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Patrick G. Welsh

Patrick G. Welsh

Associate, Regulatory, Environmental, Aboriginal and Land; Litigation

Contact Information

tel: 416.862.5951



Bar Admission

Ontario, 2011

  • Queen’s University, J.D.
  • Queen’s University, M.A.
  • Queen’s University, B.A. (Hons.) (Biology and History)

Patrick is a member of Osler’s Regulatory, Environmental, Aboriginal and Land group, and is a member of Osler’s Litigation Department. 

Patrick provides advice on business issues relating to environmental matters, including waste diversion, transportation of dangerous goods and hazardous wastes, emissions and discharges, contaminated lands, records of site conditions, risk assessments, maritime pollution and spills, regulatory orders, waste and soil, asbestos and other designated substances, and general environmental regulatory compliance. He regularly works with environmental consultants to address clients’ business needs. 

Patrick also has experience in regulatory proceedings before the Ontario Energy Board, on electricity transmission and distribution matters and on natural gas distribution matters, including applications involving regulated asset sales and transfers, gas franchise agreements, certificates of public convenience and necessity, and various rate-setting proceedings.  Patrick has also advised on Aboriginal law issues, including on capacity funding and benefits agreements, and on anti-corruption and anti-bribery matters.

Patrick is cross-appointed to the International Trade group, and has experience in procurement challenges before the Canadian International Trade Tribunal and the Federal Court, and has been involved in multiple internal investigations pursuant to Canada’s anti-corruption and anti-bribery laws.

He has appeared before the Ontario Environmental Review Tribunal, the Ontario Municipal Board, the Ontario Superior Court (Commercial List), the Ontario Court of Appeal, the Federal Court of Canada, and the Federal Court of Appeal.

Patrick joined the firm as a summer student in 2009 and articled with the firm in 2010-2011, during which time he was seconded to the legal department of the Royal Bank of Canada.

    • TransCanada Pipelines in land acquisitions and land use planning and development matters related to Ontario pipeline projects.
    • Association of Power Producers of Ontario in the Ontario Energy Board proceeding to set export transmission service rates in Ontario.
    • An American consulting firm in an active lawsuit involving negligence issues relating to the decommissioning of contaminated lands, including issues relating to professional liability, standard of care, pure economic loss, and the alleged stigma of contamination.
    • A US corporation in an active appeal to the Environmental Review Tribunal from an order issued by the Ontario Ministry of the Environment relating to a closed industrial landfill in northern Ontario.
    • A US automotive manufacturer in multiple environmental matters relating to emissions and discharges and the transportation of dangerous goods
    • Natural Resource Gas Limited in multiple matters before the Ontario Energy Board, including the renewal of natural gas franchise agreements with several municipalities
    • An international agricultural equipment manufacturer in product stewardship and waste diversion matters
    • Rapiscan Systems Inc. in a successful judicial review of a multi-million dollar procurement decision by the Canadian Air Transportation Security Authority
    • The Underwriters in Cara Operations Limited’s $230 million initial public offering
    • Ventas Inc. on its $980 million acquisition of 29 independent living seniors housing communities across Canada from Holiday Retirement Corp.
    • A pro bono client in an active appeal to the Environmental Review Tribunal from an order by the Ontario Ministry of the Environment relating to alleged waste ash used as fill

  • Agnes Benidickson Tricolour Award (2010)
  • Gavel Award (2010)
  • John D.B. Walton Scholarship in Administrative Law (2010)
  • Davies Ward Phillip Vineberg LLP Prize in Corporations and Taxation (2010)
  • R.W. Leonard Prize in Alternative Dispute Resolution (2009)
  • David Sabbath Prize in Contract Law (2008)
  • Aird & Berlis LLP Award for Academic Achievement (2008)
  • Dean’s Silver Scholar Award (2008)

  • Law Help Ontario, Duty Counsel Volunteer

  • The Advocates’ Society
  • Canadian Bar Association
  • Ontario Bar Association
  • The Osgoode Society for Legal History

  • NEB Trans Mountain Decision, by Richard King, Patrick Welsh and Rebecca Hall-McGuire, Case Comment, Energy Regulation Quarterly, Vol. 3, Issue 1 2015
  • Order Uncertainty: Are Courts Favouring Regulatory Orders Over Civil Claims To Achieve Environmental Protection? An examination of recent jurisprudential trends, by Dan Kirby, Jennifer Fairfax and Patrick Welsh, in Key Developments in Environmental Law 2014, Chapter 5 (Toronto: Carswell, 2014)
  • Climate Change as a Threat Multiplier: the U.S. Department of Defense Releases 2014 Climate Change Adaptation Roadmap, by C.W. Daniel Kirby, Patrick Welsh and Rebecca Hall-McGuire, Environment Law, Volume XII, No. 3 (Federated Press, 2014)
  • Balancing Caution and Pragmatism, Federal Court Finds “Gaps” in Darlington Environmental Assessment, Revokes License and Orders Reconsideration, by Terri-Lee Oleniuk, Jennifer Fairfax and Patrick G. Welsh, Case Comment, Energy Regulation Quarterly, Vol. 2 (September 15, 2014)
  • Sufficient Certainty? The Supreme Court of Canada Rules on Whether an Environmental Order Against an Insolvent Company Can be Stayed: Newfoundland and Labrador v. AbitibiBowater Inc., by Daniel Kirby, Edward Sellers, Jennifer Fairfax and Patrick Welsh, in Key Developments in Environmental Law 2013, Chapter 1 (Toronto: Carswell, 2013).