Project Outline

This project entailed a major refurbishment and expansion of Swords Wastewater Treatment Plant which an increase in capacity from 60,000 PE to 90,000 PE.

This project included:

• Full refurbishment of the preliminary treatment plant.
• New stormwater holding tank.
• 2 no. new high-rate upward flow primary settlement tanks.
• Additional secondary treatment capacity with 4 no. new SBR basins.
• New tertiary treatment plant comprising flow balancing tank, disc filters and UV disinfection plant.
• Full replacement of the existing sludge thickening plant with new drum thickeners and polyelectrolyte plant.
• New sludge dewatering centrifuges.
• Refurbishment and expansion of the anaerobic digestion plant.
• New odour abatement systems for the entire works

Key Challenges

The key challenge which was met on this project was to ensure that we succeeded in delivering the upgrade of the plant without any interruption in either available capacity or performance. This was achieved through consultation and close collaboration between the Murphy project delivery team and the Fingal County Council plant operation team.

Project Delivery & Innovations

• The refurbishment and expansion of the anaerobic digestion plant was designed to maximise renewable energy yield in the form of biogas from the sludge treatment process and minimise the carbon footprint of the plant.
• The 2 no. existing anaerobic digesters were fully refurbished and an additional 2 no. anaerobic digesters were constructed.
• Ultrasonic treatment of the sludge was installed and commissioned to enhance biogas production within the digestion process.
• A new biogas conditioning plant to remove hydrogen sulphide was installed.
• A new biogas holder was installed.
• 2 no. new 100kW CHP units.

Key Facts

• 50% increase in plant capacity delivered.
• Use of renewable energy in the form of biogas to power the plant maximised.
• Swords estuary environment protected by major improvements in effluent quality.