
Valued for its ‘top-notch thinking and insight’ and ’deep and broad bench’, Torys’ environmental law practice also stands out for its comprehensive industry expertise, which encompasses the energy, infrastructure, forestry, mining and manufacturing spheres. Toronto-based department head Dennis Mahony is highly regarded for his work across the full scope of assessment and approval processes, administrative investigations and prosecutions and regulatory compliance. Mahony continues to steer Canadian National Railway through the federal environmental approval process for its Milton Logistics Hub. Alongside its activity in the transport sphere, the team leverages the firm’s formidable nuclear capability to excel in advising on the environmental aspects of nuclear projects — Toronto-based Michael Fortier is particularly prominent in this space. Other key contacts include Toronto-based climate change chair Tyson Dyck and Calgary-based litigator Lou Cusano, whose practice intersects energy regulation and environmental law. The team was recently strengthened by the arrival of counsel Claire Seaborn, who spent five years in senior government roles, including as Chief of Staff to the Minister of Energy and Natural Resources.
Legal 500 Editorial commentary
Testimonials
Collated independently by Legal 500 research team.
- ‘I work primarily with Dennis Mahony, who leads Torys' environmental practice. In my many years in the field, I have worked with many environmental lawyers across Canada, and there is no one I would want in my corner – or my clients’ corner – more than Dennis.’
- ‘Top-notch thinking and insight, high-quality service, deep and broad bench strength and an integrated team that works across disciplines to field the best expertise on the clients' behalf. Unlike some, Torys' is highly collaborative and respectful of the expertise of other (non-legal) professionals.’
- ‘Senior staff have lots of appropriate experience in the energy and nuclear industry. The senior nuclear regulator in Canada now works for the firm.’
- ‘The main person I continue to deal with is Michael Fortier. He is very well connected with the nuclear generators in Canada and he has an extensive knowledge of what the regulations say and what the regulators want.’
Key clients
- VIA HFR Wyloo ROFM Canadian National Railway Ontario Power Generation Resolute Forest Products/Domtar NOVA Chemicals Brookfield Asset Management
Work highlights
Advised VIA HFR on securing all the required major approvals for the Toronto-Quebec City Rapid Train Network Project, including under the Federal Impact Assessment regime.
Advised Canadian National Railway on mandates across the country, including on the federal environmental approval process for its Milton Logistics Hub.
Advised Ontario Power Generation on multiple matters, including on the Darlington Small Modular Reactor project.
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Practice head
Dennis Mahony
Other key lawyers
Tyson Dyck; Michael Fortier; Lou Cusano; Claire Seaborn; Jon Silver



