Claims of a radioactive leak at ERA's Ranger uranium mine have sparked calls for a safety overhaul

TRADITIONAL owners at Kakadu will oppose Energy Resources Australia's plans to expand the Ranger uranium mine unless the company can make what they say are necessary improvements in its environmental performance, following revelations of radioactive waste leaking into wetlands in the World Heritage-listed national park.

The warning comes after samples taken by the Environment Department early last month showed high levels of electrical conductivity were found in water flowing downstream from the mine into Kakadu's Magela Creek.

While he concedes the leak came from Ranger, ERA boss Rob Atkinson says the two spikes were related to salinity and were not hazardous.

"There was nothing unusual in terms of uranium measurements at all," he says.

"There has been nothing over that period of time to suggest that we have impacted on the surrounding environment."

But the body representing the traditional owners, the Gundjeihmi Aboriginal Corporation, rejects the salinity claims as misleading.

"That's very cute," GAC executive officer Justin O'Brien tells Inquirer. "Electrical conductivity measures the total amount of soluble material in the water. Uranium sulphate is one such soluble material."

High EC readings are normally associated with a contamination event. "It is misleading for ERA to be categorically saying this was not uranium because they don't know," says O'Brien. "In all likelihood this was a leak of uranium and other contaminants from the mine site."

The GAC wants ERA to overhaul its monitoring regime to include real-time monitoring of pollution, saying the delay in analysing weekly grab samples allows contamination to go unnoticed or unreported.

Senior Mirarr traditional owner Yvonne Margarula, who led the push against the Jabiluka mine, accuses ERA of telling the community "half truths" about the environmental impact on an area where children fish and swim.

"They don't tell us properly," Margarula says. "Only just half and half. All the good stuff."

Mirarr traditional owners have vowed to oppose a proposed expansion of the mine, including a heap leach facility and the extension of mining in the so-called Ranger 3 Deeps area, until ERA has "genuinely and demonstrably improved its environmental performance".

Relations between traditional owners and ERA may have improved since the Jabiluka dispute, but Ranger's environmental record remains a sore point.

In December last year, an engineered dam collapsed, spilling six million litres of radioactive water into creeks that flow into Kakadu.