Results of routine sampling conducted on effluent (treated water) from the PHAI Waste Water Treatment Plant in Port Hope for the week ending June 7 showed that arsenic exceeded the action level.
Action levels are an internal threshold set well below the CNSC’s regulatory weekly discharge limit. The action level for arsenic is 41 micrograms/litre, and sample results were slightly elevated at 41.5 micrograms/litre. Results of other sampling parameters were in compliance with all limits.
On receipt of the results, CNL began investigative sampling to determine the cause of the exceedance.
CNL notified the Canadian Nuclear Safety Commission (CNSC) of the action level exceedance.