lake Ontario of Canada is in a perilous condition due to leakage of nuclear waste from a facility managed by Cameco Corporation, the world's biggest supplier of uranium. The leakage of toxic substances such as arsenic and uranium from the storage site of Cameco at Port Granby has been going on for the past two decades, states a report of the Lake Keepers Ontario, an environmental watchdog group. "The storage site is not in compliance with environmental laws, although it is licensed by the federal government,' said Mark Mattson, author of the report. "Liquid radioactive wastes are constantly entering the lake in the form of intentionally discharged treated effluent and as fugitive seeps,' he wrote. According to the report, two series of tests conducted in 2000 showed that 63 per cent and 97 per cent of the water fleas placed in the treated discharge died. Water fleas are commonly used in Canada to determine toxicity, and if over 50 per cent of the organisms die the sample is considered "acutely toxic'. However, Cameco has denied the charges. "We have been meeting all the regulatory requirements,' said Jamie McIntyre, spokesperson for Cameco.