Analysis of sampling data from the Port Granby Waste Water Treatment Plant for August 18 showed a level of 6 micrograms/litre (µg/L) for copper, which is above the action level of 5 µg/L but below the regulatory release limit of 10 µg/L. All other sampling parameters were below their respective action levels.
Action levels are set conservatively to act as an early warning system prior to any discharge into Lake Ontario. As such, this action level exceedance did not pose a risk to human health or the environment.
Following a review of possible contributing factors, mitigation measures have been introduced. CNL notified the Canadian Nuclear Safety Commission of this sampling result.