Environmental regulators for the office of the Supervising Scientist admitted to a Senate Estimates committee today that water with uranium concentrations 400 times background and a cocktail of other radionuclides are seeping from beneath the tailings dam at the Ranger Uranium Mine in Kakadu National Park.

The Office of the Supervising Scientist acknowledged to Australian Greens Senator Scott Ludlam that the contamination was occurring, and said that the estimated amount of 100,000 litres per day was based on modelling and not measurement.

"The biggest surprise is that despite knowing about this leakage for years, the regulators don't know how much is seeping, where it is going, or how highly contaminated it is. The regulator suggested that directly sampling this contaminated water would be 'impractical.' I suggest that it is now essential."

"The regulator also admitted it would be impossible to completely rehabilitate the site, suggesting instead it would be cleaned up to some undefined 'reasonable' standard.

"The mining company ERA booked a 2009 profit in excess of $270 million dollars, and yet the regulator won't compel them to undertake any water quality sampling under the tailings dam. That has to change."

"Any moves by ERA to build another tailings dam of this kind in Kakadu must be stopped until the nature and magnitude of the existing leakage is known," Senator Ludlam said.

Media Contact: Fernando de Freitas 0417 174 302


Note: Uranium is only one of a number of radioactive elements present in the tailings dam - a more complete list is shown below.

Symbol          Element         Radiation       Half-Life       Decay Product
U-238   Uranium-238     alpha   4,460,000,000 years     Th-234
Th-234  Thorium-234     beta    24.1 days       Pa-234
Pa-234  Protactinium-234        beta    1.17 minutes    U-234
U-234   Uranium-234     alpha   247,000 years   Th-230
Th-230  Thorium-230     alpha   80,000 years    Ra-226
Ra-226  Radium-226      alpha   1,602 years     Rn-222
Rn-222  Radon-222       alpha   3.82 days       Po-218
Po-218  Polonium-218    alpha   3.05 minutes    Pb-214
Pb-214  Lead-214        beta    27 minutes      Bi-214
Bi-214  Bismuth-214     beta    19.7 minutes    Po-214
Po-214  Polonium-214    alpha   1 microsecond   Pb-210
Pb-210  Lead-210        beta    22.3 years      Bi-210
Bi-210  Bismuth-210     beta    5.01 days       Po-210
Po-210  Polonium-210    alpha   138.4 days      Pb-206
Pb-206  Lead-206        none    stable  (none)

Based on process water uranium concentrations of 27,000 parts per billion compared to 3-5 parts per billion in Coonjimba Billabong