Nepean Water Filtration Plant

NSW
Sydney Water
In progress

The Nepean Water Filtration Plant (WFP) Upgrade will increase the plant’s production capacity to meet future demand while improving overall treatment reliability. Delivered as part of the West Region Delivery Team (WRDT), the project includes a new parallel process train and upgrades to existing systems to strengthen treatment performance, resilience and regulatory compliance.

Scope of works

The upgrade includes the delivery of a new treatment stream parallel to the existing process, along with modifications to key supporting infrastructure. The works involve:

  • Construction of a new treatment train, including rapid mix, flocculation tanks, lamella settlers, dissolved air flotation units and dual media filters, before re-joining the main process at the clear water tank.
  • Installation of new chemical dosing systems and upgrades to existing ferric, polymer and carbon dioxide systems.
  • Relocation and modification of existing assets to enable tie-ins and integration with the live plant.
  • Delivery of new electrical infrastructure, including high and low voltage switch rooms, transformer and generator facilities.
  • Sitewide civil works, including earthworks, drainage, yard piping and internal roads.
  • Integration of SCADA systems.
  • Design, construction, commissioning and handover of all new assets.

Working within a live treatment plant

A key challenge for the team delivering the upgrade at the Nepean WFP is delivering works within a fully operational facility. The construction has been carefully staged to minimise disruption to the production of drinking water, with temporary works, detailed access planning and strict operational controls implemented to ensure safe and continuous plant operation. With limited space for access, laydown, and material movements, crews are working within tight boundaries and active operational areas, requiring meticulous planning and ongoing adjustments to maintain safety and progress.

Complex integration with existing infrastructure

Integrating new assets into a live treatment plant requires detailed planning and close collaboration with operations. Complex tie-ins are carefully scheduled within short, tightly controlled shutdown windows to minimise operational impacts, while staged electrical and control system upgrades, including new high and low voltage infrastructure, demand precise coordination with live networks. SCADA integration involves phased cutovers, updates to existing control systems, and rigorous testing under operational conditions to ensure seamless performance. 

Commissioning and process validation

The new treatment processes, including lamella clarification, dissolved air flotation units, and multiple dual media filters, will be thoroughly commissioned and validated to meet performance and water quality requirements. This involves a detailed process of proving, testing, to ensure alignment with Australian drinking water treatment guidelines.