A Western Australian-developed nutrient magnet that blocks damaging algal blooms would be applied to hot spots along the Canning River this month.
The locally designed and trialled clay, known as Phoslock, attracts and binds phosphorus so algae can’t use it, stopping the damaging blooms before they occur.
Up to 50 tonnes of the clay would be applied this week over a 2.5km stretch of the Canning River where phosphorus concentrations are high from urban and rural land use.
Environment Minister Donna Faragher and Water Minister Graham Jacobs today announced the start of the $180,000 project, being jointly managed by the Swan River Trust and the Department of Water.
Mrs Faragher said Phoslock was a proven and environmentally friendly mechanism for reducing algal blooms and was a critical part of the State Government’s $3.19million plan to improve the water quality of the Canning and Swan Rivers.
“This kind of State Government funding for problem areas in the Swan and Canning rivers can make a significant difference to improving the health of the waterways,” she said.
“The Phoslock project is just one of many initiatives being undertaken by the Swan River Trust as part of its catchment-to-coast approach to river management.
“The clay was last applied to the Canning River in January 2002, and effectively removed phosphorus to prevent blooms of potentially toxic blue-green algae.”
Water Minister Graham Jacobs said Phoslock had been developed by the Commonwealth Scientific and Industrial Research Organisation (CSIRO), in conjunction with the Swan River Trust and the Department of Water.
Dr Jacobs said the product had undergone extensive testing and appeared to be most effective in oxygenated areas of the river.
“This significant work has proven the worth of the product which is now approved for use in natural and drinking waters. It is being used worldwide as a corrective solution for nutrient rich waterways,” he said.
“Phoslock is sprayed as slurry, distributed from the back of a boat, removing phosphorus as it falls to the bottom. It settles to form a one-millimetre layer on the river bed, where it continues to strip dissolved phosphorus from the overlying water.
“It may cause the water to turn a milky colour for a couple of days, but it is not harmful to people swimming or fishing in the river.”
The sections of the river to be treated are upstream from the Kent Street Weir to about 800m beyond the Nicholson Road Bridge.
Environment Minister’s office - 9213 7250
Water Minister’s office - 9213 6900