Mardi Water Treatment Plant

NSW
Central Coast Council
In progress

Abergeldie is delivering a major upgrade at the Mardi Water Treatment Plant (WTP) for Central Coast Council. This project was awarded following a thorough Early Tender Involvement process, during which Abergeldie identified value engineering opportunities. The update aims to improve the plant’s capacity to provide safe drinking water, supporting the growth of the Central Coast region while also fulfilling inter-region transfer commitments. The scope includes designing, constructing, testing, and commissioning upgrades to the Water Treatment Plant.

Scope of works

The scope of works involves:

  • The conversion of existing tanks and replacement of mixers.
  • The installation of new systems for flocculation and dissolved air flotation (DAF).
  • The decommissioning and removal of outdated storage and dosing facilities.
  • The installation of new storage, batching, and dosing facilities.
  • Enhancements to the clearwater tank to increase efficiency.
  • Removal and repair of existing pipework and overflow structures.
  • Electrical, instrumentation, and control works associated with the upgrades.
  • Updates to PLC, SCADA, and network hardware and software.
  • Mechanical works associated with the project.

Planned shutdowns enabling critical works

Four major shutdowns have been successfully completed at the Mardi Water Treatment Plant with no impact on customers. Close collaboration with the plant’s operations team enabled these shutdowns to be carefully planned and managed, mitigating disruption to the water supply while critical tie-ins, equipment replacement, and structural upgrades were delivered safely. These works strengthened existing assets, improved operational flexibility, and ensured remaining upgrades can proceed efficiently.

Innovation improving delivery

Innovation is driving performance on the project, including the use of robotic crushing machines to improve safety during demolition significantly and a custom commissioning application that streamlines testing and commissioning, supporting efficient delivery under brownfield conditions.  

Dissolved Air Flotation system upgrade

A key component of the upgrade is the introduction of Dissolved Air Flotation technology, supported by new flocculation tanks, to strengthen treatment performance when the incoming water quality is poor.

The system improves turbidity removal and provides a robust solution for algae management, enabling the treatment plant to continue operating during algal bloom events and reducing reliance on the region’s drought contingency storage.

Long-term community benefit

Upon completion, this highly complex upgrade will deliver up to 160 million litres of high-quality drinking water daily, benefiting over 200,000 residents on the Central Coast of New South Wales. This significant enhancement ensures a reliable and sustainable water supply for the growing local community.

This landmark development is supported by a $6.85 million investment from the NSW Government’s Restart Safe and Secure Water Program, along with over $75 million from Central Coast Council, to secure the region’s water future.