WE ARE 100% EMPLOYEE OWNED.
We are 100% Committed to Sharing What we Make with Those that Make it.

WE ARE 100% EMPLOYEE OWNED.
We are 100% Committed to Sharing What we Make with Those that Make it.

  • Leadership Team
  • Board of Directors

Loren Witkin

CEO
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Jeff Mistarz

CFO
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Scott Brehmer

Principal, Industrial Hygiene & Safety
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Nalinna Rasu

Principal, Engineering & Environmental Sciences
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Ravi Bajaj,

WELL AP, LEED AP O+M, LEED AP BD+C
Principal, ESG/Sustainability
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Mark Drollinger

Principal, Engineering & Environmental Sciences
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Kier DeLeo

Principal, Building Sciences
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Bruce Thrupp

Principal, Business Development
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Lynn Eckes

Principal, Accounting & Administration
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Natasha Stratton

Associate Principal, Industrial Hygiene & Safety
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Michael Roy

Associate Principal, Building Sciences
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Jack Samuels

Associate Principal, Building Sciences
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Jeff Klein

Associate Principal, Refinery & Industrial Programs
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Michelle Torres

Manager, Business Development/Marketing - Corporate Branding
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Glenn Fishler

With 30+ years of leadership and board room experience, Glenn Fishler brings extensive experience in operational excellence, building leadership teams, sales & marketing, growth strategies, and board room governance to Citadel.  Glenn served as Chairman, President & CEO of EORM, a leading EHS management and technical consulting firm.  Over a 25-year span, Glenn led the growth of EORM to $30M/year in revenue with 165 employees.  In 2015, London-based BSI Group acquired EORM forming BSI EHS Services and Solutions. Between 2015 and 2017, Glenn led a buy + build growth strategy for BSI, which resulted in more than doubling the size of BSI’s EHS consulting business, before he retired from BSI in August 2017.

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).

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Loren Witkin, CAC, CDPH, LEED AP

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.

As part of his vision to bring all employees into ownership roles, Loren drove the formation of the firm’s ESOP in 2003 while simultaneously overseeing all phases of corporate development, client management, and complex project management across multiple disciplines.

A creative and focused leader, Loren has 30+ years of experience in the Environmental, Health, and Safety (EHS) industry, both in the public and private sectors, with numerous state, federal, and industry accreditations and certifications to his name. During his career, Loren has served as a panel member, speaker, and presenter on various EHS matters to universities, public agencies, cities, school districts, and industry conferences nationwide. He held tenure at UCLA as one of the first asbestos/lead program managers in California, where he developed policies relating to the identification and remediation of environmental contaminants for 17+ million square feet of property. He is also a founding member of both the California Medical Association Ad Hoc Committee on Lead and the California Chapter of the National Lead Abatement Council, where he currently takes an active role in the advancement of community awareness for lead poisoning.

Aside from his current CEO duties, Loren devotes his time to sitting on the City of Hope’s LA Real Estate Council, the Downtown Breakfast Club, AJU’s Real Estate Executive Council, and the Central City Association.

You can reach Loren at: [email protected].

Jeff Mistarz

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.


You can reach Jeff at: [email protected].

Scott Brehmer, MPH, CIH, CSP

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.

You can reach Scott at: [email protected].

Nalinna Rasu, CAC, CDPH, CHMM, LEED AP

Principal, Engineering & Environmental Sciences

An expert in the environmental industry since 2004, Nalinna has a broad range of technical specialties that focus on maintaining and promoting the health of those within a built environment, including environmental compliance; hazardous materials and waste management and inventorying; storm water sampling; air emissions reporting and permitting; asbestos and lead materials management; indoor air quality testing, both non-LEED and LEED; chemical exposure sampling; microbiological investigations; and NPDES permitting.

She has extensive experience in developing business and contingency plans for hazardous materials management (CUPA) and spill prevention (SPCC), as well as overall project management experience in conducting surveys for environmentally-regulated materials such as asbestos-containing materials, lead-based paint, PCBs, universal wastes, and Ozone Depleting Substances. A key component of this includes conducting on-site environmental compliance investigations to identify and assess existing hazardous materials that may be impacted by renovations and/or demolition projects.

You can reach Nalinna at: [email protected].

Ravi Bajaj, WELL AP, LEED AP O+M, LEED AP BD+C

Principal, ESG/Sustainability

Ravi joined Citadel in 2021 as a principal of Citadel’s newest practice area: ESG and Sustainability. Ravi has over 10 years of experience in Sustainability, ESG, and Health & Wellbeing consulting for the built environment. He has extensive experience in collaborative project management for the GRESB, WELL, LEED, and BREEAM In-Use rating systems, direct experience with WELL Performance Verification and BREEAM on-site assessments, as well as experience with the Fitwel and Living Building Challenge rating systems.

Ravi is focused on a data-driven approach to building performance measurement and continuous improvement programs, at the building and portfolio-scale. He is passionate about benchmarking performance and ESG reporting specific to the built environment, and about corporate sustainability and responsibility programs.

Ravi teaches about green building programs at the University of California at San Diego, is on the Board of Directors for the San Diego Green Building Council, and participates regularly in programs and advisory groups with industry organizations throughout Southern California.

You can reach Ravi at: [email protected].

Mark Drollinger, M.Eng, CSP, CHMM, EiT

Principal, Engineering & Environmental Sciences

As Principal of Engineering and Environmental Sciences, Mark has a level of expertise and experience accomplished by few, with a strong knowledge of EPA, AQMD, OSHA, and DOT regulations. He brings 35 years of managing Environmental, Health, and Safety (EHS) projects to the team.

A key negotiator for local, state, and federal agencies, Mark is accustomed to coordinating a complex array of multi-disciplinary project teams, while also taking on various high-level responsibilities: developing and implementing health and safety protocols; overseeing all engineering and geological science projects; and coordinating with his project managers and staff to solve the sometimes typical, but often complex and specific needs of each client.

You can reach Mark at: [email protected].

Kier DeLeo, CHMM

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.

You can reach Kier at: [email protected].

Bruce Thrupp

Principal, Business Development

Mr. Thrupp has 25 years of environmental industry experience ranging from business and corporate strategy development to technical program and project management. His experience includes building and managing corporate business development programs for multi-office, national environmental companies, and developing and managing major public and private sectors contracts for environmental engineering and consulting firms. He has a bachelor’s degree in geology and an MBA.

Bruce’s role at Citadel is to match client needs to the strong Citadel team member skill set to guarantee the provision of responsive, reliable and objective-serving solutions. Our collective goal is to build a foundation that ensures an excellent experience for all of our key stakeholders – our customers, our employees, the community and the environment.

In his free time, Bruce enjoys solo, off-trail high altitude trekking in California’s Sierra Nevada range.

You can reach Bruce at: [email protected].

Lynn Eckes

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.

You can reach Lynn at: [email protected].

Natasha Stratton, MS

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.

You can reach Natasha at: [email protected].

Michael Roy, CAC, CDPH

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.

You can reach Michael at: [email protected].

Jack Samuels, CAC, CLC

Associate Principal, Building Sciences

Jack’s expertise spans 29+ years in the hazardous materials and construction sphere, where his primary responsibility has always been consulting services. He manages a diverse staff of Certified Asbestos Consultants, Certified Site Surveillance Technicians, and Certified Lead Consultants who work together on client communication, project evaluation and design, project cost and scheduling, contract administration, and the overall management of environmental issues that come up through renovation and demolition construction projects.

Jack has managed numerous high-profile projects for clients like Macy’s, Hines, CIM Group, the Port of Los Angeles, Topa Management Company, and CBRE (United States Commercial Real Estate Services). He is regularly involved in hazardous materials surveys; scope preparation; bid specification plus plan preparation; environmental construction management; environmentally-regulated materials building surveys; supervising and managing projects; operations and maintenance projects; report writing and reviews; and project engineering.

You can reach Jack at: [email protected].

Jeff Klein, CAC, CDPH

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 has overseen all facets of asbestos, lead, Industrial Hygiene, SCAQMD Rule 1166 and moisture intrusion projects. Moreover, he has assisted in SCAQMD audit compliance, Procedure 5 responses, waste management and the supervision of refinery turnaround. As a result, is a crucial member of Citadel’s Emergency Response Team.

You can reach Jeff at: [email protected].

Michelle Torres

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.

You can reach Michelle at: [email protected].

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