May 22, 2025 – During Port Hope Area Initiative (PHAI) work at the Port Hope Long-Term Waste Management Facility, it was observed that stormwater from the western portion of the site was flowing outside the site boundary. As a result of recent heavy rainfall, stormwater storage capacity was exceeded and approximately 10,000 litres of untreated water was released off site into a ditch at a road allowance adjacent to the site.
CNL took immediate action, adding additional pumps to process the water. Redirection of water away from the area also reduced the flow of water. Water samples were collected for analysis to confirm that the risk to the environment was negligible.
CNL notified the appropriate regulatory agencies, including the Canadian Nuclear Safety Commission (CNSC), Ontario Spills Action Centre and the Ministry of the Environment, Conservation and Parks, as well as the Municipality of Port Hope.
There was no risk to the safety of workers or the public from this event.
Note:
The initial estimates for water released from site was based on visual observations by field staff. During the investigation into the incident CNL determined a revised estimate of 10,000 L based on review of all available information from the event. The investigation revealed that the duration and flow rate were greater than originally reported. Original notifications and disclosures have been updated to reflect the revised water volume.