ENMAX Executive and Leadership Team

June, 2026

Leadership Overview

ENMAX has 9 executives leading key functions including strategy, information technology, finance, human resources, legal, and regulatory affairs.

Driven by a commitment to reliable energy, ENMAX powers the lives of Calgary residents through integrated electricity generation, transmission, and distribution, fostering a sustainable energy future for the region.

Leadership Roles at ENMAX

  • President & Chief Executive Officer - Mark Poweska
  • President & Chief Executive Officer - Ken Bosma
  • Chief of Staff & Chief Executive Officer, Office of - Melissa Halderman
  • Chief Financial Officer & Executive VP, Finance - Sheri Primrose
  • President - Edwin Suazo
  • President - Demtri Ontisa
  • Chief Information Officer - Tony Rizzuti
  • Executive Vice President & Chief Human Resources Officer - Patricia MacDonald
  • Senior Vice President, Regulatory and Chief Legal Officer - Sarah Stevens
  • Mark Poweska - President & Chief Executive Officer

    Mark Poweska, the President & Chief Executive Officer at ENMAX, directs the company's overall strategic vision and operational execution. Poweska guides ENMAX's commitment to providing reliable electricity generation, transmission, and distribution services to Calgary residents. This leadership role involves fostering innovation in energy solutions and ensuring the company's long-term growth and sustainability within the Alberta energy market. Overseeing all major corporate initiatives, Mark Poweska ensures alignment with regulatory requirements and stakeholder expectations. The executive's focus extends to driving operational efficiencies and enhancing customer service across all facets of the utility's operations. By championing a forward-thinking approach, Poweska positions ENMAX to meet evolving energy demands and contribute positively to the community's energy infrastructure.

    Ken Bosma - President & Chief Executive Officer

    Ken Bosma, the President & Chief Executive Officer at ENMAX, drives the company's strategic direction and operational performance. Bosma oversees ENMAX's core business of electricity generation, transmission, and distribution, serving the Calgary community. This executive leadership position involves steering the company through dynamic market conditions and ensuring the delivery of essential energy services. Ken Bosma's responsibilities include fostering a culture of safety and reliability, critical for a utility provider. The executive's mandate encompasses expanding ENMAX's service offerings and enhancing its infrastructure to meet future energy needs. Through strategic decision-making, Bosma ensures the company's financial health and its continued contribution to Alberta's energy sector.

    Melissa Halderman - Chief of Staff & Chief Executive Officer, Office of

    Melissa Halderman, the Chief of Staff & Chief Executive Officer, Office of at ENMAX, provides strategic support and operational oversight to the executive leadership team. Halderman facilitates the execution of key corporate initiatives, ensuring alignment across departments involved in ENMAX's electricity generation, transmission, and distribution services for Calgary. This role involves managing critical projects, optimizing internal processes, and enhancing communication channels between leadership and operational teams. Melissa Halderman's responsibilities extend to driving strategic planning efforts and ensuring the efficient functioning of the CEO's office. By coordinating cross-functional efforts, Halderman supports ENMAX's commitment to reliable energy delivery and its strategic growth objectives within the Alberta energy sector.
    Melissa Halderman

    Sheri Primrose - Chief Financial Officer & Executive VP, Finance

    Sheri Primrose, the Chief Financial Officer & Executive VP, Finance at ENMAX, directs the company's financial strategy and fiscal operations. Primrose oversees all aspects of financial planning, accounting, treasury, and risk management for ENMAX's electricity generation, transmission, and distribution business. This executive position is crucial for maintaining the financial health and stability of the organization, ensuring robust capital allocation and investment strategies. Sheri Primrose's leadership ensures compliance with financial regulations and drives initiatives to optimize profitability and shareholder value. The Chief Financial Officer's responsibilities include managing budgets, forecasting financial performance, and providing critical financial insights to support strategic decision-making. Primrose plays a key role in securing funding for infrastructure projects and supporting ENMAX's long-term growth.
    Sheri Primrose

    Edwin Suazo - President

    Edwin Suazo, the President at ENMAX, directs key operational segments and strategic growth initiatives for the company. Suazo oversees specific business units critical to ENMAX's electricity generation, transmission, and distribution operations, ensuring efficient service delivery to Calgary residents. This leadership position involves driving performance improvements and fostering innovation within assigned areas of responsibility. Edwin Suazo's focus includes enhancing operational effectiveness and ensuring alignment with the company's overall mission. The President's mandate involves managing cross-functional teams and collaborating with other executives to achieve corporate goals. Suazo plays a vital role in executing strategic plans and maintaining ENMAX's commitment to reliability and customer satisfaction in the energy sector.

    Demtri Ontisa - President

    Demtri Ontisa, the President at ENMAX, spearheads critical operational functions and strategic development within the organization. Ontisa manages specific divisions responsible for ENMAX's electricity generation, transmission, and distribution services, ensuring seamless operations and service excellence for the Calgary region. This executive role involves driving operational efficiency, implementing strategic projects, and fostering a culture of continuous improvement. Demtri Ontisa's leadership focuses on optimizing resource allocation and enhancing the company's service delivery capabilities. The President's responsibilities include overseeing key performance indicators and ensuring that departmental objectives align with ENMAX's broader business strategy. Ontisa contributes significantly to the company's mission of providing reliable and sustainable energy solutions.

    Tony Rizzuti - Chief Information Officer

    Tony Rizzuti, the Chief Information Officer at ENMAX, architects and executes the company's technology strategy. Rizzuti oversees the development and maintenance of robust IT infrastructure essential for ENMAX's electricity generation, transmission, and distribution operations in Calgary. This critical role involves ensuring data security, system reliability, and the implementation of innovative digital solutions to enhance operational efficiency and customer experience. Tony Rizzuti's leadership drives the integration of advanced technologies that support the company's mission of providing dependable energy services. The Chief Information Officer's purview includes managing IT budgets, leading technology teams, and aligning digital initiatives with ENMAX's broader business objectives. Rizzuti ensures that technology empowers ENMAX to meet regulatory demands and adapt to the evolving energy landscape.
    Tony Rizzuti

    Patricia MacDonald - Executive Vice President & Chief Human Resources Officer

    Patricia MacDonald, the Executive Vice President & Chief Human Resources Officer at ENMAX, leads the company's human capital strategy and organizational development. MacDonald oversees all HR functions, including talent acquisition, employee relations, compensation and benefits, and learning and development, supporting ENMAX's electricity generation, transmission, and distribution workforce. This executive role is vital for cultivating a high-performing culture and ensuring ENMAX has the skilled personnel necessary to deliver reliable energy services to Calgary. Patricia MacDonald's focus includes implementing HR policies that promote employee engagement, diversity, and inclusion. The Chief Human Resources Officer's responsibilities encompass workforce planning, succession management, and ensuring compliance with labor laws. MacDonald drives initiatives that support employee well-being and professional growth, aligning human resources with ENMAX's strategic objectives.
    Sarah Stevens, the Senior Vice President, Regulatory and Chief Legal Officer at ENMAX, provides expert legal counsel and oversees regulatory affairs for the company. Stevens manages all legal aspects of ENMAX's electricity generation, transmission, and distribution operations, ensuring compliance with provincial and federal regulations. This executive position is critical for navigating the complex regulatory landscape of the energy sector and safeguarding the company's legal interests. Sarah Stevens' responsibilities include advising on corporate governance, contract law, and risk mitigation strategies. The Chief Legal Officer's purview extends to managing litigation and ensuring adherence to all legal and regulatory frameworks. Stevens plays a pivotal role in shaping ENMAX's regulatory strategy and maintaining its license to operate.

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    Frequently Asked Questions Regarding ENMAX Top Executives and Leadership Team

    Who leads ENMAX?
    ENMAX is led by Mark Poweska (President & Chief Executive Officer), along with executives such as Ken Bosma (President & Chief Executive Officer) and Melissa Halderman (Chief of Staff & Chief Executive Officer, Office of).
    Who is part of ENMAX’s executive team?
    The executive team of ENMAX includes leaders such as Mark Poweska (President & Chief Executive Officer), Ken Bosma (President & Chief Executive Officer), Melissa Halderman (Chief of Staff & Chief Executive Officer, Office of) and other senior executives.
    How many executives does ENMAX have?
    ENMAX has 9 executives leading key business areas.
    What roles are included in ENMAX’s leadership team?
    The leadership team of ENMAX includes roles such as President & Chief Executive Officer, President & Chief Executive Officer, Chief of Staff & Chief Executive Officer, Office of, Chief Financial Officer & Executive VP, Finance, President.