CITADEL EHS - Key Persons


Greg S. McIver

Job Titles:
  • Principal Scientist
  • PRINCIPAL SCIENTIST, ENGINEERING & ENVIRONMENTAL SCIENCES
Mr. McIver is a Principal Scientist, Co-Practice Lead and is on the Board of Directors at Citadel EHS. Mr. McIver has more than 25 years of experience in the environmental consulting field with a broad range of project experience including phase I/II site assessments, legal support, remedial pilot studies, remedial action design and implementation, vapor mitigation, bioremediation, cost to closure cost modeling, and risk sharing contracting structure. His portfolio includes varies types of industrial facilities, property transaction and redevelopment support, former dry cleaner facilities, fuel and service stations, railroads, DOD tank farms, irrigated lands, mines, and SCAP grants. The focus of Mr. McIver's experience is successful site closure strategy execution and effective regulatory management. Mr. McIver Co-Founded RMD Environmental Solutions in 2018, which sold to Citadel EHS in December of 2022. Mr. McIver is an active member of the Nevada County Search and Rescue Team.

Jack Samuels

Job Titles:
  • Associate Principal, Building Sciences

Jeff Klein

Job Titles:
  • Associate Principal, Refinery & Industrial Programs
Since 2003, Jeff has been the point person for a large Refinery located in Torrance, CA, managing the daily operations of the on-site Industrial Programs Team from Citadel. From technical and personnel oversight to advocating for his client, he also manages site audits, site investigations, expert witness testimonies, hazardous materials surveys, air monitoring management, and abatement project design.

Jeff Mistarz - CFO

Job Titles:
  • CFO
Mr. Mistarz has over 25 years of experience as a CFO guiding rapidly growing, small and mid-sized private and public companies, including a private equity-owned civil engineering firm ranked as the fourth fastest growing firm in the US for two years in a row and 14 years at a NASDAQ listed company. Over his career, Jeff has completed numerous financing transactions of all different forms and multiple M&A transactions. Jeff is responsible for Citadel's reporting, financing, M&A, and growth strategy formulation.

Julie Wojnowski

Job Titles:
  • Practice Lead, ESG & Sustainability

Kier DeLeo

Job Titles:
  • Citadel in 2015 As the Leader
  • Principal, Building Sciences
Kier joined Citadel in 2015 as the leader of Citadel's highly regarded Building Sciences group. Kier has over 20 years of experience in the environmental industry, holding management positions with both consulting and contracting firms. He has extensive experience in Building Sciences related work, Industrial Hygiene, moisture intrusion, and environmental due diligence. He is a recognized business leader, growing companies and practices through increased sales and client focus, process refinements and efficiency, new market penetration, and staff recruiting and development. Kier drives organizational change through a collaborative leadership style.

Kristina Krissakova

Job Titles:
  • ASSOCIATE PRINCIPAL, Sales and Marketing
Kristina has been working in the environmental consulting industry since early 2010, primarily in the areas of environmental due diligence, contaminated site assessment and remediation, and human health risk assessment. Kristina is originally from Slovakia, where she obtained her bachelor's and master's degree in environmental management and planning. Kristina's technical background allowed her to gain valuable experience in building and maintaining a professional network and sourcing of new clients, prior to her joining Citadel EHS in May of 2023. Kristina's role at Citadel EHS is to recognize and match client needs to the strong Citadel's skill set. In addition, Kristina assists with leadership, planning, organization, direction, coordination, and control to meet the sales revenue objectives of Citadel EHS. Kristina is responsible for initialization and management of relationships with clients in both the public and private sectors. In her free time, Kristina enjoys dancing, yoga, hiking, and skiing.

Loren Witkin - CEO

Job Titles:
  • CEO
Loren founded Citadel with the goal of creating an employee- and client-focused consulting firm that fused a thorough understanding of the built environment within the fields of environmental, health, and safety.

Lynn Eckes

Job Titles:
  • Principal, Accounting & Administration
Lynn has more than 40 years of financial management experience in the environmental and professional services industry. Her responsibilities range from corporate planning, budgeting, and accounting, to payroll, employee benefits, and human resources management. Lynn oversees the day-to-day stewardship of Citadel's finances to the benefit of all of our stakeholders. She also understands the company's culture, always looking to assist Citadel's newest talented professionals to assimilate quickly and enjoy job satisfaction while being part of a recognized "Best Places to Work" by the Los Angeles Business Journal.

Mark Drollinger

Job Titles:
  • Principal, Engineering & Environmental Sciences

Michael Roy

Job Titles:
  • Associate Principal, Building Sciences
Michael is a graduate of the Global Sustainability Certification Program at UCLA and currently leads a diverse team of Project Managers, Field Representatives, and Project Assistants. With 27+ years of extensive environmental-industry-related experience, Michael's core responsibilities include managing various clients, negotiating contracts, developing and implementing project programs, reviewing architecture strategy, and much more.

Michelle Torres

Job Titles:
  • Manager, Business Development / Marketing - Corporate Branding
A part of the Citadel team for 18+ years, Michelle honed her skills as an administrative assistant, eventually growing into her current role as manager. Her role is a vital one-she manages all corporate branding, marketing, social media and the planning plus execution of company events. She also oversees all IT support issues and communication.

Natasha Stratton

Job Titles:
  • Associate Principal, Industrial Hygiene & Safety
A dedicated leader, Natasha cultivates a motivating and empowering team environment that encourages everyone to exceed expectations. In her day-to-day, she ensures that Citadel's strategic vision is properly implemented, always pushing the core values while managing operations and logistics for the Industrial Hygiene and Safety team. Natasha has 18+ years of experience in the Environmental, Health, and Safety (EHS) industry, including over 12 years as a Citadel consultant. She leverages her skill and expertise as Associate Principal Industrial Hygienist to partner and collaborate with clients on a wide range of projects including: developing industrial hygiene sampling strategies; conducting health and safety program gap assessments; designing wildfire assessments and sampling strategies; performing occupational safety compliance audits; developing and implementing occupational safety programs; overseeing large-scale moisture investigation and mitigation efforts; and performing office and industrial ergonomic evaluations.

Scott Brehmer

Job Titles:
  • Principal, Industrial Hygiene & Safety
Scott joined Citadel in 2017 to lead our Industrial Hygiene and Safety practice areas. With over 20 years of consulting experience, serving in both technical and leadership roles, Scott adds important strategic and management consulting capabilities to the team. As the department leader, Scott provides vision for the future and inspires excellence in the present. He is particularly focused on delivering purpose-driven quality work, ensuring client satisfaction, and supporting the professional growth and well-being of his staff. As a Certified Safety Professional (CSP), Scott is best known for his ability to assess "all things safety" including culture, management processes, and safety performance of organizations. He supports all industries but is widely respected for his expertise in higher education including the University of California and California State University systems. Much of his career has been dedicated to improving laboratory safety and chemical hygiene on California college campuses. As a Certified Industrial Hygienist (CIH), Scott is an expert in protecting worker health. He excels in hazard recognition, industrial hygiene program development, exposure assessment, control strategies, and personal protective equipment (PPE) determinations. Scott believes in providing practical solutions that reduce employee exposure and have minimal impact on business operations and productivity. Scott seeks out clients that value employee health and safety and is passionate about helping companies improve performance and gain or maintain compliance.

Simon Turner

Simon Turner was CEO of Healthy Buildings, until June of 2019. He joined Healthy Buildings in 1987 after sales and research experience in the UK and South Africa. Healthy Buildings was sold to Underwriters Laboratories (UL) in June of 2019 at which time he resigned his post to consult as Founder of Building Cognition LLC, advising growing firms in his field. Turner is an SME in a wide range of indoor environmental disciplines and has a special interest in the relationship between indoor environments and productivity/human cognition. He has been on various global green building technical and steering committees. He currently serves on the BoD for the Green Building Initiative, operators of the GreenGlobes® sustainability programs, and on the Advisory Board for SafeTraces®, among other Board positions. He is a Life Member of the Building Owners and Managers Association (BOMA).