Notice of Determination

Atomic Energy of Canada Limited (AECL) has determined that the proposed removal of the fuel storage tanks at AECL's Chalk River Laboratories site is not likely to cause significant adverse environmental effects. The removal of the fuel storage tanks, and associated systems represents a significant reduction in potential environmental liability at the Chalk River site.

Furthermore, with appropriate mitigation measures applied, the Environmental Effects Assessment determined that the proposed project is unlikely to cause significant adverse environmental effects.

In support of making this determination, the Environmental Effects Assessment considered the factors under section 84 of the Impact Assessment Act (IAA). Notably, Indigenous knowledge and identified value components helped to inform the assessment of impacts on the rights of Indigenous peoples. An early engagement and project review period occurred as part of existing relationship agreements to support knowledge and information sharing through working group discussions, document reviews and a tour of the project site. AECL and CNL have committed to additional site visits and ongoing engagement during and after project activities. 

The environmental effects determination also considered mitigation measures that are technically and economically feasible and that would mitigate any significant adverse environmental effects when implemented. An example of this involves Milkweed plants, a host plant to three different life stages of the monarch butterfly, an endangered species under the Species at Risk Act. These milkweed plants were identified within the project area and found hosting multiple monarch eggs and caterpillars. As a mitigation measure, the affected project area has been clearly flagged as a no-go zone to avoid disturbance. Further project activities in these areas will only be authorized after the September 25th safe mowing date for monarch butterflies and after a site inspection by a biodiversity specialist has been conducted. These dates are in line with the Roadside and rights-of-way mowing safe dates as referenced in the Environment and Climate Change Canada factsheet. With the application of established mitigation measures noted above, no adverse effects to the milkweed plants or the monarch butterfly is likely to occur as a result of the proposed project.

In addition to the factors under section 84 of the IAA, determination has been influenced by the following:

• The project will result in the removal of an existing environmental risk,
• The project activities are occurring on previously disturbed land, and
• The project will not cause harm to wildlife or the destruction of critical habitat.

All proposed project activities are to be carried out in accordance with CNL's policies and procedures, all applicable licences and permits, and applicable laws.

In conclusion, as the federal authority, AECL has determined that carrying out the Fuel Storage Tank Removal Project is not likely to cause significant adverse environmental effects and has instructed CNL to proceed with the project.