* Samples last week showed high uranium levels in lake
* CEO says pumping out uranium water would not be costly
* Expects authorities in next few months to decide what needed (Releads with CEO comments)
HELSINKI, March 12 (Reuters) - Finland’s Talvivaara said on Tuesday it will work with authorities to assess the need for a clean-up of leaked uranium found at the bottom of lakes near its Sotkamo nickel mine but does not expect such operations to be costly.
Nuclear safety authority STUK said water samples taken last week from Lake Salminen, near the mine in eastern Finland, showed uranium levels six times higher than levels advised for drinking water.
Chief Executive Pekka Pera said Talvivaara expected authorities overseeing its operations to decide during the next few months if the water should be pumped out or cleaned up.
“It would take a half of a day to pump out that amount of water and chemicals worth a couple of thousands of euros,” Pera estimated.
STUK said the levels of uranium in waters near the mine had decreased since the leak but the latest data suggested there was still a heavy concentration of pollution in some lakes.
STUK director Tarja Ikaheimonen said the uranium-affected water could begin flowing downstream in the spring as snow and ice begin to melt, though added it would not pose a significant threat to public health.
“I think these waters belong to the waters that need to be cleaned,” Ikaheimonen said.
Talvivaara said it expected the uranium and other leaked metals to remain settled at the bottom of the lake. Some nearby lakes such as Salminen have for a few years had a layer of salty water at the bottom due to high concentrations of sulphate, sodium and manganese.
Talvivaara is a pioneer in the use of bacteria to extract nickel in a process called bioheap leaching.
Yet even before its waste water leak last November, it suffered a series of setbacks including the death of a worker and excess rain water that forced it to halt ore mining and crushing last September.
The company is currently draining cleaned excess waters from the mine in an attempt to be able to restart mining and crushing operations.
Last Friday its shareholders agreed to stump up 261 million euros ($340 million) through a new share issue to keep the mine running.
$1 = 0.7684 euros Reporting by Terhi Kinnunen; Editing by Mark Potter and Jason Neely