Deirdre A. Sheehan

Deirdre is Co-Chair of Osler's Regulatory, Indigenous and Environmental practice. Deirdre practices energy regulatory, Indigenous and environmental law and advises clients on the regulatory and environmental aspects of power, electricity, oil and gas and other energy developments, including regulatory proceedings for setting rates and tariffs. She advises on power transmission, distribution and generation projects in Alberta and regularly appears on behalf of clients before the Alberta Utilities Commission. Deirdre also has experience with matters before the Alberta Energy Regulator, the Canada Energy Regulator and other regulatory agencies and tribunals, including Alberta Environment and Protected Areas, the Alberta Environmental Appeals Board, the British Columbia Utilities Commission and the Yukon Utilities Board.

Deirdre has advised on power transmission lines, renewable and other power generation, oil and gas wells, pipelines, oil sands developments, upgraders, gas storage, and waste disposal facilities. She also has widespread experience in environmental impact assessments required under provincial and federal laws.

Deirdre's Indigenous law practice focuses on consultation, accommodation and participation of Indigenous groups in relation to large energy projects.

Deirdre also teaches Administrative Law at the University of Calgary.

Prior to joining Osler, Deirdre was a partner at another leading national law firm.


Representative Work

  • Canada Growth Fund

    The Canada Growth Fund in its connection with its carbon credit offtake agreement and $200 million strategic investment in Entropy Inc.

*Prior to joining Osler:

  • ATCO Electric Ltd., in transmission tariff proceedings before the Alberta Utilities Commission
  • Undisclosed client, in Canada Energy Regulator gas export licensing requirements and related issues
  • ATCO Electric Ltd., on all facility approvals before the Alberta Utilities Commission for an 80-kilometer 240 kV transmission line
  • Various clients, in Alberta Energy Regulator related matters, including with respect to gas storage projects, waste disposal and facility approvals for sweet and sour gas facilities, and hydraulic fracturing
  • ATCO Gas, a performance-based ratemaking regulated utility, before the Alberta Utilities Commission in respect of capital costs adjustments to be reflected in rates for 2014 and 2015
  • Undisclosed client, in Canada Energy Regulator compliance and investigation matters
  • Undisclosed client, in Alberta Energy Regulator compliance and investigation matters
  • Lead Counsel to Alberta PowerLine LP, a transmission facility owner, on all facility approvals before the Alberta Utilities Commission for the Fort McMurray West 500-kV Transmission Project, designated as Critical Transmission Infrastructure between Edmonton and the Fort McMurray area of Alberta, including in respective of environmental impact assessment and Indigenous consultation issues
  • Yukon Electrical Company Limited, in regulatory approvals and re-licensing of a hydro project before the Yukon Water Board, including in respect of environmental impact assessment and Indigenous consultation issues
  • A large oil and gas producer regarding First Nations consultation in relation to energy project developments on reserve lands and traditional lands of various First Nations in Alberta and British Columbia
  • Undisclosed client, in regulatory approvals for a solar project in Alberta
  • ATCO Utilities, in proceedings to establish the 2018-2020 Generic Cost of Capital for Alberta-based regulated utilities

Latest Insights

  • Osler Update Feb 29, 2024

    AUC inquiry update: Alberta to declare no-build zones and mandatory reclamation security requirements for renewable energy projects

    On February 28, Alberta announced intended changes to its electricity generation regime, including an “agriculture first” approach and buffer zones su...

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    AUC inquiry update: Alberta to declare no-build zones and mandatory reclamation security requirements for renewable energy projects
  • Osler Update Jan 30, 2024

    A surge of initiatives: developments in Alberta power and electricity policy to watch in 2024

    Last year saw several policy initiatives with the potential to significantly impact Alberta’s power and electricity framework. We look at some key ong...

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    A surge of initiatives: developments in Alberta power and electricity policy to watch in 2024
  • Osler Update Dec 11, 2023

    Proposed clean electricity regulations: is Canada staying in its lane?

    In support of international efforts to limit climate change, the Government of Canada is endeavouring to achieve a net-zero emissions national economy...

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    Proposed clean electricity regulations: is Canada staying in its lane?
  • Blog Nov 24, 2023

    B.C. government enforces ‘polluter pays’ principle with Environmental Management Act

    Who is considered an owner and what types of facilities are subject to amendments under British Columbia’s Environmental Management Act...

    Read more
    B.C. government enforces ‘polluter pays’ principle with Environmental Management Act
View all Insights

Awards and Recognition

  • Chambers Canada: Canada’s Leading Lawyers for Business: Recognized in Energy: Power (Regulatory)
    • “Deirdre is extremely knowledgeable and provides practical advice and guidance.”
    • “She looks at issues in a strategic manner and understands the commercial implications.”
    • “Deirdre provides smart and insightful support that is well thought out and reasoned – I can count on her for fantastic analysis.”
  • Legal 500: Recognized in Aboriginal Law, Energy and Natural Resources (Power)
  • The Canadian Legal Lexpert Directory: Recognized in Aboriginal Law, Energy (Electricity), Energy (Oil & Gas)

Media Mentions

  • Osler News Sep 25, 2023

    22 Osler lawyers recognized in Lexpert Special Edition: Energy 2023

    Osler is proud to announce that 22 of our lawyers are featured in the Lexpert Special Edition: Energy 2023, recognizing leading lawyers in the oil and...

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  • Osler News Feb 22, 2023

    Deirdre Sheehan joins Osler’s Regulatory, Indigenous and Environmental practice in Calgary as a partner

    Deirdre Sheehan has joined Osler’s Regulatory team in Calgary with extensive experience in the regulatory and environmental aspects of electricity, oi...

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Speaking and Writing

Speaking Engagements

speaker 28/3/2023
Indigenous Law Insights: Métis Nation within Alberta self-government agreement and negotiating with the Canadian government
Read more

Jasper Research Seminar 2024
Speaker, The Push for Electrification and a Net Zero Grid – Developments, Reactions and Implications, June 13, 2024 (with Vivek Warrier and Laura Scott)

Published Work

  • First Nations increasingly moving from accommodation to equity and shared ownership:  On energy projects, courts are putting new spin on the duty to consult, Lexpert (October 5, 2022)
  • Ermineskin decision involving Coalspur mine adds novel twist to the duty to consult, by David Bursey and Deirdre Sheehan, Canadian Mining Journal (October 8, 2021)
  • Limiting the right to procedural fairness: New Alberta regime expands administrative powers and penalties (Deirdre Sheehan, Brynne Harding, Patrick Schembri (26 may 2021)
  • Environmental and Regulatory Issues during the COVID-19 Pandemic“, presentation to the CBA Environmental Law Section South (April 20, 2020)

Credentials

Education

  • University of Victoria, LLB, 2001
  • University of Alberta, BEd, 1996

Languages

  • English

Professional Affiliations

  • Law Society of Alberta
  • Canadian Bar Association (Administrative Law, Alberta South, Executive Member)