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

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.

Greg S. McIver

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.

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).

Jeff Mistarz

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.

Janet Peters

Ms. Peters has over 35 years of experience in the engineering and environmental consulting industry ranging from Project and Client management to Business Unit and Operational and Divisional Leadership and Board positions. After serving as President of Ensero Solutions, Inc., where she was key in helping the company buy itself out from their former parent and setting up and managing all aspects of the business, she recently moved to a Board of Directors position. Previously, Ms. Peters held executive positions for Arcadis including the Environmental (Resilience) Division Director reporting to the CEO, and Chairman of the Board of the Lovinklaan Foundation, the largest Shareholder of ARCADIS NV. Ms. Peters is well versed in developing and implementing strategic plans providing for company growth, improved client development and satisfaction, and employee satisfaction and retention. She also provides a variety of services for M&A and operational support to companies to ensure short and long-term growth goals are met.

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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

Practice Leader, 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

Practice Leader, Environmental Compliance

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].

Julie Wojnowski

practice leader, esg & Sustainability

Mrs. Wojnowski comes to Citadel EHS after working 10-years with the International WELL Building Institute (IWBI). She also has 10+ years’ experience as a nurse. She’s based just outside of Charlotte, NC. Julie is an expert in the WELL Building Standard (WELL), human health, healthcare, business and revenue operations, third-party professional accreditation (ISO/IEC 17011), and third-party certifying body programs (ISO/ICE 17060 & 17065.) Julie is known for her ability to develop and grow products, programs and teams, most notably the WELL AP credential, WELL Performance Verification and the WELL Performance Testing program and the Network Care team at IWBI.  

You can reach Julie 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].

Greg S. McIver

PRactice Leader, 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.

You can reach Greg 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].

Kirsten Duey

Associate Practice Leader, Engineering and Environmental Sciences

Ms. Duey has more than 20 years of technical and project management experience in the environmental field.  She  provides a unique blend of superior project management, technical expertise, and open communication skills.  She has acted as manager or project engineer on a wide range of projects including soil and groundwater investigations, feasibility studies, remedial action plans, and site closures.

Her portfolio of projects includes design and implementation of numerous remedial approaches, including air sparging, soil vapor extraction (SVE), pump and treat, chemical oxidation, permeable active barriers, in-situ anaerobic biodegradation, and monitored natural attenuation programs. She has significant petroleum chlorinated volatile organic compounds (VOC) experience and has worked with a number of regulatory agencies in the California Bay Area to successfully negotiate site closures and remedial curtailment requests for chemical facilities, dry cleaners, redevelopment sites, and other commercial facilities.

You can reach Kirsten at: [email protected]

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