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Patrick G. Welsh

Patrick G. Welsh

Associate, Regulatory, Environmental, Aboriginal and Land; Litigation

Key Contact: Municipal, Land Use Planning & Development

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 provides practical advice and solutions to businesses regarding matters related to the environment and environmental laws, including brownfields redevelopment, waste diversion, transportation of dangerous goods and hazardous wastes, emissions and discharges, contaminated lands, records of site condition (RSC), risk assessments, maritime pollution and spills, regulatory orders, waste and soil, asbestos and other designated substances, and general environmental regulatory compliance. He frequently provides environmental advice to clients on commercial transactions, including land transactions, mergers and acquisitions, debt and equity offerings, and insolvencies and restructurings. Patrick also provides advice on land use planning matters, particularly as they relate to environmental issues. Patrick regularly works with environmental scientists and land use planners to address clients’ business needs. He was recognized in Chambers Canada (2019, 2020) as a Leading Lawyer (Associate to Watch) in its national “Environment” category and in Best Lawyers 2020 for Environmental Law, and was named a Rising Star for "Environment" in Legal 500 Canada 2020. 

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.

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 law student in 2009 and articled with the firm in 2010-2011, which included a secondment to the legal department of the Royal Bank of Canada.

  • Enterprise Holdings Inc.

    Enterprise Holdings Inc. in its Canadian subsidiary's acquisition of Discount Car and Truck Rentals

  • RBC Capital Markets

    RBC Capital Markets in CAPREIT’s $490 million public offering

  • RBC Capital Markets

    The syndicate of underwriters in European Residential REIT’s $167 million offering

  • Ventas, Inc.

    Ventas in its acquisition of a high quality Canadian seniors housing portfolio valued at $2.4 billion in partnership with Le Groupe Maurice

  • Rideau Inc.

    Rideau in its addition to Engage2Excel Group of Companies

  • UPL Limited

    UPL Limited in its US$4.2 billion acquisition of Arysta LifeScience

  • Essar Steel Algoma

    Algoma Steel Inc. and certain senior secured term lenders in Canada in Algoma’s acquisition of substantially all the assets of Essar Steel Algoma in connection to a restructuring under the CCAA

  • Maple Leaf Foods Inc.

    Maple Leaf Foods Inc. in its acquisition of select poultry assets from Cericola Farms

  • TransAlta Renewables Inc.

    The underwriters in the $150 million bought deal offering of TransAlta Renewables Inc. common shares by way of a prospectus supplement filed on June 15, 2018.

  • GFL Environmental Inc.

    Investors led by BC Partners and Ontario Teachers' Pension Plan in the $5.125 billion recapitalization of GFL Environmental Inc.

  • Blackstone Property Partners

    Blackstone Property Partners in its acquisition of Pure Industrial Real Estate Trust for $3.8 billion

  • Dominion Diamond Corporation

    Lenders and underwriters in the acquisition of Dominion Diamond Corporation by Washington Companies Corp.

    • TC Energy in land acquisitions and land use planning and development matters related to Ontario pipeline projects.
    • A US automotive manufacturer in multiple environmental matters relating to emissions and discharges and the transportation of dangerous goods.
    • A Canadian retailer in the sale of over 200 retail gas stations.
    • 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.
    • 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.
  • Find More

  • Chambers: Ranked in Chambers Canada: Canada's Leading Lawyers for Business: Associates to Watch, Environment
  • Best Lawyers: Ranked in Best Lawyers in Canada: Environmental Law
  • Legal 500: Ranked a "Rising Star" in Environment
  • Queen's University: Agnes Benidickson Tricolour Award
  • Queen's University: Gavel Award

  • 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).