Richmond River groundwater quality data revealed
RESEARCHERS from Southern Cross University led by a PhD student have undertaken critical research on the Richmond River to allow for long-term monitoring of its water health and quality.
The studies which describe the seasonal drivers of water quality in the mid-Richmond River, were part of a collaborative project funded jointly by the Northern Rivers Regional Organisation of Councils and SCU and allowed researchers to established baseline coal seam gas datasets for the Richmond River catchment.
Ms Atkins, who recently concluded her PhD research on this project, said the team found through the detailed water quality and carbon datasets on the Richmond River and its tributaries upstream of Casino and Kyogle, contained no large methane seeps in water as has been observed near active CSG fields in Queensland
Now she is the lead author on two internationally published papers, Assessing groundwater-surface water connectivity using radon and major ions prior to coal seam gas development and Seasonal exports and drivers of dissolved inorganic and organic carbon, carbon dioxide, methane and δ13C signatures in a subtropical river network/.
The research builds on recent baseline groundwater and atmospheric chemistry investigations published in 2015.
Ms Atkins said the first paper revealed that groundwater seepage drives the Richmond River flow most of the time and also identifies river segments where groundwater seepage is most prevalent and the second paper describes the carbon chemistry and how groundwater seepage releases greenhouse gases, including methane, to the river.
"Our research has taught us several lessons on how to perform baseline investigations in Australian rivers and groundwater," she said.
"We need to use methane as a key indicator of coal seam gas impacts on groundwater, rivers, and air."
Ms Atkins said the catchment-scale mapping of river water used novel isotopic techniques identified areas where groundwater is connected to the river.
"These techniques can be applied anywhere (including) areas where groundwater connects to river waters should be avoided for CSG development."
Baseline coal seam gas data established for Richmond River in NSW North Coast
Co-author Dr Damien Maher from the University's School of Environment, Science and Engineering said the Richmond River has long been a focal point of the team's research which commenced more than four years ago.
"Essentially the project was to gather some baseline information about water quality in the area and we now have one of the most comprehensive water quality and carbon datasets in any Australian river," he said.
"What this means is we want to know the methane concentration are in the water now, before any development has happened and we can use this to compare how things might change in the future."
Professor Isaac Santos from the University's National Marine Science Centre, one of the studies' authors, has been investigating methane sources for several years using mobile technology.
"CSG exploration has been suspended in the Northern Rivers region, but the resource remains in the ground," he said.
"Having quality baseline data is key to assessing long-term impacts of any development."
The researchers found no methane seeps along the Richmond River.
"While methane is high in some parts of the Richmond River, we found no methane seeps similar to the ones in Queensland," said Dr Santos.
"All methane in the Richmond River appeared to be from natural sources (and) we will be in a strong position to assess impacts on water quality if CSG activity comes to our region in the future."