Molendinar Backwash System & Electrical Upgrade

About the project

The Molendinar Water Treatment Plant is the largest treatment plant on the Gold Coast, servicing the majority of the region. Pensar was engaged for the upgrade of the backwash and electrical systems. This project is the largest upgrade to this treatment plant since it was built in the 80s and will ensure future capacity and reliability of the treatment plant, to service the growing community.

Key Capabilities

Water & wastewater treatment plant works, Low & high voltage installations, Specialised commercial, industrial, & municipal buildings

Project Location

Molendinar, Qld

Client Name


Project Duration

March 2018 - July 2019

Project Value

$5 Million

Project scope

  • Upgrade of the existing backwash system – pump and blower replacement and pipework modifications
  • Upgrade of the fire service water system
  • Upgrade of the existing electrical system – switchroom and switchboard upgrades
  • Construction of new blockwork building
  • Provision of new back-up power system
  • Removal of redundant mechanical, electrical and civil equipment and infrastructure
  • Modifications to the Control System and SCADA


  • Time frames were tight and fixed as the system had to be shut down for work to be completed
  • This project involved a complete shutdown of systems which had never been done before, with no instruction on how to take plant both offline and back online
  • The plant had to be taken offline for 10 weeks with not disruption to surrounding communities
  • Much of the work was undertaken by a large team in confined spaces, requiring careful management and coordination between the different teams


  • Coordination and planning with relevant stakeholders to shut down the entire WTP for 10 weeks
  • Successfully took the plant offline and back online, creating operation manuals for future works
  • Extensive planning kept the project on schedule, despite delays in the delivery of major equipment
  • Fabrication and connection of new DN750 mild steel pipework, valves and fittings into the existing filters
  • Pensar delivered the entire design and construct project utilising our electrical, mechanical, civil and structural capabilities
  • Implementation of innovative design methods, such as 3D models in order to explain necessary changes to the client
  • Project completed on time with no disruption to surrounding communities