Floodplains in the Hunter Valley have been inundated with floodwaters after the recent significant heavy rain which has resulted in a blackwater event causing fish deaths and odours.
There have also been dam wall collapses at two Hunter Valley coal mines – Peabody Energy’s Wambo mine and Rio Tinto’s Warkworth mine.
EPA Director North Gary Davey said the odours around Newcastle are caused by natural processes due to low levels of oxygen in the Hunter River.
“Firstly, there are no coal mines in either the Paterson or Williams River catchments,” he said.
“Testing also shows that Dissolved Oxygen levels in waters coming down the Hunter River were considerably higher than the DO levels in the area where the fish kills occurred, for example 40% at Morpeth and 1% at Raymond Terrace.
“Assessment of salinity data from upstream to downstream has also identified that saline water discharged from mines as part of the Hunter River Salinity Trading Scheme has not caused the fish deaths.
“Unfortunately, it will be still some time before the impacts of the blackwater event dissipate and the river starts to return to normal. We have requested councils to conduct clean-ups of the dead fish, but in the meantime, the community is reminded to continue to exercise caution around the river and any stagnant waters.”
EPA and Office of Environment and Heritage (OEH) will continue testing waters and monitoring the blackwater over the coming days.