A proposal to mine uranium in Western Australia's northern Goldfields region has been rejected by the state's environmental watchdog.
Environmental Protection Authority chairman Tom Hatton said the Yeelirrie project owned by Canada's Cameco could not meet one of nine key environmental factors examined by the independent board.
Dr Hatton said the project, which was previously owned by BHP Billiton, would threaten subterranean fauna, which were particularly abundant at Yeelirrie, with 73 species recorded.
"Despite the proponent's well considered management strategies, based on current scientific understanding, the EPA concluded that there was too great a chance of a loss of species that are restricted to the impact area," he said.
Cameco said it respected the EPA's findings and acknowledged the complexity and uncertainty involved with assessing subterranean fauna.
"Sampling and impact management for subterranean fauna at Yeelirrie is very complex and this is reflected in the EPA's findings," managing director Brian Reilly said.
"We believe that with further sampling and research, subterranean fauna can be appropriately managed at Yeelirrie and we will work with government agencies and stakeholders to find a way forward."
The Conservation Council of WA and the Australian Conservation Foundation welcomed the EPA's decision.
"The EPA recommendation has been met with great relief among pastoralists, Aboriginal communities and environment groups who continue to campaign against uranium mining in WA," CCWA nuclear free campaigner Mia Pepper said.
"This is an important decision that highlights the importance of extensive surveying for subterranean fauna and acting to prevent extinctions."
The EPA report to WA Environment Minister Albert Jacob is now open for public appeal until August 17.
Cameco said it was "taking prudent steps" to prepare its uranium projects, which include the Kintyre project in the Pilbara region, for better market conditions.
The company secured environmental approval for Kintyre, which it acquired from Rio Tinto, in April last year.
Toro Energy's Wiluna uranium project, 960 kilometres northeast of Perth, was the first uranium project in WA to receive federal government approval since the state government lifted Labor's ban on uranium mining, imposed in 2008.
