A filter at a wastewater treatment plant managed on behalf of client, Yarra Valley Water

A focus on ongoing safety improvement, reduced plant outage time and cost savings were at the forefront of an innovative solution introduced by Ventia's Mechanical and Electrical team delivering services for Yarra Valley Water. 

The team successfully completed a trial at a wastewater treatment plant to replace 'tertiary filter media' with an innovative approach. Filter media is anything placed in a filter that changes the quality of the water flowing through it. A tertiary filter is the final filter in a typical activated sludge treatment plant. It works in a similar way to a common household water filter, where sand and charcoal is used to filter and remove any suspended solids before the water undergoes a final disinfection with UV light to remove any pathogens.

The trial took place at Yarra Valley Water's Brushy Creek Wastewater Treatment Plant in eastern Melbourne where four 3 x 7 metre tertiary filters required their periodic charcoal media upgrade.

Previously, to complete the filter media upgrade, two workers were required to undertake a process that identified and controlled risks yet in contrast, with the new solution risks have either been reduced or eliminated altogether.

A worker in a cage is lowered into a filter

The newly trialled approach used a crane to lower one worker in a cage into a filter. Rather than releasing a large quantity of charcoal from overhead, a 'blower truck' hose was used to blow the material into the filter.

The safety benefits of this new method include:

  • only one, rather than two, workers required to enter a confined space
  • working from a cage eliminates the risks associated with working in a confined space and at heights 
  • charcoal from the blower truck is mixed with a small amount of water greatly improving dust suppression.

For the final filter, the crew trialled the use of an extension hose on the blower and completed the task standing on a permanent overhead gantry. This method eliminated the need for the cage and for a person to enter the confined space altogether and looks promising for further safety and productivity improvements.

The new procedure took less than a day to deliver, as opposed to approximately two to three days using the old method. Aside from the cost savings with this time reduction, Yarra Valley Water's plant outage time was decreased.

"Using this new method Ventia has been able to increase the efficiency, and continue to improve safety and quality of the operation," says Ventia's Electrical and Instrument Technician, David List.

Additionally, we were able to effectively complete the final filter cell without using a cage at all, setting a new benchmark for future installations by increasing safety and further reducing cost.

A filter at a wastewater treatment plant