Melbourne Water manages stormwater quality treatment systems to deliver stormwater flowing from urban areas. Wetland sediment ponds form a significant component of these systems (as part of a broader treatment train).
Melbourne Water regularly removes sediment from its wetland sediment ponds. When sediment is removed, the sediment is sampled and analysed for contamination. A small amount of the clean-fill sediment is reused on site, but the bulk of the clean material and all the contaminated material is removed offsite and disposed to landfill which incurs costs, including a landfill levy.
NCE and Alluvium were engaged to build on the work that has already been undertaken, by providing a more detailed analysis of Melbourne Water’s current and future sediment removal and landfill costs, and opportunities to manage these costs.
Desktop analysis of Melbourne Water datasets was accompanied by a review of relevant legislation and government policy. Current and future landfill costs were estimated. Case studies were also developed to highlight the range of costs incurred from managing these assets.
The project findings will be used by Melbourne Water to review and improve its wetland sediment removal program in consultation with the Government departments and agencies who determine landfill levies.