The assets audit and sediment contamination testing were carried out at four WSUD sites within Banyule Council to determine the level of contamination for different parts of the stormwater management system, assess sediment types broadly, estimate sediment extraction volumes and measure water depths.
The sediment samples in wetlands and ponds were taken at intervals of 4 - 5 metres and analysed to inform the development of the optimal method for asset cleaning with an accent on safety. The three test types conducted were:
EPA Screen Test - Vic EPA IWRG 621
TRH with Silica wash - Total Retreviable Hydrocarbons (TRH) with Silica wash, BTEXN - TO test for organic contamination not caused by rotting leaf litter
Heavy Metals - M17 : Extended Metals Suite
The Findings and Recommendations reports had been issued to the Council outlining the water and sediment depths, disposal volumes for cleaning, cleaning priorities and work methods and disposal and recycling options. The site work is scheduled to start in 2021.