:
| Work element | Construction Methodology |
| Storm tank | Below-ground precast chamber |
| Aeration tank | Below-ground precast chamber |
| Final settlement tank | Below-ground precast chamber |
| Returns pump station | Below-ground precast chamber |
| Washwater pump station | Above-ground precast chamber |
| Inlet works & splitter chambers | Below ground in situ concrete |
Cofferdam construction for new aeration tank – Courtesy of Ward & Burke
Process technologies
Process technology selection focused on maintainability, operational efficiency and reduced water and energy demand.
The inlet works incorporated 6mm step screens, eliminating the requirement for dedicated process washwater and thereby reducing operational water consumption and associated carbon impacts. An air-lift grit removal system was adopted, comprising a stainless-steel coarse-bubble diffuser arrangement and stainless-steel grit lift pipework. Because the system contains no submerged moving parts, routine maintenance can be carried out without tank entry; improving both safety and maintainability.
Biological treatment efficiency was supported through the use of 9-inch fine-bubble diffusers supplied by SSI Environmental, selected to provide high oxygen transfer efficiency and energy-efficient aeration.
In addition, a final effluent service water system was installed to reuse treated final effluent for washwater duties at the inlet works launders, grit classifier and screenings handling equipment. This system comprised a buffer tank, booster pumps, valves and associated pipework, and removed the need to use potable water for these process functions.
New aeration tank – Courtesy of Ward & Burke
Key challenges
Project delivery was complicated by the need to undertake the works within an operational wastewater treatment plant while maintaining continuous treatment performance. Significant construction risk was also associated with the installation of large underground structures to depths of up to 5m in silts and gravels, with variable groundwater conditions influenced by the proximity of the adjacent river.
These challenges were further intensified by the requirement to complete the design-and-build scheme, including commissioning, within a programme duration of 550 days.
Conclusion/summary
The upgraded plant was commissioned in June 2025, with operation scheduled to transfer from Ward & Burke to Uisce Éireann in June 2026. Overall, the project delivered a substantial improvement in treatment performance, hydraulic capacity and operational resilience for Newport Town.
The upgraded works provide improved effluent quality through the replacement of inadequate existing treatment assets, enhanced protection of receiving water quality in the Newport/Mulcair River, and additional treatment capacity to support forecast population growth and planned development within the agglomeration.
The integration of new civil, mechanical, electrical, instrumentation, control and automation systems has also improved maintainability and operational robustness, while moving the plant closer to full compliance with the Urban Wastewater Treatment Directive and EPA wastewater discharge licensing requirements.
(left) New stormwater tank and (right) final settlement tank under construction - Courtesy of Ward & Burke
