An innovative trial using a clay treatment devised by WA scientists is helping improve water quality in the Peel-Harvey estuary.
Scientists from the State Government-funded Healthy Estuaries WA applied a specially manufactured clay-based treatment to a drain in the catchment of the estuary (Bindjareb Djilba), which successfully bound up to 95 per cent of phosphorus at the treatment site, preventing it from fuelling algal growth in the downstream waterways.
Many waterways, such as Serpentine River (Waangaamaap Bilya) — which flows into the estuary — can receive excess phosphorus from fertiliser use, potentially causing algal growth that can lead to fish kills and adverse human health impacts.
The Department of Water and Environmental Regulation has been working on a novel clay known as Hydrotalcite clay, or HT-clay, made from a natural bentonite clay modified with hydrotalcite: a phosphorus binding mineral.
The manufacturing process involves mixing together several raw ingredients, causing chemical reactions where the clay becomes coated in the phosphorus binding material.
Water Minister Simone McGurk said the phosphorus binding clay was an innovative WA invention.
“The ground-breaking research in the Peel-Harvey estuary complements the important work Healthy Estuaries WA is doing to reduce the amount of fertiliser applied to farms,” she said.
“While there is much work happening in the catchment to reduce nutrient inputs for the future, this is showing promising signs of how to address the high levels of nutrients that are polluting some of our waterways right now.”
Mandurah MLA David Templeman said the estuary was “the heart” of Mandurah’s community and work was needed to improve water quality so it could “continue to be the lifeblood of our community for generations to come”.
“This trial demonstrates that there are many tools available to us to improve water quality, and we need to make use of them all to achieve significant nutrient reductions for the Peel-Harvey estuary,” he said.