Patrick G. Welsh

Patrick G. Welsh

Partner, Regulatory, Environmental, Indigenous and Land; Litigation

Key Contact: Municipal, Land Use Planning & Development

Contact Information

tel: 416.862.5951



Patrick provides practical advice and solutions to businesses regarding matters related to the environment and environmental laws. He has been 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's practice includes 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.

Patrick frequently provides environmental advice to clients on commercial transactions, including land transactions, mergers and acquisitions, debt and equity offerings, and insolvencies and restructurings. He 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. 

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.

  • Bailey International

    Bailey International in connection with its acquisition of Hydrolico International

  • Zebra Technologies

    Zebra Technologies in its acquisition of Matrox Imaging

  • Goldman Sachs Asset Management

    Goldman Sachs Asset Management in its US$250 million investment in Hydrostor

  • Kinross Gold Corporation

    Kinross Gold Corporation in its US$1.4 billion acquisition of Great Bear Resources

  • TransUnion

    TransUnion in its $638 million acquisition of Sontiq

  • Deerfield Specialty Papers Inc.

    Deerfield Specialty Papers in connection with the sale of Glassine Canada to Nordic Paper Holding.

  • Domtar

    Domtar in its $3 billion acquisition by Paper Excellence

  • TopBuild

    TopBuild in its $1 billion acquisition of Distribution International

  • Aceto

    Aceto in its acquisition of A&C

  • Battle North Gold Corporation

    Battle North Gold Corporation in its acquisition by Evolution Mining Limited

  • Longo's

    Longo’s in its acquisition by Empire Company Limited

  • The Estée Lauder Companies Inc.

    The Estée Lauder Companies Inc. in its agreement to increase its ownership in DECIEM Beauty Group Inc.

  • Drax Group plc

    Drax Group plc in its acquisition of Pinnacle Renewable Energy

  • Imperial Oil

    Imperial Oil in its pipeline approval (leave to construct) from the Ontario Energy Board

  • 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

  • Find More

  • IFLR Rising Stars Awards: Recognized as a Rising Star in Environment (2020 Americas)
  • Chambers Canada: Canada's Leading Lawyers for Business: Recognized in Environment
  • Best Lawyers in Canada: Recognized in Energy Regulatory Law; Environmental Law
  • Legal 500: Recognized as a "Rising Star" in Environment
  • Queen's University: Recognized with the Agnes Benidickson Tricolour Award and the Gavel Award

  • Law Help Ontario, Duty Counsel Volunteer

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

  • Time for Parliament to Speak Up: Environmental Regulatory Orders in the Wake of Redwater, by Jennifer Fairfax, Patrick Welsh, Melanie Gaston, David Williams, and Marleigh Dick (Toronto: Carswell, 2019)
  • Canada Targets Implementing a Comprehensive Ban on Asbestos and Asbestos-Containing Materials by 2018, by Jennifer Fairfax, Patrick G. Welsh, Rebecca Hall-McGuire and Isabelle Crew, in Key Developments in Environmental Law, Chapter 1 (Toronto: Thomson Reuters Canada Limited, 2017)
  • 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).