Maintenance and Cleaning of Trash Racks and Floating Litter Booms

The Adelaide and Mount Lofty Ranges Natural Resources Management Board (the Board) has constructed a number of net style trash racks and floating litter booms on drains, creeks and rivers in the Patawalonga and Torrens catchments. In addition the Board is responsible for the cleaning of the steel grille on the upstream end of the “Barcoo Outlet” which is located at the northern end of the Patawalonga Lake and the steel trash structure on the outlet of the Sturt Flood Control Dam which is built on the Sturt River at Flagstaff Hill. This contract is for the cleaning and maintenance of all of these facilities.
The trash racks and booms play a very important part of the Board’s overall program of water quality improvement by removing unsightly debris, raising community awareness and by improving river health through the removal of large quantities of organic matter that would otherwise deplete oxygen and raise nutrient levels in the waterways.
Many of the trash racks and booms are located in places where they are very visible and consequently require frequent and prompt cleaning to remove debris. It is particularly important that debris collected in the trash rack and booms be removed and disposed of as soon as practicable after it has been caught. It is also important that the cleaning work be done in a manner that is sensitive to the environment and nearby residents.
The racks collect mainly vegetable matter (leaf litter, branches, reeds etc) and silt, but litter and occasionally large items such as bricks, tree branches, garbage bins, items of furniture, etc, may also be captured.
It is anticipated that the trash racks and floating boom will together collect around 500–1000 tonnes of debris each year and debris needs to be removed from every trash rack up to around 30 to 40 times in a year. Details of the historic cleaning schedule are available.
It is vital that trash racks and their immediate surrounds are cleaned promptly after rainfall and that they are kept in a condition to ensure maximum capture efficiency at all times.